www.ThePaleoDiet.com Hello! Welcome to The Paleo Diet Update. For the next several weeks we will be publishing archival issues of The Paleo Diet Update while we work on our new monthly edition of the newsletter. We appreciate your readership, interest, and enthusiasm for The Paleo Diet and hope that you find items of interest from our archival editions of the newsletter. The Paleo Diet, as well as my ongoing research in paleo nutrition, have been featured in several articles and blog posts in recent weeks. A list of the publications - such as the New York Times and the Washington Post - as well as links to the articles are available on my blog. New Products in The Paleo Diet Store I'm pleased to announce that The Dietary Cure for Acne Eating Guide is now available for purchase as a stand-alone product for $29.95. Please visit my web store for more information. In addition, all of the items included in The Complete Acne Elimination Program are now being offered for sale individually. Please visit my web store for more information. The Complete Acne Elimination Program bundles all of these products together, and is a $50 savings compared to buying all of the acne products individually. My DVDs Acne Vulgaris: A Disease of Western Civilization and How to Treat Multiple Sclerosis with Diet are also available for purchase as stand-alone products for $19.95. Please visit my web store for more information. In addition, I'm now selling copies of my previously unpublished papers on Paleo Diet-related topics. The first paper to be offered is Nutritional Differences between Grass and Grain Fed Beef: Health Implication. The paper is available for $19.95. Please visit my web store for more information. Suggested Resources for Buying Paleo-Friendly Food For your information, and to assist you in obtaining Paleo Diet-friendly food, we have provided the following list of suppliers reproduced and updated from The Paleo Diet. The response from the Paleo Diet community to my Paleo Diet Blog continues to be enthusiastic. My team and I will continue to provide useful nutritional information to our readers, as well as an interactive format for readers to view past questions submitted from the Paleo Diet community and the answers provided by our team. We encourage you to check out new articles, browse our Q&A, and submit your own questions or comments. Thank you to our dedicated readers and to the Paleo Diet community for your continued support, and for submitting your questions via email and our blog. We are grateful for the opportunity to expand the community's awareness about the Paleo Diet. Loren Cordain, Ph.D., Professor |
Loren Cordain, Ph.D. |
| In This Issue |
| The Dietary Cure for Acne |
| Relevant Science |
| Questions & Feedback |
To our faithful Paleo Diet Newsletter subscribers, We are proud to announce the publication of the paperback version of The Dietary Cure for Acne. While our readers have known about the relationship between diet and acne for quite some time, this topic has gained more attention recently with the publication of a clinical trial which showed significant results in a group of teenagers following a diet similar to that which we recommend. Though acne affects mainly teenagers, millions of adults worldwide also suffer from this condition. Understanding the impact that diet has on this very visible disease can help us better understand the effect of diet on a wide variety of health conditions. Editors note: This month we asked Dr. Cordain to take a few minutes out of his busy schedule to answer some questions about The Dietary Cure for Acne. Q: Dr. Cordain, for years doctors have told the patients that diet has nothing to do with acne and it appears that some of the science may be proving them wrong. What took so long? Dr. Cordain: Boy, that's a good question. You never know what's responsible for this but what I do know is that the information that the notion that diet didn't cause acne was based on two flawed studies that were published over 30 years ago. The problems with those studies have been pointed out in the scientific literature, but unfortunately, the dermatology community hasn't yet taken it to heart. They haven't changed the dogma in their textbooks. We now have three good epidemiologic studies as well as one dietary intervention that say otherwise, so there is good credible evidence to suggest that diet indeed does underlie acne. Q: You described some anecdotal evidence presented by Dr. Otto Schaefer in the "Dietary Cure for Acne" that first got you interested in this idea. Can you describe that? Dr. Cordain: Sure. Schaefer was a frontier physician who worked with the Inuit or Eskimo people as they made the transition from essentially the Stone Age to the space age. They were living in the far north above the DEW line, or distant early warning line, which was a line of radio stations that was built across Canada in the 1950’s. Schaefer flew in on float planes to these people and he wrote extensively in the scientific literature in the 60’s, 70’s, and early 80’s about what he had witnessed as these people made that transition. He documented that in some of the best journals at the time, and in one of the journals he suggested that acne was absent in these people until they were exposed to the Western diet and the Western way of living. And that actually was the paper I read. It was in a journal called "Nutrition Today", published I believe in 1971 and that really kind of piqued my interest and we pursued it. Q: You just mentioned some of these epidemiological studies that have recently been published, and you actually published one of the first to show a link between diet and acne back in 2002. Can you describe that study and what you guys found?
