You are what you eat, the saying goes. And, according to two new genetic studies, you are what your mother, father, grandparents and great-grandparents ate, too.
Diet, be it poor or healthy, can so alter the nature of one’s DNA that those changes can be passed on to the progeny. While this much has been speculated for years, researchers in two independent studies have found ways in which this likely is happening.
The findings, which involve epigenetics, may help explain the increased genetic risk that children face compared to their parents for diseases such as obesity and diabetes.
Epigenetics refers to changes in gene expression from outside forces. Different from a mutation, epigenetic changes lie not in the DNA itself but rather in its surroundings — the enzymes and other chemicals that orchestrate how a DNA molecule unwinds its various sections to make proteins or even new cells.
Recent studies have shown how nutrition dramatically alters the health and appearance of otherwise identical mice. A group led by Randy Jirtle of Duke University demonstrated how mouse clones implanted as embryos in separate mothers will have radical differences in fur color, weight, and risk for chronic diseases depending on what that mother was fed during pregnancy.
That is, the nutrients or lack of thereof changed the DNA environment in such a way that the identical DNA in these mouse clones expressed itself in very different ways.
Of mice and humans
Building upon this Duke University work, a new study led by Torsten Plosch of University of Groningen, The Netherlands, delineated the numerous ways in which nutrition alters the epigenome of many animals, including adult humans. The paper has been submitted to the journal Biochimie with lead author Josep C. Jimenez-Chillarón of the Paediatric Hospital Sant Joan de Deu, in Spain.
The researchers said that the diet of human adults induces changes in all cells — even sperm and egg cells — and that these changes can be passed on to offspring.