Tag Archives: depression

Oyters on Grill |The Paleo Diet

Zinc! It’s the essential mineral that’s praised by many advocates involved in the Paleo community. Most people generally recognize zinc for its reputation as a potent cold and flu virus prevention solution, but its numerous benefits also extend beyond its role as an immunity-boosting mineral.

Ensuring adequate zinc intake in one’s diet is absolutely necessary for achieving long term health goals while following an ancestral eating plan. Zinc is essential for maintaining numerous physiological functions within the human body including tissue and epithelial integrity, immune system regulation, cellular growth, gut health, and inflammation suppression. The current USA government’s recommended daily allowance (RDA) for zinc averages in at approximately 10 mg. The USA RDA for zinc might be adequate for maintaining proper zinc levels for most healthy human beings that do not suffer from a zinc deficiency, but higher short-term dosages are likely needed to correct a deficiency. Physical indications of zinc deficiency include but are not limited to frequent viral infections, white spots or streaks on the fingernails, poor physical growth in childhood, hair loss, impaired vision, diarrhea, acne, dandruff, chronic dry skin, and impaired mental functioning (i.e. depression, anxiety, brain fog). It’s worth noting that all of the listed conditions can also result from the manifestation of other nutrient and mineral imbalances, and ensuring a highly varied nutrient rich ancestral diet that is rich in omega-3’s is crucial to preventing and resolving any of the aforementioned health issues.

Zinc in excess can be equally problematic as zinc deficiency. The daily upper limit threshold for zinc in healthy individuals is about 40 mg for adults over 19 and 25mg for those under 19. Excessive zinc consumption is characterized by severe headaches, nausea, vomiting, and decreased appetite. Over the long term, excessive zinc intake in the absence of copper will result in the gradual depletion of copper from the human body. For this reason it is recommended that those looking to supplement zinc in their diets should avoid zinc dietary supplements and instead opt for “au-naturel” food-based sources of zinc that are inherently proportionately balanced with copper.

Those looking to ensure optimum zinc intake in their diet must decide whether to source their zinc from animal sources or plant sources. Below are two tables demonstrating a handful of the highest ranking sources of zinc from both plants and animals. The zinc content of each source is listed in mg. Note that many of the listed zinc-rich plant foods do not adhere to the Paleo lifestyle.

Zinc Sources Table | The Paleo Diet

When examining the table above, it becomes obvious that ratio of zinc in animal-based foods is significantly higher than the ratio of zinc found in plant-based foods. Additionally, all of the animal-based sources of zinc naturally have appropriate zinc to copper ratios, so you don’t have to worry about creating a mineral imbalance while consuming these foods.

Now you might be wondering if it is still worth considering plant-based sources of zinc in your diet. From the tables above, it is immediately apparent that one would have to consume much higher quantities of zinc-containing plant foods to achieve the same proportion of zinc found in the animal foods listed above. Besides pumpkin seeds and sunflower seeds, all of the other listed plant-based zinc sources are off limits for Paleo followers. Additionally, it is worth mentioning that many of the zinc-rich plant foods such as legumes, seeds, nuts, and grains contain phytates (i.e. phytic acid). Phytates have been demonstrated to bind to zinc and other important dietary minerals such as iron and manganese. The bonding of phytates with zinc and other minerals upon digestion drastically reduces your body’s ability to absorb these key minerals, thus making you more prone to mineral deficiencies. Animal foods do not inhibit the absorption of zinc or other minerals and instead aid in absorption during digestion.

Oysters rank supreme amongst all other zinc containing food sources available for human consumption, and thus are ideal for treating individuals with zinc deficiency, and for those simply looking to incorporate zinc-rich food sources into their diets.

Oysters have long been revered for their rich taste and nutritional qualities across all parts of the globe. Preference for oyster consumption has shown up in historical documentation dating back to the ancient Greeks and Chinese. In fact, in Europe up until the 18th century oysters were considered a “luxury” food only reserved for the highest classes. Within the colonies of North America, oyster consumption was never restricted to the rich and thus most colonists and Native Americans consumed oysters regularly. The 19th century in The United States was marked by the widespread establishment of “oyster bars” that originated on the eastern seaboard and quickly became popular throughout the west. By 1881 there were nearly 379 oyster bars in Philadelphia alone! Zinc deficiency was likely not a major problem for oyster-loving 19th century Americans.