Q: In the book you talk about the four proximate or immediate causes of acne. Can you go through those? Dr. Cordain: Sure. I think that this has been known for a while. There are a couple of things that happen and I think the first thing that one needs to do is be familiar with the skin pore, also called the pilosebaceous unit. The pilosebaceous unit consists of a canal called the follicle, a hair, and a sebum gland which produces oil. The follicle is lined with skin cells called keratinocytes. The first step in the blockage of the pore is that these keratinocytes become overly adherent to one another and they don't slough off in the normal way. When this process, called desquamation, is impaired, the keratinocytes, or the skin cells lining the pore stay connected and they end up blocking the pore. The second factor that occurs is that the sebum glands produce too much oil within the pore. They produce too much oil because they are stimulated by circulating male hormones, testosterone in the bloodstream; both males and females produce testosterone, and that excessive testosterone then causes too much sebum to be produced.
The final factor is an inflammatory process that causes this whole thing to take off and get worse. Q: The book is called the Dietary Cure for Acne, which implies that diet may actually be causing acne. Is there a scientific evidence to show a connection between diet and these four mechanisms? Dr. Cordain: I think we are just at the beginning stages of understanding how diet causes acne and our research group has proposed that high glycemic foods are one of the major factors underlying the acne. We've also proposed that dairy products underlie acne because even though paradoxically they have a low glycemic index, they spike the insulin levels in a manner similar to high-glycemic foods. So we believe that dairy products and high-glycemic load carbohydrates like refined sugars, refined flours, and processed foods are some of the primary factors involved. Mechanistically, we've speculated on how these may or may not work, but to date there's only been one clinical trial which is Dr. Newman's study from the Royal Melbourne Institute of Technology that was just recently published in two major nutrition journals. And they were able to show that reducing high-glycemic load foods and the glycemic load will actually ameliorate acne symptoms.
Q: So who will this program work for? Dr. Cordain: Well, I think that this will work for most people. We clearly believe that it is genetic susceptibility which predisposes some people to acne. Some people can get by with eating these foods but most can't, given the notion that 90% of all teenagers have acne. So, we believe that the vast majority of people will improve significantly by adopting the diet that we advocate. It is essentially a low-glycemic load diet, high in protein, high in omega-3 fatty acids, and low in lectincontaining foods like wheat. It is also high in animal products which contain zinc, and we know that zinc is a key element in helping to prevent acne. Q: And how quickly might somebody begin to see results?
Q: Are there other health benefits that people might see as a result of eating of this way?
Q: You’ve been offering this book as an ebook for about a year, but even before the Dietary Cure for Acne was written people were sending you some feedback on their results. What have you been hearing from your readers? Dr. Cordain: We regularly hear from people who have had acne for years and tried numerous remedies, who have completely eliminated their acne following this program. You know, this is what we refer to in scientific literature as anecdotal evidence and these are people that adopt this way of eating and they experience improvement and for many people these case histories of individuals that have improvements are very encouraging.
Q: Thank you. Is there else that you would like to add? Dr. Cordain: You know, I just think that this is a disease that many people in the world needlessly suffer from, and it’s a disease that through behavioral modification, i.e., changing parts of their diet, they can experience significant improvements in their symptoms. Many people have reported that they have complete remission of their symptoms when they follow this type of a diet, so they really have nothing to lose but their poor complexions. |
Dr. Cordain: Sure. I would say that ours were the first modern studies that pointed out that there
might be a link between diet and acne, but essentially what we did is we studied two groups of
people that were living in non-Westernized ways. We looked at the Kitavan islanders. This is a
group of people that are horticulturalists and fishermen and their island is off the coast of Papua
New Guinea. At the time we studied them in the early to mid 1990s there were about 3,000 of
them living on the main island. They didn't have electricity and they had no Western goods.
