Believe it or not, our DNA is almost exactly the same as that of our ancestors. While scientific advances in agriculture, medicine, and technology have protected man, to some degree, from dangers such as starvation, illness, and exposure, the fact remains that our cave-dwelling cousins were considerably healthier than we are. Our paleolithic ancestors did not suffer from heart disease, diabetes, high blood pressure, or obesity. In fact, a good deal of what we view as normal aging is a modern condition that is more akin to disease than any natural state of growing older.

Our...