Nowadays oysters are becoming an increasingly obsolete food source. Oysters can be difficult to source fresh, especially if you are like myself and live thousands of miles inland from the nearest ocean. The best economical solution for inlanders is to purchase canned oysters from your local grocery store. A large majority of the oysters on store shelves are canned in cottonseed oil, which you will definitely want to avoid if you are sticking to a Paleo eating plan. Fortunately, Crown Prince offers a line of smoked oysters that are canned in extra-virgin olive oil. I have seen these oysters available in Sprouts, Whole Foods, and Trader Joe’s for about $2 – $3 per can. If you are not quite adjusted to the “delicious” taste of oysters yet, try topping them with a few drops of Paleo-friendly hot sauce.


1. Berger, Abi. “What does zinc do?.” BMJ 325.7372 (2002): 1062.
2. Hambidge, M. (2000). Human zinc deficiency. The Journal of nutrition,130(5), 1344S-1349S.
3. Lönnerdal, B. O. (2000). Dietary factors influencing zinc absorption. The Journal of nutrition, 130(5), 1378S-1383S.
4. Ma, J., & Betts, N. M. (2000). Zinc and copper intakes and their major food sources for older adults in the 1994–96 continuing survey of food intakes by individuals (CSFII). The Journal of nutrition, 130(11), 2838-2843.
5. Office of Dietary Supplements – Zinc. (n.d.). Retrieved December 28, 2015, from https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/

Refined Carbohydrates May Increase Your Risk of Depression | The Paleo Diet

At the core of healthy living and Paleo lies the movement against refined carbohydrates. In addition to the risk of excess weight gain, many already know that it leads to further known health complications such as poor cardiovascular health, and diabetes. Adherence to the right nutrition is associated with not only promoting good physical well-being, but mental health as well.

A recent study conducted at Columbia University was published in the American Journal of Clinical Nutrition showed consuming a diet full of refined carbohydrates such as white bread and pasta increases an individual’s risk of depression.1 On the flip side, their findings suggested a diet rich in roughage (high-fiber plants) and vegetables decreases the risk of depression.2


Poor nutrition has long been identified as a key cause of depression. Previous longitudinal studies have shown an association between sweetened beverages, refined foods, and pastries, and an increased risk of depression.3

Depression is a mental health condition that negatively impacts all areas of a person’s life.4 The medical diagnosis suggests an individual is in a depressed mood or has lost interest or pleasure in almost every form of daily activity for at least two weeks.5 With an estimated 350 million people globally suffering from depression, this landmark study deserves exposure and can play a chief role in both preventing and treating the condition.

So, what exactly is the connection between nutrition and depression? Well, eating refined carbohydrates causes a huge spike in blood sugar. High blood sugar induces a hormonal response resulting in the release of insulin.6 Consequently, blood sugar levels decrease to a point where a counter regulatory response occurs.6 The spikes and crashes are commonly associated with the varying mood changes of depression. Spikes often parallel increased hunger, irritability and anxiety whereas crashes oscillate with extreme tiredness or fatigue, and depression can occur.6

Just think about the times you may have “mistakenly” eaten one too many servings of a very sweet dessert, experienced a sugar high and then fallen victim to the dreaded crash.


This particular study used a large cohort (group) of 70,000 postmenopausal women who took part in the National Institutes of Health’s Women’s Health Initiative Observational Study between 1994 and 1998. The main variables observed were the dietary glycemic index, glycemic load, types of carbohydrates consumed, and depression.7

Previous studies have shown a positive correlation between how refined a carbohydrate is and the glycemic index (GI). The more refined it is, the higher the glycemic index on the scale. A standard GI scale starts at 0 and ends at 100, and helps with measuring postprandial blood sugar levels, which are blood sugar levels after eating. White bread and white rice, along with sweetened beverages were high on the GI scale.

Researchers found the higher the GI scores, the greater the risk of developing new-onset depression in post-menopausal women. Given the link between higher consumption of dietary fiber, whole grains, vegetables and non-juice fruits, the school of thought suggests the process of refining strips the food of a key nutrient: fiber. The benefits of fiber in the body, including decreasing blood cholesterol and type 2 diabetes are well documented.8 Studies have long associated increased dietary fiber with a decreased risk of colon cancer as well.8


Adhering to a nutritional regime like the Paleo diet, which is rich in fiber and vegetables, can play a role in treatments and preventive measures for depression. Notwithstanding, the study does have limitations and begs the question as to whether the link between nutrition and depression bears a cause-effect relationship.9 Is depression the root cause of an individual making poor food choices, for example? Nevertheless, the study shows great potential and reminds us the tremendous impact our nutrition choices can have on our health and well-being.