Stefan Lindeberg from the University of Lund in Sweden had studied these people for the last
couple of decades. They went in, looked at them on a cross-sectional basis, and examined them
for acne and found that there wasn't a single case of acne in the entire population including a group
of 300 adolescents. Then we followed that study up with a longitudinal study in which we went
down to Paraguay and we studied the Ache hunter-gatherers. My colleague Kim Hill and his
wife Magdalena Hurtado have been studying this group of non-Westernized people for the last 30
years. We followed around a group of around 50 or 60 Ache over about a two-year period, including
a fairly substantial number of adolescents, and we didn't find a single acne lesion in the entire
group. If we were to look at a group of comparable Western adolescents, we would find that
acne has about a 90% incident rate.
This produces a climate that is ripe for infection of the pore by bacteria that normally live on the outside
of the skin, and that are typically harmless. These are anaerobic bacteria, meaning that they
can function without oxygen. So the oil-filled clogged pore is a nice oxygen-free environment
with a lot of food for the bacteria. They get in there and multiply, causing the painful red, swollen
comedone, what the average person calls a zit.
Mechanistically, we're not able to point out exactly why it is, but we believe that it's because
when insulin levels are elevated, the result is a hormonal cascade that causes this improper desquamation
process. Elevated insulin also promotes elevated male testosterone levels which in
turn increase the sebum production. Furthermore, in the typical Western diet, we tend to have
way too much omega-6 fats and reduced levels of omega-3 which tends to promote the inflammation process.
Dr. Cordain: Well, typically in the inflammatory part of the disease we will actually see results
within days to a week and notice that they're not getting new zits or comedones. To completely
clear their skin, I think it can take anywhere from a month to three months depending upon how
bad they are. Obviously, permanent scarring that has occurred beforehand cannot be cured with
diet, but those who don't have permanent scarring can see significant improvements in their skin
within that window. We believe that that window occurs because of the turnover of keratinocytes.
Keratinocytes are the cells that ultimately plug the pores and they turnover in about a 30-day period.
However, there are comedones that are closed and it takes longer for those to heal up, so that's
why we take it out to a few more months, like a three-month period.
Dr. Cordain: Yes, definitely. Even though it's a diet that can benefit and be therapeutic for acne
patients, this is not a diet per se. This is a lifetime way of eating. This is a diet that will give most
people more energy. They won't have that midmorning letdown. If they have other health complaints,
such as long-term, chronic health problems, high blood pressure, elevated blood cholesterol
levels… it will benefit most of these folks. People that are obese or overweight, they will
tend to normalize their weight. If they have type 2 diabetes, this can improve the insulin metabolism
and may get them completely free and clear of any medication that they may be taking for type 2
diabetes. It also can be beneficial for gout patients, for people with auto-immune disease, and
people with chronic inflammatory disease can benefit from this type of a diet.
For scientists, we need randomized, controlled trials like what we found with the Newman study
to make a strong case for the notion that diet is responsible for acne, and that diet can ameliorate
acne symptoms. We now have three epidemiologic studies and one clinical trial already supporting
the role of diet in acne. We still need to work out all the mechanism, but I think that people
don't necessarily have to wait for all the science to come in. They can go out there right
now, make some changes in their diet and monitor their own symptoms, and hopefully see improvements
immediately. The cost-to-benefit ratio is very minimal.|
Lectins and Autoimmune Disease Rheumatoid Arthritis (RA) is a disease in which the body’s own immune system begins to recognize bone, cartilage, and tissues which serve as a cushion between bones in joints as foreign bodies and will begin to systematically destroy or degrade these tissues. This leads to extreme pain, inflammation, stiffness, and eventual immobility of certain joints. Though the cause of RA is still largely unknown, it has long been known that RA symptoms are highly correlated with inflammation of gut. In this review of RA published in 2000, Dr. Cordain offered some interesting theories of how specific dietary elements may be contributing to both an inflamed gut and RA symptoms. Gut inflammation is known to increase intestinal permeability, so that the gut becomes less capable of limiting the substances that cross the gut barrier and into the blood stream. Interestingly, 67% of all RA sufferers also suffer from gut inflammation. In this article Dr. Cordain suggested that specific substances known as dietary lectins may be involved in both the inflammation of the gut and in facilitating the movement of bacteria from the gut into the blood stream. Specific dietary lectins, found in wheat, grains, and legumes, have been shown in animal models to damage intestinal cell walls, leading to an inflamed state. This inflammatory state allows passage of bacteria and other foreign proteins into the blood stream that simply should not be allowed there. Additionally, dietary lectins have been shown to facilitate the preferential growth of specific gut bacteria often associated with RA symptoms. These bacteria share a sequence of proteins very similar to many of our own body’s protein sequences. Immune cells ‘read’ the protein sequences on the bacteria and may begin to associate similar self-proteins with these foreign substances, thus attacking both the bacteria and our own tissues. Lectins themselves have been shown to be capable of crossing a damaged gut membrane and entering into the bloodstream in tact. It is not known whether dietary lectins bind to synovial tissues in joints. However, in animal models when lectins were injected directly into joints the result was a massive immune response followed by the destruction of joint tissue. If lectins are indeed binding to synovial tissues, this coupled movement of gut bacteria into the blood and lectins' own ability to cause an immune response may be large factors influencing RA symptoms. Knowing as we do that inflammatory guts and RA are strongly correlated and that dietary lectins are potential causers of inflamed guts it is to our benefit to examine further the connection between the two events and the dietary mechanisms through which these events may be triggered.
