Tag Archives: dairy

The Paleo Diet is not anything new. It has been around for centuries. At its core, The Paleo Diet takes food back to its roots, sometimes literally. Whole foods, lean protein, organic and non-GMO foods are the basis of a paleo diet.

Going Paleo is a choice that will positively affect your entire life. By eliminating excess sugars, added preservatives, and processed foods, your diet is filled with nutrient- and mineral-rich sustenance.

But with all the research available on print and online, there are still many questions that sceptics of The Paleo Diet have. Here is a list of some of the most frequently asked questions and answers to help you understand The Paleo Diet.


1. Eaton, S. B., L. Cordain and S. Lindeberg. Evolutionary Health Promotion: A Consideration of Common Counterarguments. Preventive Medicine. 2001. 34: 119-23.
2. Pinheiro, M. M., T. Wilson. Dietary Fat: The Good, the Bad, and the Ugly. Nutrition Guide for Physicians and Related Healthcare Professionals. 2017. 241-47.
3. Bernstein, A. M., et al., A Home-Based Nutrition Intervention to Increase Consumption of Fruits, Vegetables, and Calcium-Rich Foods in Community Dwelling Elders. Journal of the American Dietetic Association. 2002. 102(10): 1421-1427.
4. Hou, K. J., D. Lee, J. Lewis. Diet and Inflammatory Bowel Disease: Review of Patient-Targeted Recommendations. Clin Gastroenterol Hepatol. 2014. 12(10): 1592-1600.
5. Cordain, L. AARP The Paleo Answer: 7 Days to Lose Weight, Feel Great, Stay Young. 2012.
6. Masharani, U., et al. Metabolic and Physiologic Effects From Consuming a Hunter-Gatherer (Paleolithic)-Type Diet in Type 2 Diabetes. Eur J Clin Nutr. 2015. 69(8) 944-8.
7. Cordain, L., The Nutritional Characteristics of a Contemporary Diet Based Upon Paleolithic Food Groups. 2002. Jana 5(3): 15-24).
8. Poterba, M. J., S. F. Venti, D. A. Wise. The Asset Cost of Poor Health. The Journal of the Economics of Ageing. 2017. 9:172-84.
9. //thepaleodiet.com/bill-nye-science-guy. Accessed September 10, 2017.
10. //thepaleodiet.com/dr-cordain-responds-to-critics-of-a-recent-paleo-diet-study. Accessed September 10, 2017.

Eliminate Food Groups | The Paleo Diet
Do you believe that “our modern lifestyles, including nutrition, are the cause of current health problems?” If so, you could be susceptible to “fad diets,” according to the United Dairy Industry of Michigan (UDIM). Last week, the organization’s Technical Advisor for Nutrition, Lois McBean, wrote that those who follow the Paleo diet “are likely setting themselves up for nutritional deficiencies by eliminating entire food groups such as dairy, grains, and legumes.”1

McBean went on to observe, “Such restrictive diets are not consistent with current dietary recommendations including USDA’s MyPlate or the 2010 Dietary Guidelines for Americans.” It’s interesting that she invokes the 2010 Guidelines, considering that earlier this year, the Dietary Guidelines Advisory Committee (DGAC) acknowledged that the 2010 and previous Guidelines contain a glaring error.

In the DGAC’s own words, “Previously, the Dietary Guidelines for Americans recommended that cholesterol intake be limited to no more than 300 mg/day. The 2015 DGAC will not bring forward this recommendation because available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol.”2

The 2010 and previous Guidelines were wrong about cholesterol, a mistake that likely persuaded millions of people to avoid eggs, shrimp, and other healthy, cholesterol-rich foods. Is it conceivable that the Guidelines could also be wrong about dairy, cereals, and legumes? We’ll address this question, but first let’s examine the idea of “eliminating entire food groups.”

Eliminating Entire Food Groups

Paleo critics like McBean seem to think the USDA’s MyPlate is inclusive of all food groups, but surprisingly, it excludes the most nutrient dense food group of them all – organ meat. The Paleo diet, on the other hand, excludes dairy, cereals, and legumes because, despite the nutrients they contain, they also contain antinutrients and promote various adverse health effects. But what possible reason could the USDA and Paleo critics have for excluding organ meat?

In the US, organ meat fell out of favor decades ago, but in most other countries it’s embraced and recognized for its remarkably high nutrient levels. Those who worry about nutrient deficiencies should be questioning the exclusion of organ meat (an entire food group) before criticizing those who, for valid reasons, exclude dairy, cereals, and legumes.

Nutrient Deficiencies

McBean lauds dairy foods as “important sources of multiple essential nutrients, including calcium, vitamin D, and potassium,” while implying that the Paleo diet falls short on these nutrients. This is an interesting comment for three reasons:

1. Dairy is not a rich source of potassium

The charts below show potassium, vitamin D, and calcium levels for 100g portions of common foods. Paleo foods are highlighted in orange, non-Paleo foods in purple. All values are for uncooked foods; note that 100g doesn’t necessarily represent a serving size. For example, beans are richest in potassium, but once cooked, potassium is significantly diluted because the beans absorb so much water. As shown, Paleo foods, including vegetables, seeds, nuts, mushrooms, fruit, fish, and meat, provide plenty of potassium.

How much potassium is enough? The National Academy of Sciences (NAS) sets the Daily Recommended Intake (DRI) for all nutrients. For potassium, however, instead of a DRI they set an Adequate Intake (AI) level of 4.7g per day. The NAS notes, “dietary intake of potassium by all groups in the United States and Canada is considerably lower than the AI.”3 With so many potassium-rich foods to choose from (note: the chart is not comprehensive), the Paleo diet emerges as the solution for potassium deficiency, not the cause.

Potassium | The Paleo Diet

2. Most of dairy’s vitamin D comes through fortification

Vitamin D | The Paleo Diet[/one_half]

Dairy fat does contain a small amount of natural vitamin D, but non-fat and low-fat dairy have almost none. As shown in the chart, the foods highest in vitamin D are Paleo foods, namely fish, shrimp, eggs, and to a lesser degree organ meat and mushrooms. Even fortified dairy doesn’t provide spectacular amounts.

Furthermore, if you want to go the fortification route, you’re much better off with vitamin D supplements, in which case you could avoid the negative effects of dairy. Note that the DRI for vitamin D is 600 IU/day.

3. Dairy is indeed high in calcium, but the calcium story is nuanced

As Dr. Cordain has explained extensively, net calcium balance (NCB) is far more important than calcium intake. NCB equals calcium intake minus calcium excretion. Calcium excretion is largely a function of acid/alkaline balance. For diets with net acid loads, the body’s calcium salts, which are stored within the bones, are excreted to maintain balance. For diets with net alkaline loads, endogenous calcium stores are unaffected.

Calcium | The Paleo DietThe only alkalizing foods are vegetables and fruit. The Paleo diet is more alkaline than MyPlate because of its emphasis on vegetables and its exclusion of dairy, cereals, and legumes. As shown in the chart, calcium in the Paleo diet comes from seeds, nuts, bones, vegetables, and from the fact that proportionally less calcium is excreted, due to the diet’s alkalinity. Note that the DRI for calcium is 1,000 mg/day.

Despite its calcium levels, dairy causes more problems than it solves. According to the US National Library of Medicine, an estimated 65% of the global population is lactose intolerant.4 Additionally, drinking 3 cups of milk per day, as McBean and the UDIM recommend, is associated with an increased risk of bone fractures as well as increased overall mortality, according to a cohort study published by the British Medical Journal.5 This study was observational, so it cannot prove causation, but it underscores the net acid load problem and other problems associated with dairy.

Far from promoting nutrient deficiencies, a careful examination of the evidence shows the Paleo diet reverses nutrient deficiencies caused by junk food and other imbalanced diets. This is accomplished by eliminating problematic food groups, including dairy, cereals, and legumes, while embracing the healthiest food groups, including meat, fish, organ meat, vegetables, nuts/seeds, and fruit.


1. McBean, L. (November 4, 2015). Fad Diets: Be Careful What You Wish For. United Dairy Industry of Michigan.

2. Dietary Guidelines Advisory Committee. (February 2015). Scientific Report of the 2105 Dietary Guidelines Advisory Committee. USDA and Department of Health and Human Services.

3. National Academy of Sciences. Institute of Medicine. Food and Nutrition Board. (2004). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate.

4. Genetics Home Reference. (May 2010). “Lactose Intolerance.” U.S. National Library of Medicine.

5. Michaëlsson, K., et al. (October 2014). Milk intake and risk of mortality and fractures in women and men: cohort studies. The British Medical Journal, 349.

6. Schmid, A and Walther, B. (July 2013). Natural Vitamin D Content in Animal Products. Advances in Nutrition, 4(453-462).

Which Diet Best Supports Heart Health? | The Paleo Diet

“A healthy diet and lifestyle,” says the American Heart Association (AHA), “are your best weapons in the fight against heart disease.”1 But does the AHA’s recommended diet protect against heart disease better than other diets, particularly the Paleo diet?

Researchers from Eastern Michigan University (EMU) recently compared these two diets for a study published in Nutrition Research. They found that adherence to the Paleo diet for four months significantly decreases total cholesterol (TC), LDL cholesterol, and triglycerides, while increasing HDL cholesterol, compared to four months on the AHA’s recommended diet.

The AHA’s diet includes large amounts of whole grains and dairy, two food groups the Paleo diet, of course, eliminates. The AHA also discourages saturated fat, claiming, “Eating foods that contain saturated fats raises the level of cholesterol in your blood.”2 The current study, however, adds to a growing body of evidence suggesting saturated fat is heart healthy, whereas high-carbohydrate grain-based diets may worsen cardiovascular disease markers.

The EMU researchers recruited 10 men and 10 women between the ages of 40 and 62. Each had hypercholesterolemia (high cholesterol levels) and none were taking cholesterol-reducing medication. Each participant followed the AHA’s recommend diet for 4 months, followed by 4 months on the Paleo diet. Compared to baseline, TC decreased slightly (3%) following the AHA diet, followed by a “very large” 20% decrease from AHA to Paleo.3 Similarly, LDL reductions were “small” (3%) from baseline to AHA, followed by a “very large” 36% decrease from AHA to Paleo.

Weight loss occurred on both diets but was significantly better on the Paleo diet. For men, the AHA diet reduced mean body weight by 3.3 ± 2.7 kg, relative to baseline (P < .001), with an additional 10.4 ± 4.4 kg reduction following 4 months on the Paleo diet. For women, no significant weight reductions followed the AHA diet, but the Paleo diet resulted in significant 8.1 ± 5.9 kg reductions.

This study follows up on previous studies demonstrating improved lipid profiles based on Paleo diet adherence, including a 2009 study showing significant improvements after just 10 days on Paleo and another 2009 study showing significant improvements for type-2 diabetes patients following 3 months on Paleo. 4, 5 The current study, however, does have some limitations, which the researchers openly acknowledge, including a small sample size (20 participants) and the study’s racial homogeneity (predominantly white). Additionally, the study did not allow for order bias, meaning all participants first cycled through the AHA diet, followed by the Paleo diet.

Additionally, it would have also been interesting to see each diet’s impact on both small-particle and large-particle LDL. Measurements of total LDL can be misleading because small-particle LDL accumulates within the arterial walls, whereas large-particle LDL floats through the bloodstream and is generally considered benign.6 Saturated fat has been shown to change small-particle LDL into large-particle LDL.7 In this study, the Paleo diet decreased LDL cholesterol levels more than the AHA diet, but the study tells us nothing about changes in the small- and large-particle LDL.

The AHA’s recommended diet appears to be relatively ineffective for treating hypercholesterolemia. Besides encouraging an AHA-type diet, typical allopathic treatments for hypercholesterolemia often include statin drugs. Statins may reduce cholesterol favorably, but have numerous potential side effects, including myopathy, nausea, neuropathy, elevated liver enzymes, and increased risk of new-onset diabetes.8,9

With no risks and significant benefits, the Paleo diet seems to be the smartest approach to reversing hypercholesterolemia and generally improving heart health. You have nothing to lose and everything to gain going Paleo.



[1] Healthy Eating. American Heart Association. Retrieved from //www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Healthy-Eating_UCM_310436_SubHomePage.jsp

[2] Saturated Fats. American Heart Association. Retrieved from //www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Saturated-Fats_UCM_301110_Article.jsp

[3] Pastore, RL, et al. (June 2015). Paleolithic nutrition improves plasma lipid concentrations of hypercholesterolemic adults to a greater extent than traditional heart-healthy dietary recommendations. Nutrition Research, 35(6). Retrieved from //www.nrjournal.com/article/S0271-5317%2815%2900097-4/abstract

[4] Frassetto, LA, et al. (February 2009). Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. European Journal of Clinical Nutrition, 63. Retrieved from //www.nature.com/ejcn/journal/v63/n8/full/ejcn20094a.html

[5] Jonsson, T, et al. (July 2009). Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovascular Diabetology, 8(35). Retrieved from //www.cardiab.com/content/8/1/35

[6] Tribble, DL, et al. (April 1992). Variations in oxidative susceptibility among six low density lipoprotein subfractions of differing density and particle size. Atherosclerosis, 93(3). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/1590824

[7] Campos, H, et al. (February 1992). Low density lipoprotein particle size and coronary artery disease. Arteriosclerosis and Thrombosis, 12(2). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/1543692#

[8] Zhang, H, et al. (April 2013). Discontinuation of Statins in Routine Care Settings: A Cohort Study. Annals of Internal Medicine, 158(7). Retrieved from //annals.org/article.aspx?articleid=1671715

[9] Carter, AA, et al. (May 2013). Risk of incident diabetes among patients treated with statins: population based study. British Medical Journal, 346. Retrieved from //www.bmj.com/content/346/bmj.f2610

Red Meat, Insulin Sensitivity, and Sage Infused Mushroom Paleo Burgers | The Paleo Diet

Does red meat consumption increase your risk for developing type-2 diabetes? Some epidemiologic studies have suggested this much, while also linking increased dairy consumption with decreased type-2 diabetes risk.1 Insulin sensitivity is the proposed mechanism driving these associations.

People with low insulin sensitivity, also known as being insulin resistant, require greater amounts of insulin from the pancreas to stabilize blood glucose levels. Over time, insulin resistance promotes type-2 diabetes as the pancreas fails to satisfy the body’s insulin requirements. This causes excess glucose to build up in the bloodstream, thereby promoting type-2 diabetes.

Previously published epidemiological studies have led to the hypothesis that increased red meat consumption promotes lower insulin sensitivity, whereas increased dairy consumption promotes higher insulin sensitivity. This hypothesis, however, has not been tested via randomized controlled trials, until now.

For a study recently published in the American Journal of Clinical Nutrition, researchers tested three different diets on 47 overweight or obese men and women.2 The diets included a) a diet high in red meat with minimal dairy, b) a diet high in dairy with no red meat, and c) a diet with no red meat, nor any dairy. Each participant followed each diet for a period of four weeks.