[1] Gangwisch J, Hale L, Garcia L, Malaspina D, Opler M, Payne M, et al. High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative. American Journal of Clinical Nutrition. 2015 Aug 5.

[2] Physicians Committee For Responsible Medicine. How Fiber Helps Protect Against Cancer. [Online].; 2015 [cited 2015 Aug 21. Available from: //www.pcrm.org/health/cancer-resources/diet-cancer/nutrition/how-fiber-helps-protect-against-cancer.

[3] Sathyanarayana Rao T, Asha M, Ramesh B, Jagannatha Rao K. Understanding nutrition, depression and mental illnesses. Indian J Psychiatry. 2008 Apr-Jun; 50(2): p. 77-82.

[4] World Health Organization. Depression. [Online].; 2012 [cited 2015 Aug 21. Available from: //www.who.int/mediacentre/factsheets/fs369/en/.

[5] MedlinePlus. Depression. [Online].; 2014 [cited 2015 Aug 21. Available from: https://www.nlm.nih.gov/medlineplus/ency/article/003213.htm.

[6] Sathyanarayana Rao T, Asha M, Ramesh B, Jagannatha Rao K. Understanding nutrition, depression and mental illnesses. Indian J Psychiatry. 2008 Apr-Jun; 50(2): p. 77-82.

[7] Gangwisch J, Hale L, Garcia L, Malaspina D, Opler M, Payne M, et al. High glycemic index diet as a risk factor for depression: analyses from the Women’s Health Initiative. American Journal of Clinical Nutrition. 2015 Aug 5.

[8] Physicians Committee For Responsible Medicine. How Fiber Helps Protect Against Cancer. [Online].; 2015 [cited 2015 Aug 21. Available from: //www.pcrm.org/health/cancer-resources/diet-cancer/nutrition/how-fiber-helps-protect-against-cancer.

[9] US Department of Health & Human Services. Could Too Many Refined Carbs Make You Depressed? [Online].; 2015 [cited 2015 Aug 21. Available from: //healthfinder.gov/News/Article/702150/could-too-many-refined-carbs-make-you-depressed.

Can Paleo Improve Low Mood & Depression? | The Paleo Diet

Low mood and depression are increasingly prevalent symptoms of 21st century living. While the current statistics from the Center for Disease Control show one in ten people suffer from depression, in clinical practice we see much higher rates of people struggling with unreported low mood or depressive symptoms.

The World Health Organization has estimated that by the year 2050, one-third of the global population will suffer from either anxiety or depression. What is going on? Why are we more prone to depression today than in generations past?

As with any complex condition, there are many factors at play that conspire to create an environment where low mood and depression can thrive. Let’s look at how a Paleo diet can lay the framework for better mental health by addressing influential systems of the body.


Today, 75% of the North American population are classified as overweight or obese and the annual consumption of processed and simple sugars tops a whopping 160 pounds of sugar per person. This leads to worsening blood sugar control and insulin dysfunction. Research from Scandinavia has uncovered a clear association between elevated HbA1c (a three-month average of blood sugars) and insulin levels with increased risk of depression. A recent study found that young men with insulin resistance were three times more likely to suffer from severe depression.1

Another study in Diabetes Care of over 4,000 people showed depressive symptoms were associated with higher fasting and 30-minute insulin levels.2 The authors specifically noted that antidepressant medications did not alter this association because the medications target neurotransmitters (e.g. serotonin, dopamine) and do not address blood sugar and insulin dysfunction.

Adopting a Paleo diet can dramatically improve blood sugars and insulin levels, an important first step for reducing risk factors for low mood and depression.


Inflammation is another potential root cause of low mood. Low-grade systemic inflammation leads to the over-production of pro-inflammatory cytokines that are associated with depression.3 The prestigious New England Journal of Medicine recently published a review of the growing connection between chronic inflammation and the development of today’s most common chronic diseases, including depression.4 The current medical literature tells us that if you are overweight or obese, you likely have low-grade systemic inflammation.5

A Paleo diet’s high nutrient density provides a robust intake of antioxidants that help to cool inflammation and reduce the damaging effects of reactive oxygen species (ROS) produced during the inflammatory response. A Paleo diet is also a rich source of anti-inflammatory omega-3 fats that support positive mood. Studies show low levels of omega-3 fats are associated with a chronic stress state and increased risk of depression.6


The microflora of the gut plays a key role in your health and is in constant communication with the brain. Key neurotransmitters targeted by medications for improving symptoms of depression – serotonin and dopamine – are actually concentrated in the gut. The research shows that if you are overweight, you will likely have poor zonulin function, a key molecule that regulates gut permeability.7  Poor zonulin function leads to symptoms of a leaky gut, which exacerbates inflammatory levels and can contribute to the cytokine storm that leads to low mood and depression.

