281 Whole grain intake and chronic disease: Defining the impact.

David R. Jacobs, Jr., PhD (1), Mark A. Pereira, PhD (1), Joanne Slavin, PhD, (2), and Leonard Marquart, PhD (3). (1) Division of Epidemiology, School of Public Health, University of Minnesota; (2) Department of Food Science and Nutrition, University of Minnesota; (3) General Mills, Inc.

Epidemiologic studies support the Burkitt Hypothesis that a diet high in whole grains and other whole plant foods reduces risk for diseases common in developed countries. In nearly 40,000 Iowa women aged 55–69, followed for 10 years, those who reported habitual consumption of whole grain foods had 15–25% lower relative risk of total mortality, independent of other lifestyle and dietary behaviors. In line with the Burkitt Hypothesis, there were fewer coronary heart disease deaths, but not enough to fully account for fewer total deaths, suggesting that risk of other chronic diseases is also lower in whole grain eaters. A review of 40 case-control studies of high versus low intake of whole grain found reduced risk in 90% of studies of 18 cancers and colon polyps; findings were equivocal only for breast and prostate. A recent observational study suggests that habitual whole-grain eaters have lower fasting serum insulin, which may contribute to reduced coronary heart disease risk. Overall the existing prospective and case-control epidemiologic evidence supports the hypothesis that whole-grain intake is associated with lower risk of coronary heart disease and various types of cancer. This lower risk may well be caused by whole grain intake through mechanisms such as reduced insulin resistance and decreased oxidative stress, because whole grains contain nutrient-rich fiber, including minerals, vitamins, phenols, and phytoestrogens. Further research clarifying the biologically active constituents of whole grain is needed. Even in the absence of such research, prudence calls for increased whole grain consumption.