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.

References

  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.

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