A short history of the human food supply

The real goal of nutrition is the management of cellular inflammation. Increased cellular inflammation makes us fat, sick, and dumb (how about overweight, ill, and less intelligent). Strictly speaking, diets are defined by their macronutrient balance. This is because that balance determines the resulting hormonal responses. This doesn’t mean you can ignore the impact of various food ingredients on the generation of cellular inflammation.

This is why I categorize food ingredients into three major classes depending on when they were introduced into the human diet. The more ancient the food ingredients, the less damaging inflammatory impact they will have on turning genes off and on (i.e. gene expression). This is because the greater the period of time our genes have co-evolved with a given food ingredient, the more our body knows how to handle them. Unfortunately, human genes change slowly, but changes in our food supply can happen very rapidly.

With that as a background, let me describe the three major categories of food ingredients, especially in terms of their introduction to the human diet.

Paleolithic Ingredients

This category includes food ingredients that were available more than 10,000 years ago. Our best evidence is that humans first appeared as a new species in Southern Africa about 200,000 years ago (1). For the next 190,000 years, food ingredients of the human diet consisted of animal protein (grass-fed only), fish, animal and fish fats, fruits, vegetables, and nuts. I call these Paleolithic ingredients. This means for the first 95 percent of our existence as a species, these were the only food ingredients that genes were exposed to. As a result of 190,000 years of co-existence with our genes, these food ingredients have the least inflammatory potential on our genes.

Our best estimate of the macronutrient composition of the typical Paleolithic diet some 10-15,000 years ago was 25-28 percent protein, 40 percent carbohydrate, 32-35 percent fat with a very high intake of EPA and DHA (about 6 grams per day) and a 1:1 ratio of omega-6 to omega-3 fats (2). This is basically the composition of the anti inflammatory diet (3-5). If you use only Paleolithic ingredients, then you are almost forced to follow an anti inflammatory diet. The food ingredients are more restrictive, but the increased anti-inflammatory benefits are well worth it.

Mediterranean Ingredients

The second group of food ingredients represents those food choices that were available 2,000 years ago. We started playing Russian roulette with our genes 10,000 years ago as we started to introduce a wide variety of new food ingredients into the human diet. First and foremost was the introduction of grains, but not all at the same time. Wheat and barley were introduced about 10,000 years ago with rice and corn coming about 3,000 years later. Relative latecomers to the grain game were rye (about 5,000 years ago) and oats (about 3,000 years ago).

At almost the same time came the first real use of biotechnology. This was the discovery that if you fermented grains, you could produce alcohol. Alcohol is definitely not a food ingredient that our genes were prepared for (and frankly our genes still aren’t). I think it only took mankind about 10 years to learn how to produce alcohol, which probably makes the first appearance of beer occurring some 9,990 years ago. Wine was a relatively late arrival appearing about 4,000 years ago. With the domestication of animals (some 8,000 years ago) came the production of milk and dairy products. About 5,000 years ago, legumes (beans) were also introduced. Legumes tend to be rich in many anti-nutrients (such as lectins) that must be inactivated by fermentation or boiling. Needless to say, these anti-nutrients are not the best food ingredients to be exposed to.

I call this second group of food ingredients Mediterranean ingredients since they are the hallmark of what is commonly referred to as a “Mediterranean diet” (even though the diets as determined by macronutrient balance in different parts of the Mediterranean region are dramatically different). Those cultures in the Mediterranean region have had the time to genetically adapt to many of these new ingredients since all of these ingredients existed about 2,000 years ago.

Unfortunately, many others on the planet aren’t quite as fortunate. That’s why we have lactose intolerance, alcohol-related pathologies, celiac disease, and many adverse reactions to legumes that have not been properly detoxified. As a result these Mediterranean ingredients would have greater potential to induce increased levels of cellular inflammation than Paleolithic ingredients. However, at least they were better than the most recent group, which I term as, the “Do-You-Feel-Genetically-Lucky” group.

Do-You-Feel-Genetically-Lucky Ingredients

Unfortunately, these are the food ingredients that are currently playing havoc with our genes, especially our inflammatory genes. You eat these ingredients only at your own genetic risk. The first of these was refined sugar. Although first made 1,400 years ago, it didn’t experience a widespread introduction until about 300 years ago. With the advent of the Industrial Revolution came the production of refined grains. Products made from refined grains had a much longer shelf life, were easier to eat (especially important if you had poor teeth), and could be mass-produced (like breakfast cereals).

However, in my opinion the most dangerous food ingredient introduced in the past 200,000 years has been the widespread introduction of refined vegetable oils rich in omega-6 fatty acids. These are now the cheapest source of calories in the world. They have become ubiquitous in the American diet and are spreading worldwide like a virus. The reason for my concern is that omega-6 fatty acids are the building blocks for powerful inflammatory hormones known as eicosanoids. When increasing levels of omega-6 fatty acids in the diet were combined with the increased insulin generated by sugar and other refined carbohydrates, it spawned a massive increase in cellular inflammation worldwide in the past 40 years starting first in America (6). It is this Perfect Nutritional Storm that is rapidly destroying the fabric of the American health- care system.