Until now, few intervention studies have evaluated red meat and dairy for their effects on insulin sensitivity in the absence of weight loss. The researchers, therefore, designed this study to maintain weight stability so as to isolate the effects of red meat and dairy on insulin sensitivity. Their primary hypothesis was that the red meat diet would produce greater insulin resistance (lower insulin sensitivity) compared to the high-dairy diet.

To their surprise, the opposite happened. Fasting insulin was significantly higher after the high-dairy diet compared to the red meat diet. There was no change in fasting glucose, which means the high-dairy diet promoted greater insulin resistance (lower insulin sensitivity) than the red meat diet.

These findings run contrary to the hypothesis that red meat consumption increases your risk for type-2 diabetes. Red meat, as those who follow the Paleo lifestyle know, is an invaluable source of high-quality protein and fat, as well as various vitamins and minerals. Continue eating it and should you be short on inspiration, our Sage Infused Mushroom Burgers are an excellent place to start!



  • 1 lb lean ground beef
  • ¼ lb mushrooms
  • 2 tbsp fresh sage, chopped finely
  • 3 cloves garlic
  • 4 tbsp olive oil, divided
  • Freshly milled black pepper


1. Wash the mushrooms and chop them into quarters. 2. Place them on a baking sheet and roast at 350°F for 15 to 20 minutes, or until they reduce by half.
4 item(s) « 1 of 4 »

Christopher James Clark, B.B.A.
Nutritional Grail

Christopher James Clark | The Paleo Diet TeamChristopher James Clark, B.B.A. is an award-winning writer, consultant, and chef with specialized knowledge in nutritional science and healing cuisine. He has a Business Administration degree from the University of Michigan and formerly worked as a revenue management analyst for a Fortune 100 company. For the past decade-plus, he has been designing menus, recipes, and food concepts for restaurants and spas, coaching private clients, teaching cooking workshops worldwide, and managing the kitchen for a renowned Greek yoga resort. Clark is the author of the critically acclaimed, award-winning book, Nutritional Grail.



[1] Turner, KM, et al. (Mar 2015). Red meat, dairy, and insulin sensitivity: a randomized crossover intervention study. American Journal of Clinical Nutrition, 101(3). Retrieved from //ajcn.nutrition.org/content/early/2015/03/25/ajcn.114.104976.abstract

[2] Ibid. Turner

How Early Should Infants Eat Meat? | The Paleo Diet

An infant’s rate of weight gain during the first year of life can strongly predict obesity later in life.1 Various studies published in recent years have linked cow-milk protein with weight gain for infants.2, 3 Collectively, these studies have led to recommendations that protein should not exceed 15% of total energy during later-infancy and the second year of life.4 Such recommendations, however, don’t differentiate between dairy protein and protein from other sources. Could dairy protein be uniquely problematic, causing weight-gain problems not associated with meat protein? According to 2014 study published in the American Journal of Clinical Nutrition, yes.

Human breast milk contains progressively less protein during later-stages of lactation, particularly the 4-6 month window when infants start consuming complementary foods (while continuing to breastfeed). But how much protein should those complementary foods contain? Would a higher-protein diet be beneficial, provided the protein comes primarily from sources other than dairy? This was the hypothesis for the 2014 study mentioned above. Accordingly, the scientists tested complementary diets with both higher and lower amounts of protein, observing the effects on infants’ growth and their metabolic profiles.5

42 infants five or six months old were randomly assigned to one of two groups. For four months (six to nine months after birth), Group 1 (higher protein) ate complementary diets consisting of meat purees, whereas Group 2 (lower protein) ate iron- and zinc-fortified cereal purees. To qualify for the study, infants had to have had normal birth weights, be breastfed since birth, to continue being breastfed during the study, and no abnormalities nor conditions that would influence growth rate. For both groups, fruits, vegetables, yogurt, and cheese were also allowed (and continued breastfeeding was required). Energy intake for both groups was nearly identical, but with significant differences in macronutrient distributions. By the ninth month, the groups’ calorie consumption were:

How Early Should Infants Eat Meat? | The Paleo Diet

The study yielded two major findings. First, despite widely differing macronutrient ratios, caloric consumption between the two groups was nearly identical. This suggests that infants can effectively regulate energy intake; they’re not prone to overeating because they know when to stop. The second finding was that diets higher in protein are associated with greater linear growth and proportional weight gain. This is a key point. Dairy protein intake during infancy has been correlated with obesity by age seven. In other words, increased weight gain absent proportional linear growth.

So why would milk protein promote obesity/overweight but meat protein promote proportional height/weight gains? The answer is not entirely clear, but the study’s scientists propose two mechanisms. First, dairy, but not meat, could promote the stimulation of insulin-like growth factor I (IGF-I), which in turn could promote obesity/overweight. Second, meat provides plenty of bioavailable zinc and iron, whereas neither dairy nor breast milk provide these nutrients in quantities sufficient to meet the nutritional needs of older infants (greater than six months).6

Although the scientists acknowledge their study requires follow-up research, their findings “reinforce the potential value of introducing flesh foods early.” Indeed, the available research supports the Paleo diet during all stages of life, including infancy. Compared to dairy- and cereal-based complementary diets, meat fares best for infants after six months of breastfeeding. Meat promotes increased growth and proportional height/weight.

Christopher James Clark, B.B.A.
Nutritional Grail

Christopher James Clark | The Paleo Diet TeamChristopher James Clark, B.B.A. is an award-winning writer, consultant, and chef with specialized knowledge in nutritional science and healing cuisine. He has a Business Administration degree from the University of Michigan and formerly worked as a revenue management analyst for a Fortune 100 company. For the past decade-plus, he has been designing menus, recipes, and food concepts for restaurants and spas, coaching private clients, teaching cooking workshops worldwide, and managing the kitchen for a renowned Greek yoga resort. Clark is the author of the critically acclaimed, award-winning book, Nutritional Grail.



[1] Young BE, et al. (Sep 2012). Biological Determinants Linking Infant Weight Gain and Child Obesity: Current Knowledge and Future Directions. Advances in Nutrition, 3. Retrieved from //advances.nutrition.org/content/3/5/675.full

[2] Koletzko B, et al. (Jun 2009). Lower protein in infant formula is associated with lower weight up to age 2 y: a randomized clinical trial. American Journal of Clinical Nutrition, 89(6). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/19386747

[3] Escribano J, et al. (Apr 2012). Effect of protein intake and weight gain velocity on body fat mass at 6 months of age: the EU Childhood Obesity Programme. International Journal of Obesity (London), 36(4). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/22310472

[4] Michaelsen KF, et al. (Oct 2012). Amount and quality of dietary proteins during the first two years of life in relation to NCD risk in adulthood. Nutrition, Metabolism, and Cardiovascular Diseases, 22(10). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/22770749

[5] Tang M and Krebs N. (Oct 2014). High protein intake from meat as complementary food increases growth but not adiposity in breastfed infants: a randomized trial. American Journal of Clinical Nutrition, 100. Retrieved from //ajcn.nutrition.org/content/early/2014/08/13/ajcn.114.088807

[6] Krebs NF, et al. (Jul 2012). Comparison of complementary feeding strategies to meet zinc requirements of older breastfed infants. American Journal of Clinical Nutrition, 1(30). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/22648720

Q & A on Milk: mTORC

Dear Professor Cordain,

In regards the review paper of which you were co-author: “The impact of cow’s milk-mediated mTORC1-signaling in the initiation and progression of prostate cancer,” could you please inform me whether you are aware of any country’s medical community who has responded to your conclusive statement that: “…the medical community urgently needs to re-evaluate dietary milk recommendations.”

This has not occurred thus far in my country of Australia.

Please excuse me for further taxing your valuable time, but could you also inform me of the details leading to the changing of the designation of the ‘m’ in the mTORC acronym from ‘mammalian’ to ‘mechanistic’, as it appears in your co-author Bodo Melnik’s 2013 paper: “Milk is not just food but most likely a genetic transfection system activating mTORC1 signaling for postnatal growth.

Many thanks in anticipation.
Kind regards,

Dr. Ross Partington

Bodo Melnik’s Response:

Dear Dr. Partington,

Mammalian target of rapamycin (mTOR) has been renamed in an mTOR consensus conference to mechanistic target of rapamycin. The official nomenclature according to OMIM.org is now:



The mTOR protein or function has not changed also there are various synonyms, a matter of history in molecular biology.

Best regards,

Bodo C. Melnik, Ph.D
Department of Dermatology
Environmental Medicine and Health Theory
University of Osnabrück, Sedanstrasse

Dairy: Milking It for All It's Worth | The Paleo Diet

The Recent Evolutionary Introduction of Milk and Dairy

One of the rewarding benefits of having written a diet book that has become internationally known is the opportunity to travel the world and speak to tens of thousands of people about this engaging and life changing subject. My signature lecture, “Origins and Evolution of the Western Diet: Health Implications for the 21st Century” is based upon a scientific paper I wrote of the same name and published in The American Journal of Clinical Nutritionin 2005.24 In this lecture, I trace the chronological introductions of all the food groups and foods that have become part of the contemporary U.S. and western diet. When I lecture, I like to engage the audience so it becomes not just a solitary presentation by me, but rather a mutual give and take conversation among us all. When I get to the part about milk and dairy products, I pose a question to everyone, “How do we know that our hunter gatherer ancestors never ate this food group?” Some people furl their brows, scratch their heads and clearly are lost for words. In the ensuing pregnant pause before some raised hands can blurt out the correct answer – I flip to the very next slide. Immediately appears a ferocious, unruly herd of about 30 African Cape buffalo (both cows and bulls), snorting and pawing the earth with powerful hooves supporting their one ton bodies crowned by enormous menacing horns.

Enough said? Have you ever tried to approach a wild animal? How about milking one? Indeed – this is an impossible task to say the least. Until the dawn of agriculture 10,000 years ago and the subsequent domestication of dairy animals6, 18, 50 milk, butter, cheese and yogurt were never part of our ancestors’ menu.24, 35

Although 10,000 years ago seems unimaginably distant compared to a single human lifespan, it is very, very recent on an evolutionary time scale. Only 333 human generations have come and gone since we first domesticated animals (cows, sheep, and goats)6, 18, 50 and began to consume their milk. Consequently, as a species we have had scant evolutionary experience to adapt to a food that now comprises about 10 % of the calories in the U.S. Diet.24, 45 As such, milk and dairy products have an enormous potential to disrupt our health and well-being through a variety of means that I barely touched upon in my first book, The Paleo Diet. If you had any prior doubts about whether you should eat dairy foods, the information contained in this article should help you make an informed decision in the best interest of your health.

Milk and dairy products only became part of the current western diet during the period known as the Neolithic or “New Stone Age” which began about 10,000 years ago and ended 5,500 years ago. The figure below shows just how recent dairy foods and other staples of the western diet really are when evaluated on an evolutionary time frame.

Dairy | The Paleo Diet

Unless you are lactose intolerant, have an allergy to milk and dairy products, or have been a devoted follower of The Paleo Diet, most people don’t give a second thought about whether or not they should consume a food group that seems to be found nearly everywhere in the western diet. Your favorite dairy foods may include ice cream, chocolate milk, cheese, fruit flavored yogurt, kefir or fancy imported cheeses. You may even think that you are doing your body a favor by eating these calcium rich foods. Nevertheless, the bottom line is this: we are the only species on the planet to consume another animal’s milk throughout our adult lives. Humans don’t have a nutritional requirement for the milk of another species, nor do any other mammals.

An increasing body of scientific evidence supports the evolutionary caution that this dietary practice is not necessarily harmless. The table below shows the sources and amounts of dairy foods in the U.S. diet.45

Dairy | The Paleo Diet

These figures don’t entirely tell the full story, as dairy products are put into almost all processed foods. Take some time to read labels. If you are a milk chocolate addict, you are eating dairy – same for latte lovers. Non-fat milk solids, a major ingredient in chocolate, are also put into candy, cereal, bread, salami, bologna, sausages, baked goods, salad dressings, chips, condiments, soft drinks and literally any food that comes in a can, jar, bottle, bag or plastic wrapper. Even though these tiny residues of milk in processed foods seem to be trivial, you may want to reconsider. Later in this article I’ll show you how milk proteins and peptides (the building blocks of proteins) at even small concentrations have potential to promote allergies, inflammation, autoimmune diseases and other health problems.

The Milk Mustache Advertising Hype

Before I even get into the extensive science underlying milk’s unfavorable effect upon our health and wellbeing, let’s take a step back and look at the vast, hype advertising campaign that the milk processing industry has shoved down our throats for nearly 20-30 years. This glitzy promotional crusade called “Got Milk” depicts movie stars, sports personalities, politicians and just about any public figure you can imagine with a wet, white film of what appears to be milk on their upper lips. Implied in magazine ads, TV and radio commercials, and now social networks is the notion that all public figures with “milk mustaches” endorse dairy products, presumably because they are a healthy and nutritious food. Whoa! Let’s stop for a minute and touch bases with reality.

I haven’t drank a glass of milk in nearly 40 years, but if I were to, I certainly wouldn’t spill it all over my upper lip. I imagine that world class athletes, dancers and actresses with far better hand to eye coordination than I have, also would not make this clumsy maneuver. However, this issue really doesn’t matter and simply is part of the industry’s advertising strategy – if the movie stars and sports heroes do it, so should you. But more importantly, why would a Wimbledon tennis champion, an Oscar winning actress, or an Indy 500 race car driver blindly support a product they know virtually nothing about?

These public personas have spent their lifetimes honing talents, skills and knowledge specific to their life’s callings. But when it comes to understanding milk’s intricate influence upon our metabolism, hormonal function and long term health, most of these people are novices operating completely out of their areas of expertise without knowledge or understanding of the facts. You can’t really fault them for endorsing a product they know little or nothing about. Like the public at large, they have bought into the milk processing industry’s ad campaign portraying milk right along with motherhood, apple pie and the American way.

This is exactly the message the milk processing industry wants to convey to the general public because it sells more milk and dairy products – plain and simple. Is there a conspiracy by dairy industry middlemen, executives and CEOs to sabotage our health and promote disease? Of course not. These people by and large, just like the movie stars and sports figures who endorse milk, are uninformed and blindly believe in their product. They represent tiny cogs in a wheel that rolls directly in the face of at least 2.6 million years of evolutionary wisdom. To them, the “Got Milk” and “Milk Mustache” advertising campaigns simply represent a logical corporate tactic to increase sales and maximize profits of a supposedly nutritious and healthful product.

As was the case with saturated fats, whether or not people should consume dairy products is divisive within the scientific community because the human experimental and epidemiological evidence is not necessarily conclusive and still can be interpreted in a variety of ways. Does milk prevent disease, or does milk promote disease? Or is the answer somewhere in between? In an ideal world, this question could be decisively answered by well controlled human experimental studies conducted over entire lifetimes. Unfortunately, these hypothetical lifelong experiments in real people will never be carried out because they would be impossible to control, incredibly expensive and unethical. In lieu of these studies, conventional nutrition researchers are left with the four basic scientific procedures to unravel the milk drinking dilemma:

  1. Observational epidemiological studies
  2. Animal studies
  3. Tissue studies
  4. Short term human experiments.

Unfortunately, traditional nutrition researchers are unaware of, or don’t appreciate the most powerful research tool in all of biology. This concept could point them in the right direction when it comes to deciphering the conflicting information about dairy products and human health. By now you know what I’m talking about – the evolutionary template. Anybody who doesn’t use it, just as well may be running uphill in a football or soccer game or doing calculations with pencil and paper rather than a computer. When the evolutionary template is employed together with the four basic procedures scientists use to establish causality between diet and disease, then we can make sense of all the contradictory data and be pointed in the right direction of arriving at a correct answer.