You don’t need to be overweight to suffer from leaky gut. The research is clear that chronic or excessive use of NSAIDs – non-steroidal anti-inflammatory drugs – like ibuprofen and naproxen are also a direct cause of leaky gut, which will worsen inflammation.8,9  A Paleo approach to eating supports the growth of good gut bacteria and, therefore, superior intestinal health.


Movement is a critical component of mental health and overall wellbeing. Busy workdays make it difficult for people to find time to exercise, however this is a critical component of any mental health plan. A recent meta-analysis of 92 studies on more than 4,310 people showed that light to moderate exercise significantly reduced the incidence of depression.10 Try adding 15-20 minute walks at lunch or the end of your day to increase your activity level.

Strength training can also play a key role in mental health. Basic movements like squatting, lunging, bending, pushing, and pulling are deeply engrained in our DNA and exert tremendous positive benefit on multiple systems of the body: improving blood sugars and insulin, reducing inflammation, boosting testosterone (low levels have been associated with depression), and supporting healthy gut flora. If you’re not active, start slowly with 10-20 minutes of strength training 2-3 times weekly and focus on bodyweight type movements.

There is no “magic bullet” to fix depression. It’s a complex multi-factorial condition that is impacted by numerous systems of the body. By addressing blood sugar imbalances, weight gain, inflammation and dysbiosis, a Paleo diet can provide the body with the building blocks it needs to support positive mood.

If you suffer from depression, talk to your doctor about how you can incorporate a Paleo diet and exercise, along with treatment into your action plan.



1. Timonen. M et al. Insulin resistance and depressive symptoms in young adult males: Findings from Finnish military conscripts. Psychosom Med 69(8):723-28.

2. Pyykkonen AJ et al. Depressive symptoms, antidepressant medication use, and insulin resistance: the PPP-Botnia Study. Diabetes Care. 2011 Dec;34(12):2545-7.

3. Felger J, Lotrich FE. Inflammatory cytokines in depression: neurobiological mechanisms and therapeutic implications. Neuroscience. 2013 Aug 29;246:199-229.

4. Emerging Risk Factors Collaboration. Diabetes mellitus, fasting glucose, and risk of cause-specific death. New England Journal Medicine, Mar 2011;364;9:328-341.

5. G. S. Hotamisligil, N. S. Shargill, and B. M. Spiegelman, “Adipose expression of tumor necrosis factor-α: direct role in obesity-linked insulin resistance,” Science, vol. 259, no. 5091, pp. 87–91, 1993.

6. Larrieu T, et al. Nutritional omega-3 modulates neuronal morphology in the prefrontal cortex along with depression-related behaviour through corticosterone secretion. Transl Psychiatry. 2014 Sep 9;4:e437.

7. Moreno-Navarrete JM et al. Circulating zonulin, a marker of intestinal permeability, is increased in association with obesity-associated insulin resistance.. PLos One 2012;7(5):e37160.

8. VanWijck K et al. Aggravation of exercise-induced intestinal injury by Ibroprofen in athletes. Med Sci Sports Exerc. 2012 Dec;44(12):2257-62.

9. Matsui H et al. The pathophysiology of non-steroidal anti-inflammatory drug (NSAID)-induced mucosal injuries in stomach and small intestine. J Clin Biochem Nutr. 2011 Mar;48(2):107-11.

10. Rebar A, et al. A Meta-Meta-Analysis of the effect of physical activity on depression and anxiety in non-clinical adult populations. Health Psychol Rev. 2015 Mar 5:1-78.

Preventing Vitamin B12 Deficiency with the Paleo Diet |The Paleo Diet

We require vitamin B12 for proper red blood cell formation, various neurological functions, DNA synthesis, and much more. Vitamin B12 deficiency is a serious issue, especially for the elderly, partly because we produce lower levels of stomach acid when we age. In food, vitamin B12 is bound to protein and requires the activity of hydrochloric acid and gastric protease to liberate the B12, thereby enabling absorption.1

The Food and Nutrition Board at the Institute of Medicine (IOM) recommends 2.4 mcg of B12 daily for adults and children 14 years or older. According to the National Health and Nutrition Examination Survey (NHANES), mean daily B12 intake for the US population is 3.4 mcg.2 Although most people are above the recommended intake level, a significant segment of the population may be B12 deficient.