The bottom line is that the macronutrient balance of the diet will generate incredibly powerful hormonal responses that can be your greatest ally or enemy in controlling cellular inflammation. Unless you feel incredibly lucky, try to stick with the food ingredients that give your genes the best chance to express themselves.


  1. Wells S. “The Journey of Man: A Genetic Odyssey.” Random House. New York, NY (2004)
  2. Kuipers RS, Luxwolda MF, Dijck-Brouwer DA, Eaton SB, Crawford MA, Cordain L, and Muskiet FA. “Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet.” Br J Nutr 104: 1666-1687 (2010)
  3. Sears, B. “The Zone.” Regan Books. New York, NY (1995)
  4. Sears, B. “The OmegaRx Zone.” Regan Books. New York, NY (2002)
  5. Sears, B. “The Anti-Inflammation Zone.” Regan Books. New York, NY (2005)
  6. Sears B. “Toxic Fat.” Thomas Nelson. Nashville, TN (2008)

Nothing contained in this blog is intended to be instructional for medial diagnosis or treatment. If you have a medical concern or issue, please consult your personal physician immediately.

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About Dr. Barry Sears

Dr. Barry Sears is a leading authority on the impact of the diet on hormonal response, genetic expression, and inflammation. A former research scientist at the Boston University School of Medicine and the Massachusetts Institute of Technology, Dr. Sears has dedicated his research efforts over the past 30 years to the study of lipids. He has published more than 30 scientific articles and holds 13 U.S. patents in the areas of intravenous drug delivery systems and hormonal regulation for the treatment of cardiovascular disease. He has also written 13 books, including the New York Times #1 best-seller "The Zone". These books have sold more than 5 million copies in the U.S. and have been translated into 22 different languages.

36 thoughts on “A short history of the human food supply

  1. My wife and I have been following the Zone principles for years and we thank you for all that you have shared with us through your books and articles.

    We “get” that there is a range of values for each macronutrient that depends on each person’s genetic makeup. This means we get more out of your recommendations by fine tuning the implementation until we find what works best for us.

    We also get that the goal is inflammation control and that the more “paleo” we go, the easier it is for our bodies to process the food and avoid inflammation. Since we live in today’s world we also give some leeway to a strict adherence to those kinds of things since it can often be impractical. We find the Zone Diet to be extremely flexible in that regard and we appreciate all the thought and effort you have put in throughout the years to create the guidelines for this way of eating.

    We do have one question regarding recent research that seems to show that saturated fat from grass fed beef, for example, may not be as bad as some other saturated fats that come from factory farms and the like. So called pasture butter (and milk) might fall into that category as well as “forest fed” swine (bacon) and free range eggs. If it turns out to be true, and since your dietary guidelines sprang from evolving science that originally went against established guidelines, do you have any comments on the merits (or dangers) of including butter or pork bacon, etc., from time to time and still remaining true to the anti-inflammatory goals of the zone diet way of eating? The reason we wanted to ask this is because your plan emphasizes low fat things and “good” fats like olive oil, avocado, etc. We trust your integrity on following the science and wanted to get a feel for where you stand on this.


    • All saturated fats have the capacity to interact with Toll-like Receptor 4 (TLR-4) that can initiate activation of cellular inflammation via NF-kB. The benefits of grass-fed beef is that it has lower amounts of omega-6 fatty acids, whereas corn-fed beef has higher amounts of omega-6 fats. The saturated fats in both types of beef will still activate TLR-4 to the same degree, but the grass-fed beef or free range bacon will have a lower inflammatory impact because of the reduction of omega-6 fatty acids. Free range eggs as all eggs will be high in arachidonic acid and therefore even more pro-inflammatory than corn-fed beef.

      Personally, egg whites are my preferred choice for high quality protein, rich in leucine, and totally absent in arachidonic acid and omega-6 fatty acids. A relatively boring protein choice, but a great non-inflammatory protein choice. My other protein choices are primarily lean fish (I add purified fish oil as a supplement), and only occasionally wild game and other free range beef and poultry products if I can find them.

      • Thanks for the information – especially about the high arachidonic acid content of even free range egg yolks.

        We’ve been occasionally feasting lately on free range or grass fed, well, everything…and minimizing the carbs and eliminating processed foods. We like the taste and the satiety, but our focus was on the new idea that this stuff might not lead to clogged arteries and heart disease.

