The importance of diets and epigenetics in cancer prevention: a hope and promise for the future?

ABSTRACT

Although it is impossible to fathom innumerable differences in environmental, lifestyle, and socioeconomic differences in populations globally, one element that unequivocally stands out is the striking "dietary" differences between these regions versus those in developed countries, where the staple diet is primarily based on some variation of a conventional Western diet. It is hard to dismiss the overwhelming body of large-scale epidemiological data, adjusted for key variables, which clearly highlights that dietary differences alone can help account for some of the disease disparity witnessed worldwide. The classic view of cancer initiation is that cancer results from alterations in our genome, which closely associates with the dynamics of gene expression that occurs between oncogenes (cancer-promoting genes) and tumor suppressor genes (cancer-inhibitory genes). Interestingly, scientific research for the last few decades has now clearly revealed that alterations in the expression of these genes is rarely manifested by the "genetic" events themselves, and that only approximately 2% to 5% of the majority of cancers, particularly colorectal cancers, are driven by germline mutations (which can be hereditarily passed onto subsequent generations) in cancer-related genes. In only the last decade, we have recognized that expression of cancer-associated genes in the majority of sporadic cancers is actually controlled by a unique process, defined as epigenetics-a process that can influence gene expression, without causing a permanent alteration in a gene (or DNA). Such epigenetic alterations can occur in a heritable manner, are not permanent (hence reversible), and can be easily modified by dietary and environmental stimuli. Epigenetics helps us understand that genetic or hereditary forms of most cancers are extremely rare and that most cancers can be realistically prevented or managed by making simple day-to-day changes in our diets.