Cordain L, Toohey L, Smith MJ, Hickey MS. Modulation of immune function by dietary
lectins in rheumatoid arthritis. Brit J Nutr 2000, 83:207-217. Lectin-based Food Poisoning In The Dietary Cure for Acne Dr. Cordain discusses how lectins can inhibit the activity of certain zinc dependent enzymes necessary for the proper breakdown and ‘sloughing off’ of skin cells; a process known as exocytosis. Now research done by the Medical College of Georgia has shown that specific lectins are toxic to certain intestinal cells and can even cause cell death. Similar to the acne story, the lectins present on damaged intestinal cells were shown to prevent the normal process of exocytosis of certain mucus cells needed to keep intestinal cells healthy. Gastro-intestinal (GI) epithelial cells are constantly exposed to mechanical damage within our stomach and intestines. Fortunately, they have a rapid repair mechanism which typically seals the damaged cell with mucus within seconds to prevent any unwanted food-stuffs from entering our blood stream. However, lectins may be delaying or completely inhibiting this repair process. This is theorized to be the cause some of the GI discomfort experienced with ingestion of beans, or wheat germ agglutinin in those with celiac disease. Scientists at the Medical College of Georgia introduced a variety of lectins to cultured rat’s gastrointestinal (GI) epithelial cells to examine lectins' potential for binding these cells. Wheat Germ Agglutinin was found to bind most readily. Next scientists created ruptures in the GI epithelial cells using both a laser and a syringe needle to mimic the natural process of cell damage seen during digestion of solid foods. Once damaged, scientists determined the ability of the cells to repair themselves by observing the influx of a dye present in the solution that will not pass through an intact epithelial cell. The GI epithelial cells coated with Wheat Germ Agglutin were incapable of healing and dye leaked through the damage site without restraint. You can imagine if this were an actual stomach cell within the body being incapable of repairing itself and the subsequent ‘leaking’ of stomach and intestinal contents directly into the bloodstream. Scientists went on to investigate lectins’ potential for inhibiting the secretion of mucus necessary for GI epithelial cell repair. A culture of mucus secreting GI tract and colon cells were bathed in Wheat Germ Agglutinin and then damaged. Dramatic decreases in mucus secretion (mucus necessary for healing) were observed in concurrence with abnormally large amounts of cellular death in the area surrounding the damage site. The scientists then concluded that lectins are potent inhibitors of mucus secretion in GI epithelial cells and are toxic and even deadly to damaged GI epithelial cells with the likely mechanism being an interruption in exocytosis of mucus from mucus secreting GI and colon cells.