Frank Oski, M.D.: A Pioneer Milk Researcher

Before I go any further, I’d like to bring up a quote that has influenced my thinking about science, biology, diet and life in general for most of my adult life:

“Those who cannot remember the past are condemned to repeat it.”— George Santayana105

I certainly am not the first scientist to recognize that milk and dairy consumption may have adverse effects upon our health. One of the most vocal opponents to milk drinking was a physician, Frank Oski M.D. (1932-1996) who served as the Department Chairman of Pediatrics at the State University of New York, Syracuse from 1972 until 1985 and as the Department Chairman of Pediatrics at Johns Hopkins University from 1985 until 1996. He was a member of the National Academy of Sciences and the author or co-author of about 300 academic papers and 20 books. A book he wrote in 1977 called Don’t Drink Your Milk,86 was decades ahead of its time. Here is a quote from this book which dovetails nicely with this article:

“The fact is: the drinking of cow milk has been linked to iron-deficiency anemia in infants and children; it has been named as the cause of cramps and diarrhea in much of the world’s population, and the cause of multiple forms of allergy as well; and the possibility has been raised that it may play a central role in the origins of atherosclerosis and heart attacks… In no mammalian species, except for the human (and the domestic cat), is milk consumption continued after the weaning period (the period of breast-feeding]. Calves thrive on cow milk. Cow milk is for calves.”

Evolutionary Clues to Cow Milk Consumption

When you apply the evolutionary template to milk drinking, it becomes absolutely clear that cow’s or any other mammal’s milk was never intended to nourish another species (i.e. humans) throughout their entire adult lives. Rather it was specifically designed by natural selection to encourage rapid growth, support immune function, and prevent disease in young suckling animals. New born calves, like most mammals are nearly helpless for the first few hours after birth. They are unable to stand up, much less sprint away from potential predators. For the first few days and weeks after birth, they can’t forage for food and are almost entirely dependent upon mother’s milk for nourishment.

Milk is designed to make young animals grow rapidly and to prime their immune systems and prevent disease by allowing hormones and other substances in their mother’s milk to enter their bloodstreams. This is a brilliant evolutionary strategy to encourage survival for young suckling animals at the beginning of their lives, but is a formula for disaster when adult animals (us) consume a food intended only for the young of another species.
One of the telltale signs that there may be something just a little awry with milk drinking is that about 65% of all people on the planet can’t do it without experiencing gas, bloating and digestive distress.60 Maybe we should be listening to our bodies? Many of you may have these symptoms and already know why they occur after drinking milk or eating dairy products, but let me explain the basic concept for those who don’t know.80, 116

Milk is a mixture of carbohydrate, protein and fat. Most of the carbohydrates in milk occur in the form of a sugar called lactose which in turn is made up of two simple sugars: glucose and galactose. When we consume milk, ice cream and other dairy products rich in lactose, it must first be broken down into these two simple sugars by an enzyme in our guts called lactase. As I mentioned earlier, about 65% of the world’s people haven’t inherited the genes to make lactase and are therefore lactose intolerant.60 The notable exception to this rule is people from Northern Europe and their descendants.80, 116 Because Northern Europeans maintain high gut lactase activity as adults, they can metabolize lactose into its two simple sugars and don’t experience gastro-intestinal upset after drinking milk. In the figure below you can see that the percentage of people with Northern European ancestry who can digest lactose without discomfort is much higher than almost all the other world’s people.80, 116

Dairy | The Paleo Diet

The evolutionary explanation for the information in this figure is quite simple. Most people on the planet can’t drink milk without gastrointestinal upset because their genes simply haven’t had enough time to adapt to this newcomer food.60, 80, 116 Milk represents foreign fare which lactose intolerant people reject, as should we all, whether we can digest lactose or not. The lactose evidence is like a canary in a coal mine, and hints at even greater health problems with milk and dairy consumption.

Milk and Dairy: Nutritional Lightweights

Based upon the dairy ad campaigns, bovine (cow) milk consumption appears to represent nothing less than an extraordinary food to perk up our health and avoid illness. This milky white liquid, served cold is touted as Good for Everybody and high in nine nutrients including calcium and vitamin D as listed on the milk processing industry’s website: www.gotmilk.com. If the truth be known, milk is a lousy source of vitamin D as well as the top 13 nutrients most lacking in the U.S. diet. Let’s take a look at the facts.

In a paper published in The American Journal of Clinical Nutrition,24 my research group and I pointed out how dairy products were nutritional lightweights when compared to lean meats, seafood, fresh fruits and vegetables. Based upon the 13 vitamins and minerals most lacking in the U.S. diet, our analysis showed that whole milk ended up near the bottom of the stack for all food groups. The highest source of these 13 nutrients were 1) fresh vegetables, followed by 2) seafood, 3) lean meats, 4 ) fresh fruits, 5) whole milk, 6) whole grains, and 7) nuts and seeds.

To even suggest that milk is a good source of vitamin D is a total stretch of the facts. In 2010 the official Institute of Medicine daily recommended intake for vitamin D increased from 400 IU to 600 IU per day for most people (32). Although this advice represents a substantial raise, it still falls far short of human experimental evidence showing that at least 800 to 2,000 IU per day is required to keep blood levels of vitamin D at the ideal concentration of 50 ng/ml.13, 14, 129, 130 An eight oz glass of raw milk (280 calories) straight from the cow without fortification gives you a paltry 3.6 IU of vitamin D (76, 128). At this rate, you’d have to drink a ridiculous 167 eight oz glasses of milk just to achieve the 600 IU daily recommendation. Because most of the milk we drink is fortified with vitamin D, then an 8 oz glass typically yields 100 IU of this nutrient.128 However, even with fortification, you would have to drink six 8 oz glasses (1,680 calories or ~ 75 % of your daily caloric intake) of whole milk to meet the daily requirement for vitamin D. If you wanted to reach the 2,000 IU level as suggested by the world’s best vitamin D researchers,13, 14, 129, 130 you would have to drink 20 eight oz glasses of fortified whole milk amounting to 5,600 calories. No one in their right mind would drink 20 glasses of milk a day, even if they could. As you can see from these simple calculations, whether fortified or raw, milk is an abysmal source of vitamin D. The best way to get your vitamin D is not by drinking milk, but rather by getting a little daily sun exposure as nature intended.131, 132

Milk, Dairy and Heart Disease: The Early Days

The history of modern medicine is full of starts, stops, and reversals in strategy for treating disease. One of the more remarkable tales in recent medical history involves peptic ulcers. This is a chronic condition in which the linings of the stomach or small intestine are eroded away causing painful internal wounds. Complications include bleeding and perforation of the gastrointestinal tract, which are potentially life threatening.

For the better half of my adult life, peptic ulcers were routinely attributed to excessive stomach acid production caused mainly by stress, or spicy foods or too much gum chewing. Even as recently as the mid 1980’s, ulcer patients were advised to take antacids, make lifestyle changes to reduce stress, cut back on spicy foods and stop chewing gum. However, as we will soon see, this advice didn’t do much to alleviate symptoms or cure the problem.

One of the more unusual ideas that surfaced to treat peptic ulcers came from an early 20th century physician, Betram Sippy (M.D.). Dr. Sippy authored an influential paper that appeared in the Journal of the American Medical Association in 1915 suggesting that peptic ulcers could be effectively treated by feeding patients milk and cream on a regular basis throughout the day.112 The good doctor’s advice became known as the “Sippy Diet” and was employed widely across the United States to care for patients with ulcers even as recently as 25-30 years ago.127

One of the downsides to the Sippy Diet, first recognized in 1960 by Dr. Hartroft and colleagues at Washington University in Saint Louis was that it noticeably increased fatal heart attacks in ulcer patients.17, 52 In Dr. Hartroft’s study three groups were examined at autopsy: 1) subjects with peptic ulcers who followed the Sippy Diet, 2) subjects with peptic ulcers who didn’t follow the Sippy Diet, and 3) subjects without peptic ulcers. The fatal heart attack rate was similar between subjects without peptic ulcers and those with peptic ulcers who hadn’t been on the Sippy Diet. However, the fatal heart attack rate in ulcer patients who had adhered to the Sippy Diet was a staggering 42%. Think about these statistics. Close to half of all ulcer patients following the Sippy Diet had succumbed from heart attacks! Thank goodness to us all that the medical community no longer recommends the Sippy Diet for peptic ulcers.

The reason that physicians no longer recommend the Sippy Diet or any other dietary regime for the treatment of ulcers is one of the most incredible and unlikely tales in all of modern medicine. For almost 100 years, peptic ulcers were looked upon as a disease of excessive stomach acid production caused by stress, spicy food – whatever. No one ever considered that this condition might be caused by an infectious organism. That is, until the publication of two revolutionary papers in 1983 and 1984 by two Australian scientists, Barry Marshall and Robin Warren, showing that 70 to 90 % of peptic ulcers resulted from infection by the bacterium Helicobacter pylori.74, 75 At first, these innovative publications were generally dismissed and discredited by the medical community. However, it didn’t take long for practicing physicians to realize that ulcers could be effectively cured simply by giving their patients a good dose of antibiotics. Unfortunately, it took about a decade for these brilliant scientists’ ideas to be accepted worldwide. Now, because of their ground-breaking insights, antibiotics are routinely used to successfully treat and cure almost all peptic ulcer cases. In 2005 Drs. Marshall and Warren were awarded the Nobel Prize in medicine for their discoveries.133

A forgotten piece of the peptic ulcer story is that milk and dairy consumption significantly increased the risk for cardiovascular disease and heart attacks. The information about Sippy Diets and heart attack risk has been buried in the scientific literature for nearly 50 years and is virtually lost to contemporary scientists. OK. Fair enough. I would no longer necessarily hang my hat upon 50 year old studies than I would drink a cup of milk. However, the knowledge, wisdom and insight of our parent’s, grandparent’s and great grandparent’s generations shouldn’t just be swept under the rug. Is it possible that they were actually on to something?

Milk, Dairy and Heart Disease: Contemporary Science

The data from the early 1960’s studies on milk and heart attacks certainly bear further scrutiny. As we move forward from the past, numerous studies support the view that milk and dairy products may not be heart healthy and “Good for everybody”. A 1993 epidemiological study by Drs. Artaud-Wild and co-workers involving 40 countries worldwide demonstrated that milk and its components (calcium, protein and fat) had the highest relationship with cardiovascular death rates for any food or nutrient examined.7 Similar results implicating milk consumption with high mortality from heart disease were reported by Drs. Renaud and De Lorgeril in 1989,100 by Dr. Appleby and co-workers in 1999,8 by Dr. Segall,107, 108 and by Drs. Moss and Freed in 2003.78 Epidemiological studies are notorious for conflicting results. Here’s a perfect example. In a recent 2011 meta analysis,114 scientists at the Harvard School of Public Health showed that dairy food didn’t affect heart disease risk one way or another. Milk and dairy didn’t make things worse for our cardiovascular systems, but they also didn’t make them any better.114

Good scientists almost always let you know the weak points and shortcomings of their experiments because these limitations are an integral part of the scientific method which allows us all to glimpse the “truth”. The authors of this Harvard study expressed an important concern about the validity and generalizability of their experiment that you need to know. These kinds of details often get swept under the rug as milk industry lobbyists promote their products, and as governmental agencies make dietary recommendations. Let me quote the scientists who conducted this analysis:

“Conclusions from this meta-analysis only apply to the small proportion of analyzable study populations included in this work, within milk intakes of ~200-600 ml/d. Moreover, the internal validity of the different studies included in the meta-analysis (e.g., methodology and confounding factors) also determines the quality of the present meta-analysis.”

For those of you that may not completely understand this scientific admission, here’s what it means. The amount of milk in this analysis only ranged from 200 to 600 ml. This total represents a modest quantity which translates to only one to three 8 ounce glasses of milk per day. In other words the amount of milk in this study was too low to know if higher milk intakes increase heart disease risk. If we go back to the 1960s study of ulcer patients following the Sippy diet, they drank two to three times this much milk, and nearly 42 % died from heart attacks.17, 52

Milk is a lot like a moving target with more than one bull’s-eye. Scientists aren’t completely sure which element or elements may underlie its adverse effects upon our cardiovascular systems.30, 37, 73 Milk simply isn’t just a creamy white liquid that is “Good for everybody” but rather is a complex mixture of many substances suspected of causing heart disease including its high calcium content, fatty acids, lactose and certain proteins. Because milk contains so many compounds that could potentially promote heart disease, it is difficult or impossible for epidemiological studies to sort out all the facts. Let’s take a closer look at some specific elements in milk which may promote heart disease.

Decomposing Milk and Heart Disease

Unless you haven’t watched TV or read a newspaper or magazine in the past 20 years, most people know that milk and dairy products are one of our best sources of calcium. The dairy manufacturing industry has pounded this message into our brains for decades – so much so that many women fear they will develop osteoporosis if they don’t consume dairy foods. Until just recently, the prevailing knowledge was that if a little calcium was good for us, then more certainly must be even better. Not necessarily so. If we look at the evolutionary evidence, it becomes immediately clear that it would be virtually impossible to achieve governmental recommended calcium intakes without eating dairy products. In 2002, I wrote a scientific paper covering this topic, and my analysis showed that modern day Paleo Diets provide us with only about 70% of the daily recommended calcium intake.23 Given this evolutionary clue, then it is not be surprising to find that the supra-normal intakes of calcium that can be achieved by milk and dairy consumption may just cause unexpected health problems.

A recent 2010 meta analysis published in the British Journal of Medicine by Dr. Bolland and colleagues from the University of Auckland confirmed the health hazards of too much calcium. Their comprehensive analysis involving 26 separate studies and more than 20,000 subjects revealed that calcium supplementation significantly increased the risk for heart attacks and sudden death.16 High blood levels of calcium are likely involved in the artery clogging process (atherosclerosis)99 because too much calcium may promote the formation and fragility of the plaques which block our arteries.134

Interestingly, high dietary calcium also tends to cause imbalances in magnesium5, 34, 110 and this mineral is generally protective against heart disease for many reasons. As far back as 1974, Dr. Varo at the University of Finland pointed out that high dietary calcium to magnesium ratios were a better predictor of heart disease than high calcium intake alone.120 Meaning – that if you got too much calcium and not enough magnesium in your diet, it puts you at an increased risk for heart disease. Because milk’s calcium to magnesium ratio is quite high (about 12:1),128 the inclusion of dairy products in our diets can easily raise the overall calcium: magnesium ratio to about 5:1,120 thereby reducing cellular magnesium stores and promoting heart disease. Note that our studies of contemporary “Paleo”diets confirm that the dietary calcium to magnesium ratio was much lower and close to 2:1.23

Supplementation studies of magnesium show that it reduces heart disease risk via multiple mechanisms. It improves blood lipid profiles,47, 97 prevents heart beat irregularities called arrhythmias,57 improves insulin metabolism,82 and lowers markers of inflammation.82 If you decide to consume dairy products, you effectively negate these therapeutic effects of magnesium either fully or in part. If milk’s high calcium and low magnesium ratio was not bad enough, let’s consider just a few other nutritional features in milk which further promote heart disease.