The Framington Offspring Study, for example, found B12 deficiency rates to be similar among adults in three different age groups (26–49 years, 50–64 years, and 65 years and older).3 According to the study, nearly two fifths of the population (39%) has plasma B12 levels in the “low normal” range or lower.

A primary consequence of insufficient B12 is vitamin deficiency anemia, also known as megaloblastic anemia or pernicious anemia.4 Vitamin deficiency anemia is different from the anemia caused by insufficient iron, but is no less serious. Vitamin deficiency anemia is characterized by immature or incompletely developed red blood cells, which crowd out healthy red blood cells.

Red blood cells transport oxygen throughout the body and without sufficient supplies, various tissues and organs are underserved. Symptoms of vitamin deficiency anemia include fatigue, muscle weakness, loss of appetite, diarrhea, and numbness or tingling of the hands and feet.

Vitamin B12 deficiency is also suspected to promote various neurological disorders, including depression and dementia.5 Researchers have observed associations between low B12 and depression, both among severely depressed patients and the general population, but haven’t identified a causal mechanism.6 If there is one, however, it probably involves homocysteine.

Homocysteine is a metabolite of the amino acid methionine. Influenced by dietary and genetic factors, homocysteine is normally present in the blood. At elevated levels, however, it’s a risk factor for scores of diseases and conditions, including cardiovascular disease, stroke, osteoporosis, infertility, depression, and dementia. Increased homocysteine is a functional marker of B12 (as well as folate) deficiency.7 According to a 2005 study published in the Journal of Psychopharmacology, “There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression.”8

Preventing Vitamin B12 Deficiency with the Paleo Diet

So how can the Paleo Diet help us maintain increased B12 levels? First, the Paleo Diet includes many B12-rich foods. Eating clams and/or liver once per week, for example, is an excellent strategy for consuming sufficient quantities of B12. The chart to the left shows the B12 levels for common Paleo foods. Second, it’s one thing to consume enough B12, but another thing to absorb it.

The Paleo Diet improves gut health by eliminating foods that irritate the gut (grains, sugar, dairy, vegetable oils, alcohol, caffeine), while embracing foods that heal the gut (fermented vegetables, bone broth, fermentable fibers, and healthy fats). Because the Paleo Diet promotes a healthy gut while featuring many vitamin B12-rich foods, Paleo Diet adherents are likely to maintain healthy B12 levels.

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] Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press, 1998.

[2] Ervin, RB, et al. (March 2004). Dietary intake of selected vitamins for the United States population: 1999-2000. Advance Data from Vital and Health Statistics, 339. National Center for Health Statistics. Retrieved from //www.cdc.gov/nchs/data/ad/ad339.pdf

[3] Tucker, KL, et al. (February 2000). Plasma vitamin B12 concentrations relate to intake source in the Framingham Offspring Study. American Journal of Clinical Nutrition, 71(2). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/10648266?dopt=Abstract

[4] Mayo Clinic Staff. Diseases and Conditions: Vitamin deficiency anemia. Retrieved from //www.mayoclinic.org/diseases-conditions/vitamin-deficiency-anemia/basics/causes/con-20019550

[5] Bottiglier, T. (December 1996). Folate, vitamin B12, and neuropsychiatric disorders. Nutrition Reviews, 54(12). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/9155210

[6] Coppen, A, et al. (January 2005). Treatment of depression: time to consider folic acid and vitamin B12. Journal of Psychopharmacology, 19(1). Retrieved from //www.ncbi.nlm.nih.gov/pubmed/15671130

[7] Ibid, Coppen.

[8] Ibid, Coppen.

Depression and Anxiety | The Paleo Diet

Dr. Cordain,

I’m 36 years old, and 5 ft 8.5 in tall. I started the Paleo Diet about four months ago. Since then I’ve lost almost 25 pounds, bringing me down to my ideal weight of 150. My blood pressure went from 115/70 to 92/56. I decided to try the Paleo Diet because I read (on About.com) that it may help alleviate depression and anxiety. To my delight, it worked – my depression and anxiety have disappeared. My energy levels are much higher than before. I’m no longer tired throughout the day. My mind is clearer – I can focus much more easily, and my short-term memory has improved greatly. My skin is much smoother and less dry. Another improvement that I’ve found, which is kind of strange to me because I never expected it, is that my shinbones are no longer really sensitive. It used to be that if I barely bumped my shinbones against something, the pain was quite bad. Now they’re hardly sensitive at all.


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