The role of diet as a contributing factor in controlling global DNA

Taken together, epigenetic mechanisms elucidate the ability of certain chemical compounds to initiate biological perturbations that can lead to malignancy. This presents challenges and opens new avenues in public health (Stein, 2012).

Another identified environmental factor that influences the epigenetic modifications is the nutritional factor which emerges as an important player in the interaction between the environment and epigenetics. Dietary requirements have possible effects on DNA methylation and gene expression programming (Niculescu and Zeisel, 2002; Poirier, 2002). It is well known that DNA methylation influences the expression of some genes and depends upon the availability of methyl groups from S-adenosylmethionine (SAM). In this regard, dietary components could affect cellular signaling pathways that deliver chromatin-modifying enzymes to specific sequences (McGowan, Meaney and Szyf, 2008).

For instance, diets deficient in nutrients important for the epigenetic metabolism like folate, choline and methionine are related to DNA methalations alterations, development of mental disorders (McGowan, Meaney, and Szyf, 2008) and an increased risk of developing atherosclerosis, neurological disorders and birth defects (Poirier, 2002).

The role of diet as a contributing factor in controlling global DNA methylation status has been best illustrated in adult males suffering from uremia and undergoing hemodylasis. These patients experience hyper-homocysteinaemia due to low methionine content as a result of folate depletion. Researchers found that these patients have reduced global and locus-specific DNA methylation. This was reversed after the administration of high doses of folic acid (Ingrosso et al., 2003).

In another study, Williams et al. (2006) conducted a study to investigate the effect of moderate alcohol intake on bone mineral density and fracture risk in 46 pairs of monozygotic twins discordant for alcohol consumption while controlling genetic effects and other confounding variables. Their results revealed a positive association between alcohol consumption and bone mineral density. They concluded that moderate alcohol consumption is not harmful to bone health in women and may even be beneficial (Williams et al., 2006)