Nutrition, epigenetics and health through life

Epigenetics describe heritable changes to the genome without changes to the DNA sequence itself. Epigenetic marks include DNA methylation and histone modifications, and epigenetic molecules include microRNAs. Epigenetic mechanisms modulate gene expression and so regulate many cellular processes such as cell proliferation and cell death. As a consequence, changes to the epigenome may have consequences for the function of cells, tissues and organs and may modify the risk of developing disease. Epigenetic marks and molecules change during development and also during ageing; as we age, global DNA methylation declines whilst some specific genes become hypermethylated. Unlike the genome (DNA sequence), the epigenome is not fixed and the constellation of epigenetic marks and molecules is influenced by environmental exposures, including diet. Therefore, epigenetics provides a mechanism though which nutrition modulates health and wellbeing throughout the life course and, importantly, a plausible mechanism for the long-term effects of early life nutritional exposures. There is growing evidence of the specific nutrients and other food constituents that influence the epigenome but, to date, the molecular pathways through which nutritional exposures and status are transduced (received and recorded) remain to be elucidated. Epigenetic patterns are promising candidate diet-related biomarkers of ageing and of disease risk and, therefore, may be useful as surrogate endpoints in nutritional epidemiology and in dietary intervention studies.