In the 1950’s and early 1960’s when nutritional researchers were just beginning to understand how atherosclerosis and heart attacks developed, it was assumed to be a simple plumbing problem. Eat too much saturated fat and cholesterol, and your total blood cholesterol levels skyrocketed which clogged your arteries thereby predisposing you to a heart attack or stroke. Unfortunately, these simplistic views did not standup well to the test of time, as hundreds of studies starting in the late 1980s showed beyond a shadow of a doubt that inflammation and immune reactions were just as important or more so in the artery clogging process (atherosclerosis) than either consumption of saturated fat or cholesterol.79, 84, 135, 136

So this brings us to a larger question. What elements in diet may be responsible for causing chronic low level inflammation now known to underlie not just heart disease, but also cancer and autoimmune disease? The evolutionary template once again brings us back to foods which we never consumed in our ancestral past. Is there any possibility that these Johnnie- come-lately foods such as, milk and dairy, grains and legumes may cause chronic low level inflammation and promote immune responses that lead to heart disease?

Milk is an incredible amalgamation of nutrients, proteins and hormones that have only recently been discovered and appreciated. It certainly is not the pure white liquid, high in calcium, vitamin D and other vitamins and minerals portrayed by milk manufacturers and their lobbyists. You may not know it, but milk is essentially nothing more than filtered cow’s blood. As such, it contains almost all of the hormones, immunological factors, and body altering proteins that are found in pure cow blood.11, 64, 65 However, let’s don’t get too alarmed at this information. Most of these compounds in milk have very short half-lives and are spontaneously degraded within minutes or hours after the manufacture of modern dairy foods. Consequently, they should not enter our bloodstreams. Further, a healthy human gut lining rarely allows intact, large proteins such as those found in milk hormones to bypass its protective barrier. So why should we worry? Are there proteins or hormones in cow milk which bypass the gut barrier and eventually get into our bloodstreams to wreak havoc with our immune systems and promote atherosclerosis?

Milk, Insulin Resistance and the Metabolic Syndrome

I’ve briefly touched upon the glycemic index, but let me get into a bit more detail about how this indicator of a food’s blood sugar response relates to milk and dairy. As many of you may already know, the glycemic index gauges how much a food raises our blood glucose concentrations. Processed foods such as white bread, candies, breakfast cereals, cookies and even potatoes have high glycemic indices because they cause rapid and marked increases in our blood glucose levels.38 As such, these foods tend to promote the Metabolic Syndrome which includes diseases of insulin resistance such as type 2 diabetes, hypertension, cardiovascular disease, obesity, gout and detrimental blood chemistry profiles.24, 31, 117 Real foods such as lean meats, fish, eggs, fresh fruits and veggies typically have moderate to low glycemic indices and are not associated with the Metabolic Syndrome.24

Normally, when our blood sugar levels soar after we consume high glycemic index carbohydrates, our blood insulin concentrations also rise in tandem. This is the usual response. Shortly after the glycemic index was developed in the early 1980’s, it was discovered that milk, yogurt and most dairy foods had low glycemic responses.38 Presumably, these foods should be healthy and help to prevent the Metabolic Syndrome. However, about 5-10 years ago experiments from our laboratory and others unexpectedly revealed that low glycemic dairy foods paradoxically caused huge rises in blood insulin levels,42, 55, 59, 87 even when milk is added to mixed meals.70 The table below shows that despite their low glycemic indices, dairy foods maintain high insulin responses similar to white bread.

High Insulin Response | The Paleo Diet

This information posed a challenge to nutritional scientists. It was unclear if milk’s insulin stimulating effect but low glycemic response was healthful or harmful. To date only one human study conducted in 2005 has addressed this question. Dr. Hoppe and colleagues at The Royal Veterinary and Agricultural University in Denmark put 24 eight year old boys on either a high milk or high meat diet for seven days. The high milk diet worsened the boys’ insulin response nearly 100 %, and the entire group became insulin resistant in just a week’s time. In contrast, the high meat eating group’s insulin levels did not change, and their overall insulin metabolism remained healthy.58 The results of this experiment are alarming, particularly if future studies also demonstrate this effect in teenagers and adults. As insulin resistance is the fundamental metabolic defect underlying the Metabolic Syndrome, it would not be surprising to discover that milk drinking may cause other diseases of insulin resistance.

Milk and Acne

Until 2002 the official party line of the mainstream dermatology community was that diet had nothing to do with acne.22, 25 This viewpoint was expressed time and again in all of the major dermatology textbooks and became the doctrine taught to newly minted dermatologists. If you didn’t know any better, you might think that this perspective was based upon hundreds or even thousands of carefully controlled scientific studies. When I first started to examine the link between diet and acne more than 10 years ago, this is exactly what I had expected. How wrong I was! As it turned out, the dogma that diet didn’t cause acne was based solely upon two poorly conceived experiments conducted in 1969 and 1971.25 In a series of papers from 2002 to 2006, I pointed out this flawed assumption to the dermatology community.22, 25, 26

My research rekindled the entire diet/acne debate, but more importantly we showed that acne was completely absent in two non-westernized populations who didn’t drink milk or eat processed foods.22 We suspected that both milk and foods with high glycemic indices caused blood insulin levels to rise steeply and remain high all day long. In turn, elevated insulin levels set off a hormonal cascade that triggered the known cellular events which caused acne.22, 25 My hypothesis that milk, in part, caused acne was verified by a series of epidemiological studies from scientists at the Harvard School of Public Health.1-3 Even more convincing was an experimental study carried out by Dr. Neil Mann and colleagues at the Royal Melbourne Institute of Technology showing that low glycemic index, high protein diets improved acne symptoms113 as did a more recent randomized controlled trial by Kwon and co-workers.138

As it has been less than 12 years since my study in The Archives of Dermatology (2002) revived the diet/acne debate, scientists worldwide have not completely worked out how milk drinking promotes acne. Some researchers share our view that milk’s exaggerated insulin response along with high glycemic index carbohydrates sets off a hormonal cascade that causes acne.137 Others suggest that hormones found in cow milk may be responsible,1-3, 139 whereas some scientists believe that both mechanisms or perhaps others are involved.140

Hormones in Milk

Milk may be advertised as a squeaky clean white liquid, high in vitamin D and calcium, but if the truth be known, it is filtered cow’s blood and as such contains almost all of the hormones and bioactive peptides (protein building blocks) found in blood itself.10, 11, 33, 36, 39, 40, 51, 64, 65, 91, 92, 95, 96, 111 Take a look at the table below (which is only a partial listing), and you can see the incredible profusion of biologically active substances found in milk.

Growth Hormones

Insulin, Insulin like growth factor 1 (IGF-1), Insulin like growth factor 2 (IGF-2)
Insulin like growth factor binding proteins, 1 to 6 (IGFBP-1, 2, 3, 4, 5, 6),
Betacellulin (BTC), Growth hormone (GH), Growth hormone releasing factor (GHRF), Transforming growth factor alpha (TGF α), Transforming growth factor beta 1 (TGF-β1), (TGF-β2), Platelet derived growth factor (PDGF)

Steroid Hormones

Estrogens (Estrone, Estradiol-17β, Estriol and Estrone sulfate), Progesterone, 20 alpha-dihydropregnenolone, 5α androstanedione, 5 α pregnanedione, 20α- and 20β-dihydroprogesterone, 5α-pregnan-3β-ol-20-one, 5α-androstene-3β17β-diol, 5α-androstan-3β-ol-17-one, androstenedione, testosterone, and DHEA acyl ester

Bioactive Proteins and Peptides

Relaxin, Thyrotropin releasing hormone (TRH), Luteinizing hormone releasing hormone (LHRH), Somatostatin (SIH), Gastrin releasing peptide (GRP), Calcitonin, Adrenocorticotropic hormone (ACTH), Prolactin, Thyroid stimulating hormone (TSH), Lysozyme, Lactoperoxidase, Lactoferrin, Transferrin, Immunoglobulins (IgA, IgM, IgG), Proteose-peptone, Glycomacropeptide, Plasmin, α Casein, β Casein, κ Casein, α Lactoglobulin, β Lactoglobulin, Bovine serum albumen (BSA), Gastric inhibitory polypeptide (GIP), Glucagon-like peptide-1 (GLP-1), Antitrypsin, Plasminogen activator inhibitor-1, α(2) antiplasmin , Butyrophilin, Xanthine oxidase, Mucin-1, Mucin-15, Adipohilin, Fatty acid binding protein, CD36, Periodic acid Schiff 6/7

Bioactive Peptides formed in gut from Milk Proteins

Casomorphins, α Lactorphin, β Lactorphin, Lactoferroxins, Casoxins, Casokinins, Casoplatelins, Immunopeptides, Phosphopeptides.

The trick for any of these elements to wreak havoc with our health and wellbeing is for them to end up fully intact and present in our bloodstreams. To accomplish this feat, these hormones, proteins and peptides must first survive pasteurization (the quick heating of milk to destroy microorganisms), homogenization and other processing procedures applied to dairy foods. Next they must survive the digestion process and resist breakdown by our gut enzymes. Finally, they must cross the intestinal barrier which normally blocks entry of whole proteins, hormones and large peptides into our bloodstreams. As unlikely as this series of events may first appear, it now seems quite probable that cow hormones in milk indeed enter our bloodstream, particularly if we have a leaky gut.

For a young suckling calf, it is a good thing for its mother’s hormones, peptides and immune factors to cross the intestinal barrier. This process assures the calf will get a healthy start in life, grow rapidly and develop resistance to disease. To insure that mother’s hormones and peptides are not degraded in the calf’s gut by various enzymes, milk contains substances called protease inhibitors which prevent this breakdown.91, 96, 141 The downside of milk’s protease inhibitors is that they also prevent our own gut enzymes from destroying cow hormones and peptides. So the stage is set. Many hormones and bioactive peptides in milk survive pasteurization and food processing. They also resist enzymatic breakdown in our guts because inherent compounds in milk protect them. Ultimately, in order to adversely affect our health, these substances must then bypass the gut barrier and enter our bloodstream.

It is apparent that this final hurdle is routinely overcome because so many people have allergies and immune reactions to milk and its various protein components.21, 29, 54, 61, 72, 85, 86, 118, 119, 142, 143 When intact hormones, proteins or peptides cross the intestinal barrier, the immune system takes immediate steps to neutralize or destroy any particle that is perceived as a foreign invader. Part of this process is to form antibodies against milk proteins which later may be involved in allergic and autoimmune reactions. Many of the proteins and substances I have listed in the table above show up as specific milk allergens. Meaning – that they had to either cross the gut barrier and interact with the immune system or via another body interface.

Unsafe Milk Hormones

Of all the milk hormones and bioactive peptides I have listed in the table above, very few have been examined directly in human experiments. Nonetheless, evidence from animal, tissue and epidemiological studies suggest that consumption of cow, goat or sheep milk by humans and the subsequent ingestion of hormones and bioactive substancs at best may be unwise and at worst may be responsible for a number of life threatening diseases. Let’s take a look at the most problematic of these hormones.


The regular, everyday milk you buy at the supermarket is loaded with bovine insulin.51, 64, 65 This cow hormone not only survives your gut’s digestive enzymes, but it seems to frequently cross the gut barrier and make its way into the bloodstream, as revealed by telltale signs from our immune systems.72, 118, 119 Because the structure of bovine insulin varies from the human form, if it enters circulation, it is immediately recognized as a foreign particle and flagged as such by the immune system. The large number of children who display immune system flags (antibodies) to bovine insulin means that it has likely crossed the gut barrier intact and has caused an immune reaction. Although the mechanism is not entirely clear, the presence of bovine insulin antibodies in our children’s bloodstreams is associated with a greatly increased risk for Type 1 diabetes.72, 118, 119

Type 1 diabetes is an autoimmune disease in which the immune system destroys beta cells in the pancreas, so that it can no longer make insulin. Type 1 diabetic patients then must take insulin injections for the remainder of their lives. This devastating disease most frequently strikes children before their teen years. Epidemiological studies have time and again identified cow’s milk as a major risk factor for the disease, particularly if children are exposed to milk or milk containing formula before the age of three.66, 69, 72, 118, 119, 121 The bottom line: milk is a potentially lethal toxin for infants and young children, but also for adults as you shall soon see.

Insulin like Growth Factor 1 (IGF-1)

Another hormone found in cow’s milk that may have disastrous effects upon our health and wellbeing is called insulin like growth factor 1 (IGF-1). As implied from its name, this hormone encourages growth. Unfortunately it not only promotes growth in healthy tissues and organs, but also in cancerous growths.104, 115 Like all milk hormones, IGF-1 is a large protein molecule that normally should not breach the gut barrier and get into our bloodstreams. Nevertheless, recent meta analyses of 15 epidemiological studies and 8 human dietary interventions by Dr. Qin and colleagues at Soochow University have shown without a doubt that milk drinking robustly elevates IGF-1 in our bloodstreams.92 This effect may occur directly from the additional ingested bovine IGF-1 that crosses our gut barriers, or via indirect mechanisms. You recall that milk drinking causes our blood insulin levels to rise sharply. Whenever blood insulin concentrations increase, a series of connected hormonal events simultaneously cause IGF-1 to increase. Over a 24 hour period, blood insulin concentrations are a good marker for IGF-1 concentrations. When one increases so does the other.144

Whether IGF-1 in our blood is increased either directly from ingested bovine IGF-1 or indirectly from milk’s insulin raising effects doesn’t really matter, as the end result is the same – milk raises our total blood levels of IGF-1 (92). This particular consequence of milk drinking is especially ominous because it encourages the growth of many types of cancer. Numerous worldwide, meta analyses over the past 40 years show beyond a shadow of a doubt that high blood levels of IGF-1 strongly increase the risk for prostate and breast cancer.104, 115 If this outcome doesn’t alarm you, perhaps additional meta analyses will. These comprehensive studies show that milk drinking also increases the risk for ovarian cancer in women.44, 68 If you or any close relatives have a history of cancer, one of the best lifestyle changes you can make to reduce your risk of these life threatening diseases is to wipe your upper lip clean of the milk mustache and get milk and dairy completely out of your life!


