though controversy exists as to the precise role of diet in cancer prevention, there is little doubt that a prudent approach to dietary intake may help reduce the risk of cancer morbidity and mortality.Differing estimates of the contribution of diet to cancer have emerged. Wynder and Gori (1977) estimated that as many as 40% of cases of cancer were associated with diet, while Doll and Pet0 (1981) suggested that a range of 20-90% of cancer deaths were related to diet. The National Academy of Sciences has asserted that most cancers are related to dietary intake (National Research Council, 1989). Specifically, in countries where fat intake is 20% or less of total caloric intake, the rates of both breast and colon cancer are lower than in the United States (Prentice & Sheppard, 1990; Rose, Boyar, & Wynder, 1986). In the United States, the average fat intake is 34% of total calories (McDowell et al., 1994).Similarly, cancer rates are lower in countries where complex carbohydrates contribute to the majority of calories (Liu et al., 1979;Phillip, 1975) and total dietary fiber is more than double that of the United States (i.e., 25-30 g vs. 13-15 g per day; Carroll, Abraham, & Dresser, 1983; National Research Council, 1989). Studies have shown a protective effect of fiber from vegetables, especially green vegetables (Hu et al., 1991), and fruits and grains (Giovannucci, Stampfer, Colditz, Rimm, & Willett, 1992). Decreases in stomach cancer have been documented in populations with increased intake of fruits and vegetables (Miller et al., 1994). Studies in the United States and China have shown fruit and vegetable consumption to have a protective effect against oral and pharynx cancers (McLaughlin et al., 1988;Zheng et al., 1992).Comparisons of genetically similar populations residing in the United States and non-Western countries have revealed higher cancer rates in the United States. Data show that second-and third-generation Japanese women born on the U.S. mainland have breast cancer rates comparable to those of U.S. women and higher than those of Japanese women born and living in Japan