Epigenetics is the study of how environmental and lifestyle factors influence the expression of our genes. Think of it this way... you are born with a pre-programmed  set of genes, but variables in your life (from fetal development onward) impact whether these genes are switched "on" or "off". This complex pattern of switches is known as your epigenome. People are very quick these days to dismiss their health problems as "bad genetics" as if their health is 100% pre-determined and completely out of their direct control. But science is now discovering quite the opposite. Everything from what your mother ate, to what you eat, to environmental toxins, to how much sleep you get can influence whether your genes work with you or against you.

Watch this great NOVA Video on Epigenetics.

So if our genetic outcome varies from generation to generation, why do we care what cavemen ate 100,000 years ago? The short answer is that we optimize the control of our genes by mimicking the circumstances under which we evolved for 99% of human existence - paleo food, periods without food, high intensity functional movement, plenty of rest, etc.

This question was addressed in this week's Paleo Diet Newsletter (it's free... you should subscribe!). Consider this the detailed answer...

Q: What do you think about epigenetics? Many scientists (in Germany) believe that the concept of the Paleo Diet is no longer tenable.

Thanks a lot, Michael

A: Dear Michael,
Epigenetics is defined as the science studying changes in phenotype or gene expression by mechanisms other than changes in DNA nucleotide sequence1. The phenotype is someone's appearance which it's determined by the genotype (stable and heritable) and the environment (nutrition and other lifestyle factors) which give place to the epigenotype (heritable, labile and rapid)1. Epigenetic changes are controlled, among other mechanisms, by methylation and histone modification. Altered methylation pattern and histone modification may lead to increased susceptibility to disease. E.G. cancer is associated to generalized hypomethylation and localized promoters hypermethylation1. Histone manipulation may also increase or decrease disease susceptibility2.

Both, methylation and histone manipulation are under the control of dietary substances. For example, methylation depends on SAMe availability, which in turn is influenced by vitamin B6, vitamin B12 and folate intake3, and long chain polyunsaturated fatty acids such as DHA4. On the other hand, certain substances such as garlic, horseradish, fiber, blueberries, apple, onion, nuts, berries, red grapes, broccoli, etc. are known nutrients involved in histone modification2.

The Paleo Diet is rich is all of these nutrients5, hence it may exert positive effects upon epigenetics machinery leading to decreased disease susceptibility. Decreased availability of micronutrients is associated to disease severity, probably, through complex epigenetic mechanisms, and supplementation could improve those symptoms3. Improved epigenetic is influenced by metabolic programming during foetal and early life. These two periods are crucial for the developing newborn and future adult's health. Hence, The Paleo Diet may confer protection against several diseases improving the epigenetic programming.
We hope this is helpful.

Maelán Fontes Villalba
Pedro Carrera Bastos

References:
¹ van Vliet J, Oates NA, Whitelaw E. Epigenetic mechanisms in the context of complex diseases. Cell Mol Life Sci. 2007 Jun;64(12):1531-8.
² Delage B, Dashwood RH. Dietary manipulation of histone structure and function. Annu Rev Nutr. 2008;28:347-66.
³ Kemperman RF, Veurink M, van der Wal T, Knegtering H, Bruggeman R, Fokkema MR, Kema IP, Korf J, Muskiet FA. Low essential fatty acid and B-vitamin status in a subgroup of patients with schizophrenia and its response to dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 2006 Feb;74(2):75-85.
⁴ Muskiet FA, Kemperman RF. Folate and long-chain polyunsaturated fatty acids in psychiatric disease. J Nutr Biochem. 2006 Nov;17(11):717-27.
⁵ Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O'Keefe JH, Brand-Miller J. Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr. 2005 Feb;81(2):341-54.
⁶ Kemperman RF, Veurink M, van der Wal T, Knegtering H, Bruggeman R, Fokkema MR, Kema IP, Korf J, Muskiet FA. Low essential fatty acid and B-vitamin status in a subgroup of patients with schizophrenia and its response to dietary supplementation. Prostaglandins Leukot Essent Fatty Acids. 2006 Feb;74(2):75-85.