By now you can see that milk isn’t simply an innocuous high calcium food that builds strong bones, but rather is a concoction of body altering hormones, enzymes and proactive peptides whose wide ranging effects may promote cardiovascular disease, insulin resistance, cancers, allergy and autoimmune diseases. Another hormone in milk which may operate in tandem with other bovine hormones, proteins and peptides to promote cancer is estrogen. It is present in bovine milk in a variety of forms including estrone, estradiol-17β, estriol, estrone sulfate and progesterone.36, 40, 95

Before we go any further, you need to know how modern dairy farmers maximize milk production from their cows. Dairy farmers are in the business to make money, and the more milk they can get from a single cow in a year, the more money they make. Female cows, like all mammals only produce milk during the latter half of pregnancy and during the suckling period. So the trick for modern dairy farmers is to get cows to make high amounts of milk during the early months of pregnancy when milk is normally not produced. Dairy farmers achieve this goal by artificially inseminating cows within three months after they have just given birth. In effect, these cows become pregnant once again while they are still nursing the young of their previous birth. This contrived interference by humans causes the mother cow to produce milk 305 days out of the year. From an economic perspective, this strategy makes perfect sense – more milk means more money. From a dietary and health perspective, this practice may increase the estrogen content in the milk we drink.36, 40, 95 For men, milk drinking (whether be it from added estrogen or other mechanisms) greatly increases your risk for prostate cancer.43, 67, 93, 94, 103, 126


So far we have only closely examined three hormones found in milk. You can see from my table that we have barely touched the tip of the iceberg. Because most of these substances have been so infrequently studied in humans, we simply don’t know how they may influence our health and wellbeing. Nevertheless, at least one additional hormone in milk called betacellulin is worth examining.

Betacellulin was only recently identified in cow milk in 1999 (33). It survives pasteurization and occurs in milk, cheese and whey proteins.10 Tissue studies of a molecularly similar hormone (EGF) demonstrate that it likely survives our digestive enzymes.96 A low ph, such as may be found in the gut, does not impair or prevent BTC from binding its receptor.146 Further betacellulin doesn’t have to worry about getting past the gut barrier. It gains easy access to our bloodstream by binding a structure in the gut lining called the epidermal growth factor receptor (EGF-R).26, 56, 90, 145 This structure is found throughout most cells in our body, and when the EGF-R becomes over stimulated, it is intimately associated with the development and progression of almost all types of cancers.53, 81 Tissue experiments show that betacellulin powerfully stimulates the EGF-R – more so than any other hormone.<sup<145 Further, pharmaceuticals which block EGF-R stimulation act as powerful anti-cancer agents in humans and animals.28, 46, 81, 83, 88, 109

It will take many more experiments and years of research to conclusively show whether or not the betacellulin in milk contributes to the cancers associated with milk drinking and dairy consumption. But you don’t have to wait that long. By eliminating milk and dairy products from your diet, you will immediately reduce your risk of these cancers, as well as allergy, heart disease, and autoimmune disease.

Milk and Dairy: More Health Problems

The list of adverse health effects known to arise from milk drinking is seemingly endless. Let me briefly point out some additional conditions and illnesses in which milk and dairy products have been implicated.

Food Allergies

The table below lists the eight most common food allergies in the U.S. population.

Food Ranking | The Paleo Diet

These foods account for 90 % of all food allergies, and notice that milk tops this list.85 Milk is also the most common childhood food allergy, where it afflicts between 2-3% of children between the ages of 1 to 3. Symptoms include: stomach pain, diarrhea, skin rashes, hives, wheezing, infantile colic and anaphylactic shock which can be life threatening. By age 3 most (85-90%) children grow out of their milk allergy. So at first, this change appears to be a good thing, but the down side to childhood milk allergy is that it predisposes the child to other food allergies for the rest of their lives. A study by Dr. Høst at the University of Southern Denmark54 alarmingly revealed that 50% of all infants and young children who were allergic to milk later developed allergies to a wide variety of other foods before puberty. As was the case with Type 1 diabetes, early exposure to milk proteins is the key to whether or not your child will develop allergies. The crucial period for restricting cow’s milk is from birth until at least age 2 or 3.

One of the more interesting disorders related to milk allergy is infantile colic. If you are planning on having children, or know someone who is, you may want to bookmark this paragraph. When a healthy baby cries, screams or fusses intensely for more than three hours a day, three days a week, it probably has colic. Continual infant crying is considerably more than just a parental annoyance. Crying and its associated exhaustion to parents and infants may cause serious problems including stress to your marriage, breastfeeding failure, and shaken baby syndrome, which frequently results in infant death.

Today it is almost universally recognized by pediatricians that infants should never consume milk (except mother’s milk) or dairy products until at least age one or beyond. A series of human infant experiments carried out in the 1980’s revealed beyond a shadow of a doubt that whey proteins in milk were largely responsible for colic. A powerful experiment known as a double blind crossover conducted by Drs. Lothe and Lindberg at the University of Lund in Sweden71 demonstrated that colic symptoms disappeared in 89% of all infants when they were given a cow milk free diet.

OK, this is good news, but you may ask why this information is relevant in 2014 when cow milk is no longer recommend by pediatricians until after about 1 year of age for infants. An often forgotten, but important offshoot of these 1980’s double blind crossover experiments was that they were also repeated in milk drinking mothers who breastfed their infants. Not surprisingly, infants who’s Moms drank milk became colicky, indicating that certain elements in cow’s milk may have caused an immunological response in the nursing mothers that was transferred to their milk which in turn was transmitted to their babies, making them cry.21, 61 Any food that causes such distress in infants should be a warning to us. It may be possible that our babies are more in tune with their bodies than we are.

Excessive Mucus Production

Too much milk consumption has long been associated with increased mucus production in the respiratory tract and incidence of asthma. I have a memory a few years back of going to a high school cross country meet and watching these young athletes cross the finish line. I noticed a few runners were literally “foaming at their mouths” because they had so much mucus being produced from their respiratory system. I wondered if milk drinking had anything to do with it, but at the time, the science hadn’t yet caught up with my observation and those of others. An intriguing new (2010) hypothesis by Drs. Bartley and McGlashan, otolaryngologists from New Zealand9 may have found the answer.

Go back to my table of all the hormones and bioactive substances found in milk. You will notice under the category, “Bioactive Peptides formed in gut from Milk Proteins”, a substance called casomorphins. These compounds are produced in our guts from the breakdown of the milk protein, casein. One of these casomorphins, beta-casomorphin-7 directly stimulates mucus production from specific glands (MUC5AC) located in the gut. If the gut becomes leaky, which it invariably does on a typical western diet, beta-casomorhin-7 can then enter our bloodstream and travel to our chests where it stimulates mucus production from MUC5AC glands located in our lungs and respiratory tracts. A final piece of this puzzle is that beta-casomorphin-7 is much more likely to trigger mucous production if the lungs and respiratory tract are inflamed by asthma.

Parkinson’s Disease

Parkinson’s disease is a nervous system disorder that primarily affects areas of the brain controlling movement. Disease symptoms include tremors, stiffness and difficulty moving. You may best know this disease through its two most famous victims, Muhammad Ali and Michael J. Fox. Although the cause of Parkinson’s disease isn’t known, both genetic and environmental elements seem to be involved. Like autoimmune diseases it appears that environmental factors may be the most important triggers of this debilitating illness. When we talk about environmental origins of any chronic disease with an unknown cause, diet has got to be at the very top of our list. And the first items that we should examine are those foods which were not part of our ancestral human diet. So this line of thought leads us once again to milk and dairy products.

A comprehensive 2007 meta analysis by researchers at the Harvard School of Public Health has identified a high intake of dairy foods as a prominent risk factor for Parkinson’s disease.20, 89, 123 Men who consumed the highest quantities of dairy products had an 80% greater risk of developing the disease than men who ate the lowest amounts. These results are consistent with the Honolulu Heart Study examining 7,504 men who were followed for 30 years for the incidence of Parkinson’s Disease. There was a 2.3 times greater incidence of Parkinson’s Disease in the highest milk drinkers compared to those who abstained from milk.89

Currently, it is unknown how and why milk drinking increases the risk for this illness, but autoimmune mechanisms seem likely, particularly those directed at insulin.123 Other prominent and more studied autoimmune diseases associated with milk and dairy consumption are multiple sclerosis, rheumatoid arthritis and gastrointestinal diseases such as Crohn’s disease, ulcerative colitis and irritable bowel syndrome. When you adopt The Paleo Diet, you will reduce your risk for Parkinson’s disease and other conditions with autoimmune components because this lifetime nutritional plan eliminates milk and other foods associated with the development certain autoimmune diseases. In my new book, The Paleo Answer (John Wiley & Sons, 2012), I fully discuss how Paleo Diets may have therapeutic potential for autoimmune disease patients.

Milk and Senile Cataracts

Senile cataracts are cloudy opacities that form in the lens of the eyes as people age and can ultimately cause blindness. The bad news is that if you live long enough, you will probably develop cataracts. The good news is that you can probably forestall their appearance until very late in life by following The Paleo Diet. For people between 52 to 62 years of age, 42% develop cataracts. This percentage increases to 60% between ages 65 and 75, and rises further to 91% for people between 75 and 85 years of age.27 In the U.S. and other westernized countries, cataracts are treated by surgical removal, whereas left untreated they are the leading cause of blindness in older adults worldwide.

Milk drinking has a lot to do with cataract formation. In rats, pigs and guinea pigs scientists routinely produce cataracts in these animals, even before they reach old age, simply by feeding them high milk and lactose diets.98, 101, 124 As you recall, the main sugar in milk is lactose which is broken down into its two constituent sugars (glucose and galactose) by the gut enzyme, lactase. Numerous epidemiological studies show that lactose and galactose are involved in premature cataract formation.63, 77, 102 Due to the way cataracts form, we can probably never prevent them completely, but chances are good that if you adopt a dairy free diet, you can live most of your life, even into old age, without developing cataracts.

Milk Impairs Iron and Zinc Absorption

The table below lists the top 13 nutrients most lacking in the U.S. Diet.24

Nutrient Requirements | The Paleo Diet

Notice that zinc is number one. More than 73% of all people in the U.S. don’t get enough of this essential mineral. Iron is number six and about 40 % of the population is deficient in this nutrient. Milk and dairy products are lousy sources of both iron and zinc.24, 128 But to add insult to injury, the high concentration of calcium in cow’s milk strongly interferes with the absorption of both iron and zinc.19, 48 Meaning – if you were to add a slice of melted cheese to your barbequed burger, it would severely reduce the amount of iron and zinc you could absorb from the burger.

Both zinc and iron are crucial minerals for our health and wellbeing. Low iron stores are the most frequent cause of anemia, and in children and teens they can impair mental functioning. Pregnant women with iron deficiency are at greater risk for delivering pre-term babies, and low iron stores may adversely affect athletic performance and work ability. The list of health problems associated with zinc deficiency is seemingly endless, but includes: low sperm counts, reduced libido, reduced immune function, increased susceptibility to upper respiratory infections, acne, white spots on fingernails, rough skin, lack of sexual development, stretch marks, macular degeneration, reduced collagen and increased wrinkling. When you follow The Paleo Diet, you will be eating meat at almost every meal, and meat is one of the most highly absorbable sources of both zinc and iron.23

Milk and Dairy: Bone Health

One of the biggest selling points the milk manufacturers would like us to believe is that by drinking lots of milk we can reduce our risk of osteoporosis and future hip fractures. The foremost danger associated with osteoporosis is hip fracture in the elderly. Between 18 to 33% of all elderly people suffering hip fractures die within a year after breaking their hips. Not a pretty statistic. Although most people, including dairy lobbyists, believe that a low intake of calcium is a risk factor for hip and other bone fractures, if the truth be known, the data says, “It just isn’t so.”

A 2007 meta analysis of 170,000 women and 68,000 men from the Harvard School of Public Health reported that high calcium intakes had no therapeutic effect upon hip fractures,15 as did a similar meta anlysis of 39,500 men and women from Europe.62 In the Harvard study,15 a pooled analysis of five human experimental trials showed no benefit of calcium supplementation on non-vertebrae fractures, but rather showed that increased calcium intakes actually increased the risk for hip fracture.15 A follow-up 2010 meta analysis specifically examining milk consumption and hip fracture risk in 195,000 women and 75,000 men also showed that low milk intakes didn’t increase fracture risk, nor did a high intakes prevent it.12 These studies clearly show that we have been misled by the dairying manufacturers’ Milk Mustache and Got Milk Campaign. You may now be asking yourself, “If milk and dairy consumption don’t reduce my bone fracture risk, then why in the world should I consume these foods?” I have asked myself this very same question and cannot come up with a single reason to drink milk and eat dairy products.


Loren Cordain, Ph.D., Professor Emeritus


1. Adebamowo, C.A. Spiegelman D, Danby FW, Frazier AL, Willett WC, Holmes MD. High school dietary dairy intake and teenage acne. J Am Acad Dermatol; 52(2):207-14, 2005.

2. Adebamowo, C.A. Spiegelman D, Berkey CS, Danby FW, Rockett HH, Colditz GA, Willett WC, Holmes MD. Milk consumption and acne in adolescent girls. Dermatol Online J; 12(4):1, 2006.

3. Adebamowo CA, Spiegelman D, Berkey CS, Danby FW, Rockett HH, Colditz GA, Willett WC, Holmes MD. Milk consumption and acne in teenaged boys. J Am Acad Dermatol. 2008 May;58(5):787-93

4. Adly L, Hill D, Sherman ME, Sturgeon SR, Fears T, Mies C, Ziegler RG, Hoover RN, Schairer C. Serum concentrations of estrogens, sex hormone-binding globulin, and androgens and risk of breast cancer in postmenopausal women. Int J Cancer. 2006 Nov 15;119(10):2402-7.

5. Alcock N, Macintyre I. Inter-relation of calcium and magnesium absorption. Clin Sci. 1962 Apr;22:185-93.

6. Loftus RT, Ertugrul O, Harba AH, El-Barody MA, MacHugh DE, Park SD, Bradley DG. A microsatellite survey of cattle from a centre of origin: the Near East. Mol Ecol. 1999 Dec;8(12):2015-22.

7. Artaud-Wild S et al. Differences in coronary mortality can be explained by differences in cholesterol and saturated fat intake in 40 countries but not in France and Finland. Circulation 1993;88:2771-79.

8. Appleby PN, Thorogood M, Mann JI, Key TJ. The Oxford Vegetarian Study: an overview. Am J Clin Nutr. 1999 Sep;70(3 Suppl):525S-531S.

9. Bartley J, McGlashan SR.Does milk increase mucus production? Med Hypotheses. 2010 Apr;74(4):732-4.

10. Bastian SE, Dunbar AJ, Priebe IK, Owens PC, Goddard C. Measurement of betacellulin levels in bovine serum, colostrum and milk. J Endocrinol. 2001 Jan;168(1):203-12.

11. Belvedere P, Gabai G, Dalla VL, et al. Occurrence of steroidogenic enzymes in the bovine mammary gland at different functional stages. J Steroid Biochem Mol Biol 1996;59:339-47.

12. Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, Kanis JA, Orav EJ, Staehelin HB, Kiel DP, Burckhardt P, Henschkowski J, Spiegelman D, Li R, Wong JB, Feskanich D, Willett WC. Milk intake and risk of hip fracture in men and women: A meta-analysis of prospective cohort studies. J Bone Miner Res. 2010 Oct 14.

