Epigenetic processes play a central role in regulating the tissue-specific
expression of genes. Alterations in these processes can therefore lead to profound changes
in phenotype and have been implicated in the pathogenesis of many human diseases.
However, there is now evidence that the epigenome is susceptible to a range of
environmental cues such as variations in diet, maternal behaviour or stress during specific
developmental periods. The environmental sensitivity of the epigenome has been suggested
to reflect an adaptive mechanism, by which the organism can adjust its metabolism and
homeostatic systems to suit the environment, in order to aid survival or reproductive
success in later life. Inappropriate adaptation has been linked to the development of a range
of chronic diseases in later life and has been suggested to account for at least some of the
rapid increases in the rates of obesity, type II diabetes and cardiovascular disease recently
observed in both developed and developing countries. This chapter will therefore focus on
how nutritional cues in the environment can alter the epigenome, producing different
phenotypes and altered disease susceptibilities from a single genotype.
Keywords: Epigenetics, nutrition, early life environment, DNA methylation,
obesity, PPARS, adult onset disease, demethylases, transgenerational transmission
developmental plasticity, mismatch.
