Brain Food, Part 2

The Protein Power LifePlan
by Michael R. Eades, M.D., Mary Dan Eades, M.D.

(Page 4 of 4)

Our primitive ancestors, whether hunters or hunter-gatherers, by all accounts lived fairly prosperous lives, at least by their standards. They lived in small, closely knit groups, and compared to the early farmers that followed them, they had much better health, greater stature, more children reaching maturity, and a longer life span. Turning to an agricultural existence forced the reliance on fewer numbers of foods, and since no single plant food provides a full complement of all the nutrients humans need, many people suffered nutritional deficiencies. And if the crop failed, famine set in-an experience foreign to most of the hunter-gatherer populations because they were always on the move, traveling to where there were plenty of game and fertile fields for gathering. A system in which large groups of people lived in close proximity, at least where early man was concerned, wasn't really all that advantageous. Most of the infectious diseases that have caused so much misery throughout history-smallpox, cholera, tuberculosis, and a host of other bacterial and viral infections-became problems only after the advent of the agriculture and the development of cities. All this begs the question, why did humans ever settle down and become civilized? Why did they leave their Garden of Eden, give up their hunting jobs requiring only a few hours of work per day, and submit to the backbreaking toil of an agricultural life? It just doesn't make sense.

This question has been pondered ever since anthropologists figured out that humans made this transition, and, as you might expect, almost as many hypotheses have been forwarded as there are anthropologists. Greg Wadley and Angus Martin, researchers at the University of Melbourne in Australia have put forth an engaging theory that makes a lot of sense to us. They point out that there exists a considerable amount of research establishing the fact that cereal grains, especially wheat, maize, and barley and, to a slight extent, dairy products contain opioid substances called exorphins. Opioid substances are those that have an opium-like effect, stimulate the opioid receptors in the brain, and are to varying degrees addictive. When bands of primitive people stumbled onto patches of wild grains and consumed them they discovered the reward from consuming “addictive” substances, i.e., comfort foods. People quickly developed ways of making these foods even more edible by grinding and cooking them. As the grains become more palatable through processing, the more they were consumed and the more important the exorphin reward became.

In the words of Wadley and Martin, “At first, patches of wild cereals were protected and harvested. Later, land was cleared and seeds were planted and tended, to increase quantity and reliability of supply. Exorphins attracted people to settle around cereal patches, abandoning their nomadic lifestyle, and allowed them to display tolerance instead of aggression as population densities rose in these new conditions.” According to these researchers, then, grains were the first opiate of the masses!

Whether this theory is the correct one or not, there is no question in our minds that carbohydrate foods cause cravings and are, to a certain degree, addictive, particularly those of cereal grain origin. If you look at any list of the top ten foods consumed by Americans you will find bread, crackers, chips, breakfast cereals, and other high-carbohydrate, grain-based products. We have all experienced the addictive nature of carbohydrates and their ability to override the feeling of fullness. Think back to the last time you were at a restaurant or at someone's house for dinner and you ate until you were stuffed. If one of your dinner mates asked you to try just a bite of the delicious swordfish (or any other meat dish), you no doubt begged off, saying, “I'm just too full; I couldn't possibly eat another bite.” But then, if your host or your waiter arrived bearing dessert, you probably said, “Oh, well, dessert, sure. I'll have some cake”-or ice cream, or tiramisu, or cobber, or whatever. You are able to eat the dessert, which is always rich in carbohydrates, because just the thought of the carbohydrates overrides your brain signals telling you that you're full. Carbohydrates seem to trigger no off switch. That's why people who binge always do so on carbohydrates. No one binges on steak or eggs or pork chops; they always binge on cookies and candies and other carbohydrate junk foods. Having taken care of as many carbohydrate junkies as we have over the past fifteen years, it is clear to us that cereal grains and products made from them have an allure that transcends the mere taste bud stimulation they provoke. As Wadley and Martin point out, “The ingestion of cereals and milk, in normal modern dietary amounts by normal humans, activates reward centres in the brain. Foods that were common in the diet before agriculture . . . do not have this pharmacological property. The effects of exorphins are qualitatively the same as those produced by other opioid . . . drugs, that is, reward, motivation, reduction of anxiety, a sense of well-being [i.e., comfort foods], and perhaps even addiction. Though the effects of a typical meal are quantitatively less than those of doses of those drugs, most modern humans experience them several times a day, every day of their adult lives.”