13. Bischoff-Ferrari HA, Shao A, Dawson-Hughes B, Hathcock J, Giovannucci E, Willett WC. Benefit-risk assessment of vitamin D supplementation. Osteoporos Int. 2010 Jul;21(7):1121-32.

14. Bischoff-Ferrari HA. Optimal serum 25-hydroxyvitamin D levels for multiple health outcomes. Adv Exp Med Biol. 2008;624:55-71

15. Bischoff-Ferrari HA, Dawson-Hughes B, Baron JA, et al. Calcium intake and hip fracture risk in men and women: a meta-analysis of prospective cohort studies and randomized controlled trials. Am J Clin Nutr 2007;86:1780-90.

16. Bolland MJ, Avenell A, Baron JA, Grey A, MacLennan GS, Gamble GD, Reid IR. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ. 2010 Jul 29;341:c3691

17. Briggs RD, Rubenberg ML, O’neal RM, Thomas WA, Hartroft WS. Myocardial infarction in patients treated with Sippy and other high-milk diets: an autopsy study of fifteen hospitals in the U.S.A. and Great Britain. Circulation. 1960 Apr;21:538-42.

18. Hiendleder S, Kaupe B, Wassmuth R, Janke A. Molecular analysis of wild and domestic sheep questions current nomenclature and provides evidence for domestication from two different subspecies. Proc Biol Sci. 2002 May 7;269(1494):893-904.

19. Castillo-Duran C, Solomons NW. Studies on the bioavailability of zinc in humans. IX. Interaction of beef-zinc with iron, calcium and lactose. Nutr Res 1991;11:429-38.

20. Chen H, O’Reilly E, McCullough ML, Rodriguez C, Schwarzschild MA, Calle EE, Thun MJ, Ascherio A. Consumption of dairy products and risk of Parkinson’s disease. Am J Epidemiol. 2007 May 1;165(9):998-1006.

21. Clyne, P.S., Kulczycki, A. Human breast milk contains bovine IgG. Relationship to Infant Colic? Pediatrics. 1992; 87: 439-444.

22. Cordain L, Lindeberg S, Hurtado M, Hill K, Eaton SB, Brand-Miller J. Acne vulgaris: a disease of Western civilization. Arch Dermatol. 2002 Dec;138(12):1584-90. //thepaleodiet.com/research-about-the-paleo-diet/#2002

23. Cordain L. The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Nutraceut Assoc 2002; 5:15-24. //thepaleodiet.com/research-about-the-paleo-diet/#2002

24. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005 Feb;81(2):341-54. //thepaleodiet.com/research-about-the-paleo-diet/#2005

25. Cordain L. Implications for the role of diet in acne. Semin Cutan Med Surg. 2005 Jun;24(2):84-91 //thepaleodiet.com/research-about-the-paleo-diet/#2005

26. Cordain L. Dietary implications for the development of acne: a shifting paradigm. In: U.S. Dermatology Review II 2006, (Ed.,Bedlow, J). Touch Briefings Publications, London, 2006. //thepaleodiet.com/research-about-the-paleo-diet/#2006

27. Couet C, Jan P, Debry G. Lactose and cataract in humans: a review. J Am Coll Nutr 1991;10:79-86.

28. Davies DE, Chamberlin SG. Targeting the epidermal growth factor receptor for therapy of carcinomas. Biochem Pharmacol. 1996 May 3;51(9):1101-10.

29. Davies DF, Davies JR, Richards MA. Antibodies to reconstituted dried cow’s milk protein in coronary heart disease. J Atherocler Res 1969;9:103-07.

30. Deeth HC. Homogenized milk and atherosclerotic disease: A review. J. Dairy Sci 1983;66:1419-35.

31. de Rougemont A, Normand S, Nazare JA, Skilton MR, Sothier M, Vinoy S, Laville M. Beneficial effects of a 5-week low-glycaemic index regimen on weight control and cardiovascular risk factors in overweight non-diabetic subjects. Br J Nutr. 2007 Dec;98(6):1288-98.

32. Dietary Reference Intakes for Calcium and Vitamin D. Institute of Medicine of the National Academies, 2010, //www.iom.edu/Reports/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D.aspx

33. Dunbar AJ, Priebe IK, Belford DA, Goddard C. Identification of betacellulin as a major peptide growth factor in milk: purification, characterization and molecular cloning of bovine betacellulin. Biochem J. 1999 Dec 15;344 Pt 3:713-21.

34. Evans GH et al. Association of magnesium deficiency with the blood pressure lowering effects of calcium. J Hypertension 1990;8:327-337.

35. Evershed RP, Payne S, Sherratt AG, Copley MS, Coolidge J, Urem-Kotsu D, et al. Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding. Nature. 2008 Sep 25;455(7212):528-31

36. Farlow DW, Xu X, Veenstra TD. Quantitative measurement of endogenous estrogen metabolites, risk-factors for development of breast cancer, in commercial milk products by LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci. 2009;877(13):1327-34.

37. Fields M, Lewis CG, Lure MD. Copper deficiency in rats: the effect of type of dietary protein. J Am Coll Nutr 1993;12:303-06.

38. Foster-Powell K, Holt SH, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr. 2002 Jul;76(1):5-56.

39. Ganmaa D, Wang PY, Qin LQ, Hoshi K, Sato A. Is milk responsible for male reproductive disorders? Med Hypotheses. 2001 Oct;57(4):510-4.

40. Ganmaa D, Sato A. The possible role of female sex hormones in milk from pregnant cows in the development of breast, ovarian and corpus uteri cancers. Med Hypotheses. 2005;65(6):1028-37.

41. Ganmaa D, Tezuka H, Enkhmaa D, Hoshi K, Sato A. Commercial cows’ milk has uterotrophic activity on the uteri of young ovariectomized rats and immature rats. Int J Cancer. 2006 May 1;118(9):2363-5

42. Gannon MC, Nuttall FQ, Krezowski PA, Billington CJ, Parker S. The serum insulin and plasma glucose responses to milk and fruit products in type 2 (non-insulin-dependent) diabetic patients. Diabetologia. 1986 Nov;29(11):784-91.

43. Gao X, LaValley MP, Tucker KL. Prospective studies of dairy product and calcium intakes and prostate cancer risk: a meta-analysis. J Natl Cancer Inst. 2005 Dec 7;97(23):1768-77.

44. Genkinger JM, Hunter DJ, Spiegelman D, et al. Dairy products and ovarian cancer: a pooled analysis of 12 cohort studies. Cancer Epidemiol Biomarkers Prev. 2006 Feb;15(2):364-72

45. Gerrior S, Bente I. 2002. Nutrient Content of the U.S. Food Supply, 1909-99: A Summary Report. U.S.D.A, Center for Nutrition Policy and Promotion. Home Economics Research Report No. 55

46. Gravis G, Bladou F, Salem N, Gonçalves A, Esterni B, Walz J, Bagattini S, Marcy M, Brunelle S, Viens P. Results from a monocentric phase II trial of erlotinib in patients with metastatic prostate cancer. Ann Oncol. 2008 Sep;19(9):1624-8

47. Gueux E, Cubizolles C, Bussière L, Mazur A, Rayssiguier Y. et al. Oxidative modification of triglyceride rich lipoprotein in hypertriglyceridemic rats following magnesium deficiency. Lipids 1993;28:573-75.

48. Hallberg L, Rossander-Hulten L, Brune M, Gleerup A. Calcium and iron absorption: mechanism of action and nutritional importance. Eur J Clin Nutr. 1992 May;46(5):317-27.

49. Hankinson SE, Eliassen AH. Endogenous estrogen, testosterone and progesterone levels in relation to breast cancer risk. J Steroid Biochem Mol Biol. 2007 Aug-Sep;106(1-5):24-30

50. Luikart G, Gielly L, Excoffier L, Vigne JD, Bouvet J, Taberlet P. Multiple maternal origins and weak phylogeographic structure in domestic goats. Proc Natl Acad Sci U S A. 2001 May 8;98(10):5927-32.

51. Hartmann S, Lacorn M, Steinhart H. Natural occurrence of steroid hormones in food. Food Chem 1998;6:7-20.

52. Hartroft WS. The incidence of coronary artery disease in patients treated with Sippy diet. Am J Clin Nutr. 1964 Oct;15:205-10

53. Henson ES, Gibson SB. Surviving cell death through epidermal growth factor (EGF) signal transduction pathways: Implications for cancer therapy. Cell Signal. 2006 Dec;18(12):2089-97.

54. Høst A. Frequency of cow’s milk allergy in childhood. Ann Allergy Asthma Immunol. 2002 Dec;89(6 Suppl 1):33-7.

55. Holt SH Miller JC, Petocz P. An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods. Am J Clin Nutr. 1997 Nov;66(5):1264-76

56. Hormi K, Lehy T. Developmental expression of transforming growth factor-alpha and epidermal growth factor receptor proteins in the human pancreas and digestive tract. Cell Tissue Res. 1994 Dec;278(3):439-50.

57. Horner SM et al. Efficacy of intravenous magnesium in acute myocardial infarction in reducing arrhythmias and mortality. Meta analysis of magnesium in acute myocardial infarction. Circulation 1992;86:774-79.

58. Hoppe C, Mølgaard C, Vaag A, Barkholt V, Michaelsen KF. High intakes of milk, but not meat increase s-insulin and insulin resistance in 8-year-old boys. Eur J Clin Nutr. 2005 Mar;59(3):393-8

59. Hoyt G, Hickey MS, Cordain, L. Dissociation of the glycaemic and insulinaemic responses to whole and skimmed milk. Br J Nutr. 2005 Feb;93(2):175-7

60. Ingram CJ, Mulcare CA, Itan Y, Thomas MG, Swallow DM. Lactose digestion and the evolutionary genetics of lactase persistence. Hum Genet. 2009 Jan;124(6):579-91

61. Jakobsson I, Lindberg T. Cow’s milk proteins cause infantile colic in breast-fed infants: a double-blind crossover study. Pediatrics. 1983 Feb;71(2):268-71.

62. Kanis JA, Johansson H, Oden A, De Laet C, Johnell O, Eisman JA, Mc Closkey E, Mellstrom D, Pols H, Reeve J, Silman A, Tenenhouse A. A meta-analysis of milk intake and fracture risk: low utility for case finding. Osteoporos Int. 2005 Jul;16(7):799-804.

63. Karas-Kuzelicki N, Pfeifer V, Lukac-Bajalo J. Synergistic effect of high lactase activity genotype and galactose-1-phosphate uridyl transferase (GALT) mutations on idiopathic presenile cataract formation. Clin Biochem. 2008 Jul;41(10-11):869-74.

64. Koldovský, O (1995) Hormones in milk. In Vitamins and Hormones 50, 77-149 [Litwack G, editor]. New York, Academic Press.

65. Koldovský, O. (1996) The potential physiological significance of milk-borne hormonally active substances for the neonate. J Mammary Gland Biol Neoplasia 1, 317-323.

66. Kostraba JN, Cruickshanks KJ, Lawler-Heavner J, Jobim LF, Rewers MJ, Gay EC, Chase HP, Klingensmith G, Hamman RF. Early exposure to cow’s milk and solid foods in infancy, genetic predisposition, and risk of IDDM. Diabetes. 1993 Feb;42(2):288-95.

67. Kurahashi N, Inoue M, Iwasaki M, et al. Dairy product, saturated fatty acid, and calcium intake and prostate cancer in a prospective cohort of Japanese men. Cancer Epidemiol Biomarkers Prev. 2008 Apr;17(4):930-7.

68. Larsson SC, Orsini N, Wolk A. Milk, milk products and lactose intake and ovarian cancer risk: a meta-analysis of epidemiological studies. Int J Cancer. 2006 Jan 15;118(2):431-41

69. Laugesen M, Elliott R. Ischaemic heart disease, Type 1 diabetes, and cow milk A1 beta-casein. N Z Med J. 2003 Jan 24;116(1168):U295.

70. Liljeberg Elmstahl H & Bjorck I. Milk as a supplement to mixed meals may elevate postprandial insulinaemia. Eur J Clin Nutr 2001; 55:994–999.

71. Lothe L, Lindberg T. Cow’s milk whey protein elicits symptoms of infantile colic in colicky formula-fed infants: a double-blind crossover study. Pediatrics. 1989 Feb;83(2):262-6.

72. Luopajärvi K, Savilahti E, Virtanen SM, Ilonen J, Knip M, Akerblom HK, Vaarala O. Enhanced levels of cow’s milk antibodies in infancy in children who develop type 1 diabetes later in childhood. Pediatr Diabetes. 2008 Oct;9(5):434-41.

73. Lynch SM , Strain JJ. Effects of copper deficiency on hepatic and cardiac antioxidant enzyme activities in lactose and sucrose fed rats. Brit J Nutr 1989;61:345-54.

74. Marshall B.J. (1983). Unidentified curved bacillus on gastric epithelium in active chronic gastritis. Lancet 1 (8336): 1273–5

75. Marshall B.J., Warren J.R. (1984). Unidentified curved bacilli in the stomach patients with gastritis and peptic ulceration. Lancet 1 (8390): 1311–5.

76. McDermott CM, Beitz DC, Littledike ET, Horst RL. Effects of dietary vitamin D3 on concentrations of vitamin D and its metabolites in blood plasma and milk of dairy cows. J Dairy Sci 1985;68:1959-67.

77. Meloni G, Ogana A, Mannazzu MC, Meloni T, Carta F, Carta A. High prevalence of lactose absorbers in patients with presenile cataract from northern Sardinia.Br J Ophthalmol. 1995 Jul;79(7):709.

78. Moss M, Freed D. The cow and the coronary: epidemiology, biochemistry and immunology. Int J Cardiol. 2003 Feb;87(2-3):203-16.

79. Munro JM, van der Walt JD, Munro CS, Chalmers JA, Cox EL. An immunolohistochemical analysis of human aortic fatty streaks. Hum Pathol 1987;18:375-80.

80. Cordain, L., Hickey, M. , Kim K. Malaria and rickets represent selective forces for the convergent evolution of adult lactase persistence. In: Biodiversity in Agriculture: Domestication, Evolution and Sustainability, Gepts P, Famula T, Bettinger R et al. (Eds.), Cambridge University Press, Cambridge, UK, 2011, pp 299-308. //thepaleodiet.com/research-about-the-paleo-diet/#2011

81. Muslimov GF. Role of epidermal growth factor gene in the development of pancreatic cancer and efficiency of inhibitors of this gene in the treatment of pancreatic carcinoma. Bull Exp Biol Med. 2008 Apr;145(4):535-8

82. Nadler JL Buchanan T, Natarajan R, Antonipillai I, Bergman R, Rude R. Magnesium deficiency produces insulin resistance and increased thromboxane synthesis. Hypertension 1993;21:1024-29.

83. Nanda R. Targeting the human epidermal growth factor receptor 2 (HER2) in the treatment of breast cancer: recent advances and future directions. Rev Recent Clin Trials. 2007 May;2(2):111-6

84. Napoli C, Ambrosio G, Palumbo G, Elia PP, Chiariello M. . Human low density lipoproteins are peroxidized by free radicals via chain reactions triggered by the superoxide radical. Cardiologica 1991;36:527-32.