        Your comments about the potential all saturated fats have to “…initiate activation of cellular inflammation…” kind of puts a damper on going whole hog like, for example, this morning’s breakfast:

        2 free range egg omelet with mushrooms, garlic, and grass fed cheese prepared with pasture butter; 5 strips of free range bacon, glass of organic whole grass fed milk, and a small handful of fresh (?) blueberries. (I did have the usual combination of 2 Zone polyphenol capsules plus 6 OmegaRx and 2 EicoRx capsules at least)

        Anyway, thanks for the information and the protein ideas. Who knew the reduced Omega 6 content of grass fed saturated fat was only part of the story? I guess I better study up on the TLR-4 and NF-kB stuff….
        Thanks again

        • Nutrition is complex and becoming more so with new breakthroughs in molecular biology. But this new knowledge allows you to make better dietary decisions for a better quality of life.

          • Ok, so THATexplains why my blood/cholesterol levels were so high when I was on high protein/low carb..mainly grassfed beef, mainly regular eggs, cheese and butter. I lost tons of weight but cholesterol levels were really frightening! So much so that I changed my diet added back whole grains/carbs and krill. Cholesterol is still too high but much lower.
            I have had no good results with adding fish oil(zone or otherwise) to my diet and now it seems it wasn’t the krill helping me either.

  2. Pingback: 3-7-11 « 1592 Fitness

  3. You missed the most recent category. The “Do you feel lucky punk?” genetically engineered foods. This is the classic double edged sword of science. Great potential but great risks and unfortunately there is little to no testing and no long term testing. Since 1994 our food supply has been infused with GMO based foods with little or no controls, testing or long term safety studies.


    I am not a Ludite but I am not a lab rat for Monsanto either!

  4. Hello, Barry. I’ve bought & read your book.

    Regarding legumes: You say that they need denaturing (from their unhealthful quality) by “fermentation or boiling”. I think that should be “sprouting” or “long soaking [to the point of beginning of sprouting] followed by long, slow cooking.”

    And “fermentation” of grain doesn’t have to mean alcoholic fermentation. It can refer to long-raised (18-24 hours) bread, which is wonderful – I can tell the difference. I remember my grandmother leaving her dough to rise overnight.

    While I’m here, I wanted to ask you about the dark orange unrefined palm oil. It’s consumed in Africa. I bought a jar of this stuff to try it out and rather like it. Do you have any comments on this product? Many thanx. – Chicky.

    • Fermentation is well established technique to reduce many of the anti-nutrients found in legumes. Relative to breads, it is a very good method of reducing carbohydrate content as the glucose is fermented into lactic acid as in sourdough bread.

      Unrefined palm oil is rich is polyphenols (that’s why it is red). It’s the polyphenols that give the health benefits to oil such as olive oil (the really good stuff is green).

  5. As usual, a lot of good information to think about. You lay it out so simply and have done all the hard research, what’s left except to choose what works? I really appreciate your blog posts and reading them has been helping me to make better choices and stay more strictly in The Zone. In just a few weeks, my energy has increased and my joints feel better. My appetite, which was amplified by eating sugar and carbs, has decreased and I’m even leaving food on my plate. Being raised by parents who lived through the Depression, this is difficult but no one is being saved from starvation by me cleaning my plate! Old habits die hard but I’m grateful that I have your website and blog to provide support.

  6. Dr. Sears, I appreciate the Zone and have been following along for some time now. I have noticed in some of your articles, as the one above, the mention of thousands of years of exsistence,ie; “190,000 years of co-existence with our genes.” I am in disagreement with you on this. I take a biblical approach to existence believing God created the heavens and earth and man about 6,000 years ago. I enjoy your research developments but find this facet of your research a far-fetched position.

    Sincerely, thanks.

  7. Thank you Dr Sears for your research and for sharing with us your results. I have been living in the zone for the last 8 years – I lost 40lbs the first year and thought I could manage to stay in the zone no matter what. I would like to read and learn about stress and how it affects our carves and /or how it affects how fast we eat… Stress in my life this last months is pulling me out of my healthy habits. I sadly identify with the feeling of “sick, fat, less intelligence etc.. mentioned in your post” and it seems I cannot get back into zone.

    • Dear Mayra. I know you were wanting Dr Sears’ advice and not mine, but I know what you mean. Sometimes, there are situations – as you describe – where, in theory, following a certain way of eating will solve your problem, but what do you if you just can’t follow the diet! Stress does that to us.

      I recommend that you look into a condition referred to as “liver stagnation”. This term is sometimes used by natural medical practitioners as well as doctors of Trad. Chinese medicine. In fact, a TCM doctor told me that I had “liver stagnation”, also known as “liver congestion”. Clearing this biliary sludge out of your liver/gallbladder will likely put you on the right track. Also, heavy emotions (ie, stress) are associated with such clogging of the liver, in traditional/classical Chinese medicine. Best of luck to you!