It should be clear by now that whichever way you look at it, the majority of our time as humans or our sort-of-human predecessors on this earth has been spent eating meat. The adoption of agriculture with its dependence on a grain-based diet is a recent phenomenon, in fact just a second in evolutionary time. The forces of natural selection haven't yet had anywhere near the time necessary to mold us to function optimally on a grain-based diet. We are still operating with forty-thousand-to-one-hundred-thousand-year-old biochemistry and physiology. Geneticists have evaluated the DNA sequences of humans and our closest relatives, the chimpanzee, and found the difference to be a mere 1.6 percent of genes, meaning we have 98.4 percent of genes in common with chimpanzees. By determining the rate of genetic change since we split away from chimpanzees, scientists have been able to calculate the rate of genetic mutation in humans, which turns out to be on the order of about a half a percent per million years. That means that over the past ten thousand years-the time since the advent of agriculture-we have changed genetically to the tune of about 0.005 percent. That's not much at all. In fact, that means that we have 99.995 percent of our genes identical with those of our big game-hunting ancestors. We are they. We have Fred Flintstone bodies living in a George Jetson world. And therein lies the root of our problems.

In our medical/nutritional practice we view modern diseases in our patients through the lens of their Paleolithic ancestry and use the Paleolithic diet and lifestyle with some twentieth-century modifications as a template to restore their health. (Throughout this book, we'll hold up that lens to the Paleolithic world to give you a look at where and how your modern lifestyle and diet may conflict with it.) We care for patients who have heart disease, elevated cholesterol and triglyceride levels, diabetes, obesity, high blood pressure, gastroesophageal reflux, various autoimmune disorders, and a number of other problems by using a protein-based diet containing a fair amount of meat. Patients are constantly amazed at how quickly they improve and often believe that it is nothing short of miraculous. The reality is that we are just getting them to follow a diet they were intended to eat. We were designed to function optimally on a particular diet, we stray from this diet, we develop disease, we return to the correct diet, and the disease disappears. It's basically as simple as that.

One of the primary ways in which a Paleolithic nutritional regimen works to resolve these problems is by lowering insulin levels. Virtually every food our prehistoric ancestors had available (with the exception of honey) is one that doesn't stimulate the body to produce much insulin, whereas the vast majority of foods we eat in today's world do just the opposite and send insulin levels through the roof. In the next chapter we'll take a look at this most powerful of our metabolic hormones and learn the havoc it can wreak when we stray from our ancestral bill of fare.

Bottom Line

The overwhelming mass of scientific evidence supports the notion that for most of our time on earth, humans and their pre-human ancestors have eaten meat. By all reputable scientific accounts, we've been hunting and gathering (with heavy reliance on the hunting) for the better part of three million years. Eons of natural selection and human development molded our metabolic machinery to succeed on this ancient dietary scheme that appears to have included about 65 percent foods of animal origin and about 35 percent foods of plant origin. Only about ten thousand years ago (at most) did we settle down to cultivate grains and begin to include them as food in our diets. The metabolic changes necessary for humans to adapt to this dietary change-in short, to be able to use these “new” foods well-would reasonably take a few thousand generations (or about forty thousand or fifty thousand years). We're simply not there yet-and won't be anytime soon.

Turning to the use of grains allowed humans to settle in large cooperative groups necessary to build great civilizations, but at a price to the individual members of the group. While we can subsist on grain-based diets, we don't as a species thrive on them; the fossil record shows that after the adoption of agriculture human health, stature, and longevity went into sharp decline. In the last century in the Western world, thanks to a general increase in dietary protein, we've begun to recover our stature, but because of our continued heavy reliance on cereal grains, metabolic health still lags. We're riddled as a society with epidemics of diabetes, high blood pressure, heart disease, and obesity, all of which we inherited when our ancient ancestors abandoned their successful hunting-and-gathering lifestyle in favor of the addictive lure of grains (components of which indeed do stimulate the narcotic centers of the human brain).

In our medical/nutritional practice, we care for people with all components of this epidemic of modern diseases. To restore their health, we advocate a return to the basic nutritional principles of our ancestral hunting-gathering lifestyle by prescribing a diet of nutrient-dense foods-meat, fish, and poultry, rich in protein and good-quality essential fats; fruits, berries, and vegetables, rich in antioxidants and cancer-fighting substances-and limiting what early humans never knew existed-grains, refined sugars, and other concentrated starches.

About the Author

Michael R. Eades, M.D., and Mary Dan Eades, M.D. pioneered the field of metabolic medicine. They are on the faculty of Colorado State University in the Department of Health and Exercise Science. They are the authors of Protein Power/i>, which sold over 3 million copies and spent 63 weeks on the New York Times bestseller list, and The Protein Power Lifeplan. Michael R. Eades, M.D. received his engineering degree from California State Polytechnic University and his medical degree from the University of Arkansas. Along with his wife, he has been in the exclusive private practice of bariatric (weight loss) and nutritional medicine for the last 10 years.

More by Michael R. Eades, M.D.

Mary Dan Eades, M.D. received her undergraduate degree in biology and chemistry as well as her medical degree from the University of Arkansas. She joined her husband in the exclusive practice of bariatric and nutritional medicine in 1992, having previously practiced family and general medicine.

More by Mary Dan Eades, M.D.