If someone’s parents ate a poor diet, does that mean their children are at risk for obesity and diabetes, even if they stick to eating kale and oatmeal? Apparently, yes. How about if they are super disciplined about exercising? The deck is still be stacked against them. Why? Because obesity and diabetes can be epigenetically inherited. Epigenetics is the study of how our heredity interacts with environmental factors and lifestyle. Epigenetic inheritance acts like a light switch to activate or deactivate parts of our genetic information, the “hard code” on our DNA.
Let’s look at a study that suggest how this works. Scientists at Helmholtz Zentrum Munchen, in collaboration with researchers from the Technical University of Munich and the German Center for Diabetes Research, were working with mice. They had mice that had been fed an unhealthy, high-fat diet, and had subsequently become obese. These heavy mice had offspring borne via in vitro fertilization using healthy-weight surrogate mice mamas. The researchers wanted to observe what kind of epigenetic information was passed on to the offspring, separate from the influences of gestation and lactation.
Both the egg cells from the mother mice and the sperm cells from the father mice passed on epigenetic information, the researchers found, “which particularly in the female offspring led to severe obesity,” wrote Professor Johannes Beckers, who directed the study. “In the male offspring, by contrast, the blood glucose level was more affected than in the female siblings.” So both genders of mice offspring were affected by their parents’ high-fat diets, though in different ways.
“This kind of epigenetic inheritance of a metabolic disorder due to an unhealthy diet could be another major cause for the dramatic global increase in the prevalence of diabetes since the 1960s,” wrote Martin Hrabe de Angelis, director of the Institute of Experimental Genetics and initiator of the study. The huge surge in the number of diabetes patients worldwide can’t be explained by the mutations in humans’ genes (DNA) because the change has been so rapid. But epigenetic inheritance could explain such a fast change. On the plus side, the study notes that epigenetic inheritance is in principle reversible, leading to new possibilities to think about how we can tackle the obesity and diabetes epidemics.
Kathryn Drury Wagner is a writer and editor based in Los Angeles. Her latest book is Hawaii’s Strangest, Ickiest, Wildest Book Ever!