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Although many medical conditions are the result of gene mutations that have passed from generation to generation, evidence is mounting that the environment can not only have an impact on personal health but can also be conserved in the genes. These environmental “shocks” seem to be capable of leaving an imprint on the genetic material in eggs and sperm, which can pass along new traits in a single generation.

The epigenome sits above the DNA sequence and provides a second layer of information, regulating several genomic functions, including when and where genes are turned on or off. New studies have shown that so‐called epigenetic marks are associated with genes, providing instructions such as telling them to switch on or off. These marks are normal and allow cells to differentiate, but if the marks do not work properly because of an environmental stressor, cancer or cell death might result, and, worst of all, could be transmitted to descendants. So, if some stressor such as a rich diet activates an epigenetic mark, which in turn modifies histones or adds methyl groups to DNA strands, it could result in disease or susceptibility to disease that not only affects the individual but can be passed on to future generations. This epigenetic influence may not even occur equally across both alleles, in some instances depending on genotype and in other instances depending on from which parent the allele was inherited. Nutrition is likely a major factor in epigenetics, and technological advances will likely lead to the identification of nutrient‐responsive genes and biological pathways, important nutrient–gene interactions, and genomic biomarkers of disease [1].

While perhaps not as well known and discussed as the genome, the epigenome is believed to be much larger and more complicated than the genome of 20 000 or so genes. Medications are even available now that exert their effects through epigenetic marks. These developments are bound to assume more significance in the years ahead.