Diet and Epigenetics

Abstract

1. Diet and dietary factors are important contributing factors to health and disease. Since an inappropriate diet may contribute significantly to the causation of chronic disease, including cancer, it is important to uncover the molecular mechanisms of dietary bioactive factors in health and disease in order to determine the best strategies for intervention. 2. Evidence suggests that diet and other environmental factors may be significant regulators of epigenetic events, including DNA methylation, histone posttranslational modification, noncoding RNAs, and factors/proteins that regulate chromatin structure and dynamics. 3. At least four ways in which nutrients may be interrelated with DNA methylation have been found. First, nutrients may influence the supply of methyl groups for the formation of S-adenosylmethionine (SAM). Second, nutrients may modify the utilization of methyl groups by DNA methyltransferases. A third possible mechanism may relate to DNA demethylation activity. Fourth, the DNA methylation patterns may influence the response to a nutrient. 4. One example of the influence of diet in DNA methylation and cancer is the finding that dietary methyl deficiency (of folate, choline, or methionine) has been shown to alter hepatic DNA methylation patterns and induce hepatocarcinogenesis in the absence of a carcinogen in Fisher 344 rats. 5. Although the cancer epigenetic field has advanced in the last decade, much remains to be revealed especially with respect to potential modification by bioactive dietary components. Research needs to address the quantity of dietary components needed to bring about a biological effect, the effects of timing of exposure, and how chemical form and duration of exposure influence the cancer process.