Epigenetics stands among many sets of biological mechanisms that may be useful to researchers working in public health. It may be specifically interesting because:
- It is a set of upstream intracellular biological mechanisms that may be environmentally driven
- It affects gene expression
- It potentially affects many downstream biological systems
- It may offer plausible explanations about why genetics appears to explain so little about health & disease
- It may be heritable (‘environmental’ intergenerational transmissions)
- It may be reversible (interventions?)
What is epigenetics?
Epigenetics is fashionable in epidemiology, and the vocabulary surrounding it is now passing into popular culture. I have seen it mentioned in self-help pamphlets and advice on general health to the public.
Here is a definition of epigenetics we used in a paper:
Epigenetics refers to any information heritable during cell division other than the DNA sequence itself (Feinberg 2007). McGowan and Szyf (2010) have used the following definition ‘‘the combination of mechanisms that confer long-term programming to genes and could bring about a change in gene function without changing gene sequence’’ (McGowan and Szyf 2010). The most well-established epigenetic methylation modification has been observed whereby a methyl group is added to DNA. Methylation of critical regulatory regions affects gene expression, hypermethylation is usually associated with the silencing of genes whereas hypomethylation with gene activation. This alteration can be stable, and long-term but also reversible due to the existence of DNA demethylases. Epigenetic processes are therefore essential for understanding gene function and expression (Hochberg et al. 2011).