85. National Institute of Allergy and Infectious Diseases (July 2004). “NIH Publication No. 04-5518: Food Allergy: An Overview.

86. Oski, FA. Don’t Drink Your Milk!: The Frightening New Medical Facts About the World’s Most Overrated Nutrient. Wyden Books, New York, 1977.

87. Ostman EM, Liljeberg Elmståhl HG, Björck IM. Inconsistency between glycemic and insulinemic responses to regular and fermented milk products. Am J Clin Nutr 2001;74:96 –100.

88. Palayekar MJ, Herzog TJ. The emerging role of epidermal growth factor receptor inhibitors in ovarian cancer. Int J Gynecol Cancer. 2008 Sep-Oct;18(5):879-90

89. Park M, Ross GW, Petrovitch H, White LR, Masaki KH, Nelson JS, Tanner CM, Curb JD, Blanchette PL, Abbott RD. Consumption of milk and calcium in midlife and the future risk of Parkinson disease. Neurology. 2005 Mar 22;64(6):1047-51

90. Montaner B, Perez-Tomas R. Epidermal growth factor receptor (EGF-R) localization in the apical membrane of the enterocytes of rat duodenum. Cell Biol Int. 1999;23(7):475-9.

91. Precetti AS, Oria MP, Nielsen SS. Presence in bovine milk of two protease inhibitors of the plasmin system. J Dairy Sci 1997;80: 1490-6.

92. Qin LQ, He K, Xu JY. Milk consumption and circulating insulin-like growth factor-I level: a systematic literature review. Int J Food Sci Nutr. 2009;60 Suppl 7:330-40.

93. Qin LQ, Xu JY, Wang PY, Tong J, Hoshi K. Milk consumption is a risk factor for prostate cancer in Western countries: evidence from cohort studies. Asia Pac J Clin Nutr. 2007;16(3):467-76.

94. Qin LQ, Xu JY, Wang PY, Kaneko T, Hoshi K, Sato A. Milk consumption is a risk factor for prostate cancer: meta-analysis of case-control studies. Nutr Cancer. 2004;48(1):22-7

95. Qin LQ, Wang PY, Kaneko T, Hoshi K, Sato A. Estrogen: one of the risk factors in milk for prostate cancer. Med Hypotheses. 2004;62(1):133-42.

96. Rao RK, Baker RD, Baker SS. Bovine milk inhibits proteolytic degradation of epidermal growth factor in human gastric and duodenal lumen. Peptides. 1998; 19(3):495-504

97. Rasmussen HS et al. Influence of magnesium substitution therapy on blood lipid composition in patients with ischemic heart disease. Arch Int Med 1989;149:1050-53.

98. Ratnakar KS. Interaction of galactose and dietary protein deficiency on rat lens. Opthalmic Res 1985;17:344-48.

99. Reid IR, Bolland MJ, Grey A. Does calcium supplementation increase cardiovascular risk? Clin Endocrinol (Oxf). 2010 Dec;73(6):689-95.

100. Renaud S, Lorgeril M. Dietary lipids and their relation to ischaemic heart disease: from epidemiology to prevention. J Int Med 1989;225 (supp 1):39-46.

101. Richter, CP, Duke, JR. Cataracts produced in rats by yogurt. Science 1970;168: 1372-74.

102. Rinaldi E, Albini L, Costagliola C, De Rosa G, Auricchio G, De Vizia B, Auricchio S. High frequency of lactose absorbers among adults with idiopathic senile and presenile cataract in a population with a high prevalence of primary adult lactose malabsorption. Lancet. 1984 Feb 18;1(8373):355-7

103. Rohrmann S, Platz EA, Kavanaugh CJ, et al. Meat and dairy consumption and subsequent risk of prostate cancer in a US cohort study. Cancer Causes Control. 2007 Feb;18(1):41-50.

104. Rowlands MA, Gunnell D, Harris R, Vatten LJ, Holly JM, Martin RM. Circulating insulin-like growth factor peptides and prostate cancer risk: a systematic review and meta-analysis. Int J Cancer. 2009 May 15;124(10):2416-29.

105. Santayana G. The Life of Reason or, The phases of Human Progress. C. Scribner’s Sons, New York, 1905.

106. Schairer C, Hill D, Sturgeon SR, Fears T, Mies C, Ziegler RG, Hoover RN, Sherman ME. Serum concentrations of estrogens, sex hormone binding globulin, and androgens and risk of breast hyperplasia in postmenopausal women. Cancer Epidemiol Biomarkers Prev. 2005 Jul;14(7):1660-5.

107. Segall JJ. Dietary lactose as a possible risk factor for ischeemic heart disease: review of epidemiology. Int J Cardiol 1994;46:197-207.

108. Segall JJ. Plausibility of dietary lactose as a coronary risk factor. J Nutr Environ Med 2002:12:217-229.

109. Seiwert TY, Cohen E. The emerging role of EGFR and VEGF inhibition in the treatment of head and neck squamous cell carcinoma. Angiogenesis Oncol 2005;1:7-10

110. Seelig MS. Increased need for magnesium with the use of combined oestrogen and calcium for osteoporosis treatment. Magnes Res. 1990 Sep;3(3):197-215.

111. Séverin S, Wenshui X. Milk biologically active components as nutraceuticals: review.
Crit Rev Food Sci Nutr. 2005;45(7-8):645-56

112. Sippy BW. Gastric and duodenal ulcer. Medical cure by an efficient removal of gastric juice corrosion. JAMA 1915;64:1625-30.

113. Smith RN, Mann NJ, Braue A, Mäkeläinen H, Varigos GA. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007 Jul;86(1):107-15.

114. Soedamah-Muthu SS, Ding EL, Al-Delaimy WK, Hu FB, Engberink MF, Willett WC, Geleijnse JM. Milk and dairy consumption and incidence of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies. Am J Clin Nutr. 2011 Jan;93(1):158-71.

115. Sugumar A, Liu YC, Xia Q, Koh YS, Matsuo K. Insulin-like growth factor (IGF)-I and IGF-binding protein 3 and the risk of premenopausal breast cancer: a meta-analysis of literature. Int J Cancer. 2004 Aug 20;111(2):293-7.

116. Swallow DM. 2003. Genetics of lactase persistence and lactose intolerance. Annual Review of Genetics 37:197-219.

117. Thomas DE, Elliott EJ, Baur L. Low glycaemic index or low glycaemic load diets for overweight and obesity. Cochrane Database Syst Rev. 2007 Jul 18;(3):CD005105

118. Vaarala O, Paronen J, Otonkoski T, A ° Kerblom HK. Cow milk feeding induces antibodies to insulin in children—a link between cow milk and insulin-dependent diabetes mellitus? Scand J Immunol 1998: 47: 131–135.

119. Vaarala O, Knip M, Paronen J et al. Cow’s milk formula feeding induces primary immunization to insulin in infants at genetic risk for type 1 diabetes. Diabetes 1999: 48: 1389–1394.

120. Varo P. Mineral element balance and coronary heart disease. Internat J Vit Nutr Res 1974;44:267-273.

121. Virtanen SM, Räsänen L, Ylönen K, Aro A, Clayton D, Langholz B, Pitkäniemi J, Savilahti E, Lounamaa R, Tuomilehto J, et al. Early introduction of dairy products associated with increased risk of IDDM in Finnish children. The Childhood in Diabetes in Finland Study Group. Diabetes. 1993 Dec;42(12):1786-90

122. Wang TK, Bolland MJ, van Pelt NC, Horne AM, Mason BH, Ames RW, Grey AB, Ruygrok PN, Gamble GD, Reid IR. Relationships between vascular calcification, calcium metabolism, bone density, and fractures. J Bone Miner Res. 2010 Dec;25(12):2501-9

123. Wilhelm KR, Yanamandra K, Gruden MA, Zamotin V, Malisauskas M, Casaite V, Darinskas A, Forsgren L, Morozova-Roche LA. Immune reactivity towards insulin, its amyloid and protein S100B in blood sera of Parkinson’s disease patients. Eur J Neurol. 2007 Mar;14(3):327-34.

124. Yudkin AM, Arnold CH. Cataracts produced in albino rats on a ration containing a high proportion of lactose or galactose. Trans Am Opthalmol Soc 1935;33:281-90.

125. Zhang J, Kesteloot H. Milk consumption in relation to incidence of prostate, breast, colon, and rectal cancers: is there an independent effect? Nutr Cancer. 2005;53(1):65-72

126. Zucker GM, Clayman CB. Landmark perspective: Bertram W. Sippy and ulcer disease therapy. JAMA. 1983 Oct 28;250(16):2198-202.

127. Nutritionist Pro Software. Axxya Systems. //www.nutritionistpro.com/

128. Bischoff-Ferrari HA, Willett WC, Orav EJ, Lips P, Meunier PJ, Lyons RA, Flicker L, Wark J, Jackson RD, Cauley JA, Meyer HE, Pfeifer M, Sanders KM, Stähelin HB, Theiler R, Dawson-Hughes B. A pooled analysis of vitamin D dose requirements for fracture prevention. N Engl J Med. 2012 Jul 5;367(1):40-9.

129. Brouwer-Brolsma EM1, Bischoff-Ferrari HA, Bouillon R, Feskens EJ, Gallagher CJ, Hypponen E, Llewellyn DJ, Stoecklin E, Dierkes J, Kies AK, Kok FJ, Lamberg-Allardt C, Moser U, Pilz S, Saris WH, van Schoor NM, Weber P, Witkamp R, Zittermann A, de Groot LC. Vitamin D: do we get enough? A discussion between vitamin D experts in order to make a step towards the harmonisation of dietary reference intakes for vitamin D across Europe. Osteoporos Int. 2013 May;24(5):1567-77.

130. Godar DE, Pope SJ, Grant WB, Holick MF. Solar UV doses of adult Americans and vitamin D(3) production. Dermatoendocrinol. 2011 Oct;3(4):243-50

131. Holick MF. Vitamin D: a d-lightful solution for health. J Investig Med. 2011 Aug;59(6):872-80

132. Fock KM, Graham DY, Malfertheiner P. Helicobacter pylori research: historical insights and future directions. Nat Rev Gastroenterol Hepatol. 2013 Aug;10(8):495-500.

133. Anderson JJ, Klemmer PJ. Risk of high dietary calcium for arterial calcification in older adults. Nutrients. 2013 Sep 30;5(10):3964-74.

134. Hansson GK. Inflammation, atherosclerosis, and coronary artery disease. N Engl J Med. 2005 Apr 21;352(16):1685-95.

135. Ross R. Atherosclerosis–an inflammatory disease. N Engl J Med. 1999 Jan 14;340(2):115-26.

136. Melnik BC1, John SM, Plewig G. Acne: risk indicator for increased body mass index and insulin resistance. Acta Derm Venereol. 2013 Nov;93(6):644-9. doi: 10.2340/00015555-1677.

137. Kwon HH, Yoon JY, Hong JS, Jung JY, Park MS, Suh DH.Clinical and histological effect of a low glycaemic load diet in treatment of acne vulgaris in Korean patients: a randomized, controlled trial. Acta Derm Venereol. 2012 May;92(3):241-6

138. Danby FW. Nutrition and acne. Clin Dermatol. 2010 Nov-Dec;28(6):598-604.

139. Bowe WP1, Joshi SS, Shalita AR. Diet and acne J Am Acad Dermatol. 2010 Jul;63(1):124-41.

140. Ismail B1, Nielsen SS. Invited review: Plasmin protease in milk: current knowledge and relevance to dairy industry. J Dairy Sci. 2010 Nov;93(11):4999-5009.

141. Arrar L, Hanachi N, Rouba K, Charef N, Khennouf S, Baghiani A. Anti-xanthine oxidase antibodies in sera and synovial fluid of patients with rheumatoid arthritis and other joint inflammations. Saudi Med J. 2008 Jun;29(6):803-7

142. Bruder G, Jarasch ED, Heid HW. High concentrations of antibodies to xanthine oxidase in human and animal sera. Molecular characterization. J Clin Invest. 1984 Sep;74(3):783-94.

143. Cordain L, Eades MR, Eades MD. Hyperinsulinemic diseases of civilization: more than just Syndrome X. Comp Biochem Physiol A Mol Integr Physiol. 2003 Sep;136(1):95-112.

144. Holbro T, Civenni G, Hynes NE. The ErbB receptors and their role in cancer progression. Exp Cell Res. 2003;284(1):99-110.

145. Bouyain S, Longo PA, Li S, Ferguson KM, Leahy DJ. The extracellular region of ErbB4 adopts a tethered conformation in the absence of ligand. Proc Natl Acad Sci U S A. 2005;102(42):15024-9.

Does Non-Allergenic Milk Exist? | The Paleo Diet

Dear Paleo Diet Team,

In the 1997 work entitled “Food and Low Incidence of Insulin Dependent Diabetes Mellitus (IDDM) in Iceland” (L. Thorsdottir and O. Reykdal) have suggested that the incidence of IDDM is lower in Iceland than in other human genetic related nations of Scandinavia.

Since milk proteins alleles frequencies in the Nordic cattle breeds varies and preliminary (at that time) results indicated that Beta Casein A1 was particularly low in Iceland milk, they have speculated that IDDM was caused by Beta Casein A1 and its bioactive peptide BCM-7.

My opinion is that Diabetes mellitus is not caused by one single factor alone, but perhaps there are also other factors involved.

I would like to know your opinion on that matter if possible, since cattle breeding association in Brazil, of a particular breed that produces A2 milk, is applying to official agencies to market their milk with the allegation of “non-allergenic milk.”

One of their main allegations is based on data that BCM-7 alone would be the “villain” in the milk, with which I totally disagree, since milk allergies are a multifactorial health problem.

Your attention would be greatly appreciated.