Miyake K, Tanaka T, McNeil PL. Lectin-based food poisoning: a new mechanism of protein
toxicity. PLoS ONE. 2007 Aug 1;2(1):e687. Diet and Acne A recently performed dietary intervention published in the Journal of American Academy of Dermatology has examined whether one of two particular diets prescribed to participants was to be more effective than another at decreasing the severity of acne symptoms in the participants. The intervention recruited 43 male subjects between the ages 15 and 25, all with mild to moderate acne symptoms. Subjects were assigned randomly to either a high Glycemic-load (HGL) diet or a low Glycemic-load (LGL) diet. Details of subjects' height, weight, body fat percentage, body mass index, and, most importantly, their visible acne lesion count, were collected at 0, 4, 8, and 12-weeks on their prescribed diet. Also investigated were the accompanying changes, if any, observed in subjects’ fasting levels of insulin, blood glucose, and other markers correlated with acne severity. Subjects within the LGL experimental group were educated about the Glycemic index and on how to replace high Glycemic-index foods with foods containing higher protein content and with lower Glycemic-indices (meats, whole grains, and fruits). The control HGL group was not educated about the Glycemic index and was instructed to include carbohydrates regularly as a part of their diet. Compliance was strictly monitored using several control mechanisms. After twelve weeks the results of the intervention were apparent to investigators. The LGL dieters experienced a significantly greater reduction in acne lesion count than did the HGL diet counterparts. In addition, LGL dieters improved their weight, body fat percentages, and waist circumferences significantly. Also of interest were the changes observed in the LGL dieters’ insulin sensitivity levels and how it directly correlated with their decreased acne lesion counts, indicating a relationship between insulin sensitivity and acne severity.
Smith, R.N., Mann, N.J., Braue, A., Makelainen, H., Varigos, G.A., The effect of a high-protein,
low Glycemic-load diet versus a conventional, high Glycemic-load diet on biochemical parameters
associated with acne vulgaris: A randomized, investigator-masked, controlled
trial. Journal of American Academy of Dermatology 2007; 57:247- 256. |
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Dr. Cordain, In Wikipedia (http://en.wikipedia.org/wiki/Paleolithic_diet), there is an article on the Paleo diet. In the "criticism section" for the diet is the following: "Ignorance of real Paleolithic diets: Archeological evidence and the study of modern-day huntergather societies has shown that many preagricultural peoples exploited wild grains, legumes, and tubers. Often, they undergo complex processing to make them edible (i.e. bush bread). These are the same foods which are vilified in the "Paleolithic" diet. Ray Mears, Gordon C. Hillman (20 Sep 2007). Wild Food. Hodder & Stoughton, 320. ISBN 0340827904." Are you aware of any peer-reviewed evidence at all that may support this claim (even if you believe it does not prove what is claimed)?
Thanks, Hi David, In 2000 we published a paper in the American Journal of Clinical Nutrition (Plant to animal subsistence ratios and macronutrient energy estimations in world wide hunter-gatherer diets) in which we showed that wild tubers would indeed have been a common component in historically studied hunter-gatherer diets, comprising 23.6% of all the plant food consumed by the average hunter-gatherer. Our point was that high glycemic load tubers (such as potatoes, which were developed from intensive agricultural inbreeding of wild types) would not have been part of pre-agricultural diets. Most tubers and many underground plant structures (corms, roots, etc) are inedible unless cooked. Cooking serves to breakdown the cell walls and make the starch available for absorption and it also inactivates potentially toxic compounds. Hence, until hominins could regularly control fire (~300,000 years ago), most roots were inedible. Historical and ethnographic studies of hunter gatherers indicate that cereal grains were rarely consumed. However, there are some notable exceptions: Holocene hunter gatherers living in marginal areas such as desert ate grains seasonally such as the Great Basin Indians in the U.S. and Australian Aborigines. More importantly, for most of humanity’s existence on the planet, up until the very end of the Paleolithic period grains were never consumed. Grains are virtually indigestible unless the cell walls are broken via (grinding or milling) and the starch is gelatinized by cooking. Hence the appearance of stone grinding tools (mortar and pestle, saddle stones etc) heralds the widespread use of grains in hunter-gatherer societies. The first documented record of stone grinding tools appearing in the fossil record occurs 22,500 – 23,500 years ago in the near East (Piperno DR et al. Processing of wild cereal grains in the Upper Paleolithic revealed by starch grain analysis. Nature 2004;430:670-73), and the first hunter gatherer society known to have made wide scale use of grains were the Natufians who lived in the Levant ~13,000 years ago. Hence, cereal grains have little or no evolutionary precedent in hominin diet. 
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