Healthy Intentions

Our genes evolved to work in an environment of a hunter-gathering diet. Although adaptation has continued, at least one hundred thousand generations of people were hunter-gatherers; only five hundred generations have depended on agriculture, only ten generations have lived since the onset of the industrial age, and only two generations have grown up with highly processed fast foods. There has simply not been time for our bodies to adapt to such a dramatic change. Physicians Randolph Nesse and George Williams write: "Our bodies were designed over the course of millions of years for lives spent in small groups hunting and gathering on the plains of Africa. Natural selection has not had time to revise our bodies for coping with fatty diets, automobiles, drugs, artificial lights, and central heating. From this mismatch between our design and our environment arises much, perhaps most, preventable modern disease."

Do we really want to eat like prehistoric humans? Surely "cavemen" were not healthy. Surely life was hard and short. Apparently not. Archaeological evidence indicates that these hunter-gatherer ancestors were robust, strong, and lean, with no sign of osteoporosis or arthritis-even at older ages.

DNA Molecule

Paleolithic humans ate a diet similar to that of wild chimpanzees and gorillas: fresh raw fruit, nuts, seeds, vegetation, fresh untreated water, insects, and wild-game meat low in saturated fats. Much of their food was hard and bitter. Most important, like chimpanzees and gorillas, prehistoric humans ate a wide variety of plants-an es- timated one hundred to three hundred different types in one year. Nowadays, even health-conscious Westerners seldom consume more than twenty to thirty different species of plants. A broad range of plants provides not only essential vitamins and minerals but also valuable secondary plant compounds integral to preventive and curative medicine.

The early human diet is estimated to have included more than 100 grams of fiber a day. Today the recommended level of 30 grams is rarely achieved by most of us. Humans and lowland gorillas share similar digestive tracts-in particular, the colon-but while gorillas derive up to 60 percent of their total energy from fiber fermentation in the colon, modern humans get only about 4 percent. When gorillas are brought into captivity and fed on lower-fiber diets containing meat and eggs, they suffer from many common human disorders: cardiovascular disease, ulcerative colitis, and high cholesterol levels. Their natural diet, rich in antioxidants and fiber, apparently prevents these diseases in the wild, suggesting that such a diet may have serious implications for our own health.