Jose Luiz M Garcia

Pedro Carrera Bastos’ Response:

Dear Mr. Garcia,

Cow’s milk (CM), as you know, has several proteins, but we can group these proteins into two major ones: whey proteins and caseins. 1 Caseins represent about 80% of the total protein content of CM, as seen in this table. 1

6.12.14-table1Caseins in CM (and also in goat’s milk) are divided into: alphaS1, alphaS2, beta and kappa.2

Following digestive proteolysis of beta-caseins in the human gut (and also after food processing, such as milk fermentation and microbial cheese ripening) there will be a release of bioactive peptides called beta-casomorphins (BCMs). 3 BCMs contain 4-11 amino acids and, more importantly, they are resistant to further proteolysis and express opioid like activity. This means they could potentially bind various opioid receptors in the human nervous system, and also in the gastrointestinal, immune and endocrine systems.3

Beta caseins (as well as the other caseins in CM) are encoded by genes found on bovine chromosome 63 and there are 12 recognized genetic variants of beta-casein: A1, A2, A3, B, C, D, E, F, H1, H2, I and G. A1 and A2 are the most common forms of beta-casein found in dairy cattle in western countries.3

Beta-caseins are proteins with 209 amino acids and the difference between A1 and A2 lies in just one amino acid at position 67: histidine in A1 and proline in A2.3, 4 Apparently, “ancestral cattle” (as well as goats, yak and most sheep) contained the A2 version of beta-casein gene and not the A1 version, which is a single nucleotide polymorphism (SNP) that appeared 5,000 to 10,000 years ago only in Bos taurus, being present today in breeds, such as Holstein, Friesian and Ayrshire.4, 5

The main premise behind the A1/A2 hypothesis is that beta-casein A1, but not A2, will originate the opioid like peptide beta-casomorphin-7 (BCM-7).3, 4 BCM-7 (which contains 7 amino acids) resists further digestion in the human gut, could be absorbed by some individuals, like babies and people with intestinal hyperpermeability, and can influence gut function without being absorbed into the bloodstream.3, 4 The proponents of this hypothesis claim that after being absorbed, BCM-7 could increase low-density lipoprotein oxidation and bind to opioid receptors in the nervous, immune and endocrine systems.3-6

This in vitro and animal data combined with epidemiological studies led to the hypothesis that beta-casein A1 is implicated in Autism and Schizophrenia,3, 4 Type 1 Diabetes,3-5 Cardiovascular Disease,3-6 Sudden Infant Death Syndrome,3 and perhaps even in Metabolic Syndrome (because it could cause insulin resistance).6

In the last years, some important scientific papers have been published criticizing the epidemiological and animal data, and particularly the lack of intervention studies supporting the above causality.5, 7, 8

Having said that, I believe the A1/A2 hypothesis should not be readily dismissed. It deserves to be better studied in animal models and, more importantly, in randomized controlled trials. Nevertheless, when it comes to Type 1 Diabetes (T1D), multiple lines of evidence strongly suggest various CM proteins, and not just beta-casein (which could yield BCM-7), are involved.

Beta-lactoglobulin (BLG)

BLG is a protein found in the whey fraction of CM (but apparently not in the whey of human’s milk) that has structural homology with the human protein glycodelin, which is responsible for the modulation of T-lymphocytes.9 This means that BLG could generate antibodies to glycodelin, and indirectly lead to autoimmunity in genetically susceptible children,9 especially if introduced early in life when there is increased intestinal permeability.9, 10

Bovine serum albumin (BSA)

This is another protein present in the whey fraction of CM. Antibodies against a specific peptide derived from BSA, called ABBOS, have been found repeatedly in the majority of patients with T1D.11-13 This is relevant because there is molecular mimicry between the peptide ABBOS and a beta-cell surface protein p69, one of the autoantigens attacked by T cells in T1D patients.11

Bovine insulin (BI)

CM, human’s milk, and presumably milk from all mammals contains insulin.10 Immunity to BI is common in children who consume cow’s milk or who have been exposed to infant formulas containing cow’s milk.10 Because BI differs from human insulin by only three amino acids, it can generate antibodies against human insulin in genetically susceptible individuals with increased intestinal permeability and other gut dysfunctions10 and/or enteral virus infections in their early years.10, 14

A recent randomized controlled trial (RCT) confirmed the role of BI in T1D.15 In this pilot trial, infants with genetic susceptibility for T1D were assigned to either a “normal” CM based formula, a whey-based hydrolyzed formula, or a whey-based formula “essentially free of bovine insulin” and it was found that the insulin-free formula reduced the cumulative incidence of autoantibodies by age 3 years.15

Interestingly, the RCT gives more support to the role of CM proteins in T1D. In this trial, 230 infants with genetic susceptibility to T1D and at least one family member with T1D received either a casein hydrolysate formula or a conventional, CM-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. The casein hydrolysate formula, as compared with the control, was associated with a decreased risk of positivity for at least one diabetes-associated autoantibody.16

In conclusion, the available evidence cannot firmly confirm or refute a causal role of BCM-7 in T1D. Nevertheless, even if a causal role is confirmed, drinking CM without beta-casein A1 could still represent a risk for people with genetically susceptibility for T1D, since there are various other potential problematic proteins in CM.

Best wishes,

Pedro Bastos, MA, MS, Ph.D. candidate in Medical Sciences at Lund University, Sweden;

Pedro Bastos | About The Paleo Diet TeamPedro Bastos provides consultations, research, and advice to The Paleo Diet community. He is a member of the New York Academy of Sciences, the International Society for the Study of Fatty Acids and Lipids, and the Nutrition Society. Pedro is a certified personal trainer and strength and conditioning instructor, and he holds post-graduate diplomas in exercise and health (from School of Sport Science of Rio Maior, Portugal) and in biochemistry and orthomolecular medicine (from Fernando Pessoa University, Portugal). He received his master’s degree in human nutrition and food quality through Universitat de les Illes Balears (Spain). His research interests are dairy products and human health, nutrition and chronic inflammatory/auto-immune diseases, role of micronutrients in human health, prevention of osteoporosis and sarcopenia, nutrition and liver adenomas, and the role of nutrition in sports injury prevention.


1. Chandan RC. Milk composition, physical and processing characteristics. In Hui YH, Chandan RC, Clark S, et al. Handbook of Food Products Manufacturing – Health, Meat, Milk, Poultry, Seafood, and Vegetables. John Wiley & Sons; 2007: 347-377

2. Park YW, Haenlein GFW. Handbook of milk of non-bovine mammals. Blackwell Publishing; 2006

3. Kamiński S, Cieslińska A, Kostyra E. Polymorphism of bovine beta-casein and its potential effect on human health. J Appl Genet. 2007;48(3):189-98.

4. Woodford K. Devil in the Milk: Illness, health and politics of A1 and A2 milk. Craig Potton Publishing; 2007.

5. Merriman TR. Type 1 diabetes, the A1 milk hypothesis and vitamin D deficiency. Diab Res Clin Pract. 2008:1–8.

6. Lindeberg. Food And Western Disease: Health and Nutrition from an Evolutionary Perspective. Wiley-Blackwell; 2010.

7. Truswell AS. The A2 milk case: a critical review. Eur J Clin Nutr. 2005; 59: 623–631.

8. Clemens RA. Milk A1 and A2 peptides and diabetes. Nestle Nutr Workshop Ser Pediatr Program. 2011;67:187–195.

9. Goldfarb MF. Relation of time of introduction of cow milk protein to an infant and risk of type-1 diabetes mellitus. J Proteome Res. 2008 May;7(5):2165-7

10. Vaarala O. Is it dietary insulin? Ann N Y Acad Sci. 2006 Oct;1079:350-9.

11. Karjalainen J, et al. A bovine albumin peptide as a possible trigger of insulin-dependent diabetes mellitus. N Engl J Med. 1992 Jul 30;327(5):302-7.

12. Pérez-Bravo F, et al. Duration of breast feeding and bovine serum albumin antibody levels in type 1 diabetes: a case-control study. Pediatr Diabetes. 2003 Dec;4(4):157-61.

13. Banwell B, et al. Abnormal T-cell reactivities in childhood inflammatory demyelinating disease and type 1 diabetes. Ann Neurol. 2008 Jan;63(1):98-111.

14. Mäkelä M, et al. Enteral virus infections in early childhood and an enhanced type 1 diabetes-associated antibody response to dietary insulin. J Autoimmun. 2006 Aug;27(1):54-61.

 15. Vaarala O, et al. Removal of Bovine Insulin From Cow’s Milk Formula and Early Initiation of Beta-Cell Autoimmunity in the FINDIA Pilot Study. Arch Pediatr Adolesc Med. 2012 Jul 1;166(7):608-14.

 16. Knip M, et al. Dietary intervention in infancy and later signs of beta-cell autoimmunity. N Engl J Med. 2010 Nov 11;363(20):1900-8.

Kefir Consumption Ill Founded at Best | The Paleo Dit
Hi Dr. Cordain,

Just finished The Paleo Diet for Athletes; I have found it extremely useful so thank you! In the meantime, I noted Chris Kresser has recently been promoting the consumption of Kefir: //chriskresser.com/kefir-the-not-quite-paleo-superfood

If you are able to comment I would be very interested in your views! I entirely understand if you are unable or unwilling to comment. Suspect you probably get a few emails like this!

Keep up the good work!


Dr. Cordain’s Response:

Hi Michael,

Good to hear from you and many thanks for your kind words about The Paleo Diet for Athletes.  I note that Chris Kresser has recently become quite a spokesperson for contemporary Paleo Diets, as he recently appeared on the Dr. Oz TV program, espousing the dietary benefits of both dairy products and legumes in contemporary Paleo diets.  A brief check of Chris’s scientific publication record on PubMed for “Paleo Diets,” or any other topic for that matter, comes up with absolutely zilch — zero ! — nothing !  — no publications whatsoever!  This evidence (or lack thereof) lends little credibility to Chris’s claims as an expert in diet, nutrition or anthropology — much less Paleo Diets.  He has simply never put forth his ideas in peer review, scientific journals.  Nevertheless, the presence of scientific publications or advanced degrees don’t always guarantee expert advice; rather good ideas and rationale thought, supported by solid data frequently do.  Chris’s advice that legumes and dairy are indeed “Paleo” foods that should be regularly consumed in contemporary diets mimicking the nutritional characteristics of our pre-agricultural, hunter gatherer ancestors is ill founded at best.

The Paleolithic period or Old Stone Age is generally defined as the time span in which human ancestors first began to manufacture stone tools (about 2.5 million years ago to 3.2 million years ago) until the beginnings of agriculture in the Middle East about 10,000 years.  During this period all humans and our hominid ancestors lived as hunter gatherers and only consumed wild plant and animal foods available in their environments.

Because it is difficult or impossible to milk wild mammals, humans couldn’t have consumed the milk of another species until they were domesticated, beginning about 10,000 years ago.  Even though 10,000 years ago seems to be incredibly distant from a historical perspective; on an evolutionary time scale it only represents about 330 human generations.1 Hence, dairy products (milk, butter, cheese, yogurt, kefir etc.) are very recent introductions into the human diet and never were components of Paleolithic diets.1 In support of this notion is the very recent evolutionary appearance of genes which allow certain human populations on the planet to digest milk without gastro-intestinal upset.2 In fact, about 65 % of the world’s people are lactose intolerant and cannot drink milk without digestive discomfort.  By fermenting dairy products, it is possible to reduce their lactose content, but not all fermented dairy products (yogurt, kumiss, sour milk etc) are completely lactose free.  So the question comes up, should people consuming contemporary Paleo Diets be regularly consuming a food (kefir or for that matter any dairy product) for which our species has scant evolutionary experience? I have fully addressed this issue in an entire chapter in my most recent book, The Paleo Answer.3

It is not the lactose in milk that is the sole reason to avoid dairy.  Except for calcium, milk and dairy products are relative nutritional lightweights in the 13 nutrients most lacking in the U.S. diet.1, 3 Of seven food groups (seafood, meats, fresh vegetables, fresh fruits, milk, whole grains and nuts), milk ranked 5th for the 13 nutrients most deficient in the U.S. diet.  Seafood, meat, fresh vegetables, fresh fruits and nuts provide humans with all known nutritional requirements4 and represent the major food groups that conditioned the human genome for more than 2.5 million years of evolutionary experience.3 No mammal on earth has a nutritional requirement for the milk of another species, nor do we.

Besides its poor nutritional value and indigestibility for 65% of the world’s people, milk and other dairy products may produce a variety of adverse health effects including: 1) a high insulin response and insulin resistance, 2) an increased risk for cardiovascular disease, 3) an increased risk for acne, 4) an increased risk for many autoimmune diseases including multiple sclerosis, rheumatoid arthritis, Crohn’s disease and ulcerative colitis, 5) an increased risk for food allergies,  6) an increased risk for breast, ovarian, prostate and testicular cancers, 7) an increased risk for senile cataracts 8) dairy products’ high calcium content impairs zinc and iron absorption, and finally 9) increased dairy consumption doesn’t reduce the risk for bone fractures – so why consume them?. The mechanisms underlying these adverse health effects are fully outlined in my chapter on the topic, including more than 100 references to support this information.3

If you think milk is just a healthy white liquid that is “Good for Every Body,” think again! The following non-comprehensive list contains hormones and bioactive substances found in cow’s milk which are either known to, or suspected of causing a number of the deleterious health effects associated with milk and dairy consumption.3

Growth Hormones

  • Insulin, Insulin like growth factor 1 (IGF-1), Insulin like growth factor 2 (IGF-2)
  • Insulin like growth factor binding proteins, 1 to 6 (IGFBP-1, 2, 3, 4, 5, 6),
  • Betacellulin (BTC), Growth hormone (GH), Growth hormone releasing factor (GHRF), Transforming growth factor alpha (TGF α), Transforming growth factor beta 1 (TGF-β1), (TGF-β2), Platelet derived growth factor (PDGF)

Steroid Hormones

  • Estrogens (Estrone, Estradiol-17β, Estriol and Estrone sulfate), Progesterone, 20 alpha-dihydropregnenolone, 5α androstanedione, 5 α pregnanedione, 20α- and 20β-dihydroprogesterone, 5α-pregnan-3β-ol-20-one,  5α-androstene-3β17β-diol, 5α-androstan-3β-ol-17-one, androstenedione, testosterone, and DHEA acyl ester

Bioactive Proteins and Peptides

  • Relaxin, Thyrotropin releasing hormone (TRH), Luteinizing hormone releasing hormone (LHRH), Somatostatin (SIH), Gastrin releasing peptide (GRP), Calcitonin, Adrenocorticotropic hormone (ACTH), Prolactin, Thyroid stimulating hormone (TSH), Lysozyme, Lactoperoxidase, Lactoferrin, Transferrin, Immunoglobulins (IgA, IgM, IgG), Proteose-peptone, Glycomacropeptide, Plasmin, α Casein, β Casein, κ Casein, α Lactoglobulin, β Lactoglobulin, Bovine serum albumen (BSA), Gastric inhibitory polypeptide (GIP), Glucagon-like peptide-1 (GLP-1), Antitrypsin, Plasminogen activator inhibitor-1, α(2) antiplasmin , Butyrophilin, Xanthine oxidase, Mucin-1, Mucin-15, Adipohilin, Fatty acid binding protein, CD36, Periodic acid Schiff 6/7

Bioactive Peptides formed in gut from Milk Proteins

  • Casomorphins, α Lactorphin, β Lactorphin, Lactoferroxins, Casoxins, Casokinins, Casoplatelins, Immunopeptides, Phosphopeptides.


Loren Cordain, Ph.D., Professor Emeritus


1. Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J. Origins and evolution of the western diet: Health implications for the 21st century. Am J Clin Nutr 2005;81:341-54.

2. Cordain, L., Hickey, M. , Kim K. Malaria and rickets represent selective forces for the convergent evolution of adult lactase persistence. In: Biodiversity in Agriculture: Domestication, Evolution and Sustainability, Gepts P, Famula T, Bettinger R et al. (Eds.), Cambridge University Press, Cambridge, UK, 2011, pp 299-308.

3. Cordain L. Just say no to the milk mustache.  In: The Paleo Answer, John Wiley & Sons, New York, NY, 2012, pp. 72-103.

4. Cordain L, The nutritional characteristics of a contemporary diet based upon Paleolithic food groups. J Am Neutraceut Assoc 2002; 5:15-24.

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