      • Mayra is saying that she is having trouble staying in the zone because of stress. It is apparently a vicious circle for her. She needs help breaking through. I suggested she look into liver de-congestion. It- liver congestion – is an actual condition that makes it difficult if not impossible to eat healthily.

  8. hi Dr sears, i want thank u for changing my life and make it alot more better, i decided to take it to best way, so im eating only fruits vegetables ckicken and fish nothing else.
    however im loosing to much weight 2 kg in a week, my fat deacresd from 21% to 15%,
    a month ago my weight was 90 now its 82, my height is 1.86 m, im working out one hour a day
    aerobic and unaerobic aswell, by my calculation its: protein 115g, carbohydrate 150g, fat 40g a day.
    any tips?

    • Once you can see your abdominal muscles (usually 10% in males), then you know it is time to start adding more monounsaturated fat to your diet as caloric ballast to maintain your fat at that level. You are doing a great job in reaching that 10% body fat level.

  9. Barry, I noticed that in your list of preferred protein sources you don’t list soy or whey. You were a big soy fan at one point. Did your view change based on some of the science coming out that soy can have harmful effects? Is whey bad because it comes from dairy source?

    • I still strongly believe is soy protein if it is free of isoflavones and other anti-nutrients inherent in crude soy bean as I discussed in The Soy Zone. The isoflavones in particular can bind to the thyroid receptors making it more difficult for thyroid hormones to exert their metabolic actions.

      Whey protein accounts for about 20% of milk protein. It gets rapidly absorbed compared to other protein sources so it can’t stimulate the release of PYY from L-cells in the ileum that leads to satiety. It’s rapid absorption also tends to increase insulin levels faster than other proteins.

  10. Dr.Sears constantly talks about controlling inflammation and that most illnesses are the result of inflammation but nowhere can I find a way to know how much inflammation I have. If anyone strictly follows the Zone diet and takes purified Zone fish oil, how can the person tell if it’s working other than feeling good or not getting ill. This all seems to me to be a guessing game concerning inflammation. I can easily test for cholesterol, blood sugar, hypertension but not inflammation. Last year a biopsy revealed I had aggressive high risk prostate cancer and I sent away to Canada for a $150.00 Inflammation test and it revealed no inflammation. My cancer is now gone after successful radiation treatments but how can I, or anyone, keep an eye on their inflammation besides guessing or paying $150.00 for one test.

    • The best test for cellular inflammation remains the ratio of AA to EPA in the isolated plasma blood. That particular test is relatively expensive. The AA/EPA ratio in the whole blood is less expensive screen for potential inflammation. Measuring for cellular inflammation in the blood still is not perfect predictor just as many people who have normal cholesterol often have fatal heart attacks. Nonetheless, I don’t see any other type of testing in the near future that has more predictive power than that particular test.

  11. I just read the post by itai concerning too much weight and I’m sure of the answer.
    Dr. Sears Zone diet requires you to calculate how many blocks you need to eat every day.
    itai is simply eating too few blocks. You need to recalculate how many blocks you need to maintain your weight.

  12. I also share many of the concerns that are posted here and would like Dr Sears to respond but it seems he is too busy with his zone cruise to alaska.

    • I just returned from speaking at an obesity conference in LA and another conference for treating brain damage in retired NFL players in Las Vegas, hence the tardiness in replying to the some of the comments.

  13. I was told Dr.Sears had planned on having his own lab set up for cellular inflammation testing by the end of 2010. I’m sure this testing should be of the utmost priority above all other priorities.
    Now well into 2011, I am concerned as to why there is no update on this issue.

    • Before you can legally do a blood test, you have to become a CLIA certified diagnostic lab. This is equivalent of a FDA certification of a drug plant and it takes time. Our CLIA inspection takes place in April and we should be introducing a finger stick blood test for measuring the AA/EPA ratio at the American Heart Association in the fall.

  14. The AA/EPA test I had done last summer was a finger prick test. I had to put at least 7 drops of blood from my finger into a vial and mail it to Nutrasource Diagnostics Lab in Canada. The results were emailed to me.

  15. Reading your recommendation for from proteins based on egg s white, what is your opinion on quails eggs, whole and raw?

    • The same would hold true for quail eggs. Eat the whites and throw around the yolks that will be rich in arachidonic acid. You will just need to eat a lot of quail egg whites to provide 30 grams of high quality protein.

  16. If Randy Brown happens to read this, I’d like to ask him how he knows, specifically,
    how he is reducing his inflammation and how he is keeping it under control, as he states,
    and why, Randy, do you take 8 capsules of Omega3 with breakfast? Dr. Sears only recommends 4 if your inflammation is under control. 8 capsules can take your AA/EPA out of balance unless you have a lot of inflammation already. I am puzzled about this. Randy, would you please explain.

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