Introduction

The interaction of genetics and environment, nature, and nurture is the foundation for all health and disease. This concept, based on molecular biology and genetics, was originally defined by Hippocrates. In the 5th century bc, Hippocrates stated the concept of positive health as follows:

Positive health requires a knowledge of man's primary constitution [which today we call genetics] and of the powers of various foods, both those natural to them and those resulting from human skill [today's processedfood]. But eating alone is not enough for health. There must also be exercise, of which the effects must likewise be known. The combination of these two things makes regimen, when proper attention is given to the season of the year, the changes of the winds, the age of the individual and the situation of his home. If there is any deficiency in food or exercise the body will fall sick.

In the last two decades, using the techniques of molecular biology, it has been shown that genetic factors determine susceptibility to disease and environmental factors determine which genetically susceptible individuals will be affected (Simopoulos and Childs, 1990; Simopoulos and Nestel, 1997; Simopoulos, 1999d). Nutrition is an environmental factor of major importance. Whereas major changes have taken place in our diet over the past 10,000 yr since the beginning of the Agricultural Revolution, our genes have not changed. The spontaneous mutation rate for nuclear DNA is estimated at 0.5% per million years. Therefore, over the past 10,000 yr there has been time for very little change in our genes, perhaps 0.005%. In fact, our genes today are very similar to the genes of our ancestors during the Paleolithic period 40,000 yr ago, at which time our genetic profile was established (Eaton and Konner, 1985). Genetically speaking, humans today live in a nutritional environment that differs from that for which our genetic constitution was selected. Studies on the evolutionary aspects of diet indicate that major changes have taken place in our diet, particularly in the type and amount of essential fatty acids (EFA) and in the antioxidant content of foods (Eaton and Konner, 1985; Simopoulos, 1991; Simopoulos, 1999a; Simopoulos, 1999c) (Table 1, Fig. 1). Using the tools of molecular biology and genetics, research is defining the mechanisms by which genes influence nutrient absorption, metabolism and excretion, taste perception, and degree of satiation, and the mechanisms by which nutrients influence gene expression.

From: Fatty Acids: Physiological and Behavioral Functions Edited by: D. Mostofsky, S. Yehuda, and N. Salem Jr. © Humana Press Inc., Totowa, NJ

Table 1

Characteristics of Hunter—Gatherer and Western Diet and Lifestyles

Hunter-Gatherer Western

Table 1

Characteristics of Hunter—Gatherer and Western Diet and Lifestyles

Hunter-Gatherer Western

Characteristic

diet and lifestyle

diet and lifestyle

Physical activity level

High

Low

Diet

0 0

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