Scientists at the University of Massachusetts Medical School and the University of Texas at Austin have found that environmental influences experienced by a father can be passed down to the next generation, “reprogramming” how genes function in offspring. The study shows that environmental cues – in this case, diet – influence genes in mammals from one generation to the next, evidence that until now has been sparse. These insights, coupled with previous human epidemiological studies, suggest that paternal environmental effects may play a more important role in complex diseases such as diabetes and heart disease than previously believed. The human genome is often described as the set of instructions that govern the development and functioning of life. It’s not surprising, then, that most contemporary genetic research focuses on understanding and cataloging how mutations and changes to our DNA-the basis of those “instructions”-cause disease and impact health. To test their hypothesis that environmental influences experienced by the father can be passed down to the next generation in the form of changed epigenetic information, scientists fed different diets to two groups of male mice. The first group received a standard diet, while the second received a low-protein diet. To control for maternal influences, all females were fed the same, standard diet. The scientists observed that offspring of the mice fed the low-protein diet exhibited a marked increase in the genes responsible for lipid and cholesterol synthesis in comparison to offspring of the control group fed the standard diet. These observations are consistent with epidemiological data from two well-known human studies suggesting that parental diet has an effect on the health of offspring. One of these studies, called the Verkalix Cohort Study, conducted among residents of an isolated community in the far northeast of Sweden, found that poor diet during the paternal grandfather’s adolescence increased the risk of diabetes, obesity and cardiovascular disease in second-generation offspring.