Stress During Pregnancy May Imprint Baby’s Genes
New research done at the University of Minnesota and Georgetown University suggests that a mother’s stress during pregnancy imprints the genetic makeup of the baby, making that baby more likely to develop obesity later in life. The research team stressed pregnant mice. After the babies were born, the females developed fat around their middle and prediabetes symptoms. The males did not. The team believes this is a result of a changed metabolism due to the mother’s stress.
The team continued their study by exposing cells in a test tube to stress hormones during their development. They found that cells exposed to these hormones at a certain time in their embryonic development would “remember” their cell type, and be inclined to become fat cells. The team believes this indicates that stress hormones of the mother will cause genetic changes in the fetus, making the fetus prone to metabolic syndrome and obesity.
The female mice in this study developed this obesity response, but the males did not. This could be because neuroscientists find that men and women respond differently to stress. In men, stress activates the “fight or flight” response, but in women, it activates the limbic system. The limbic system is associated with emotional response. Overeating in response to emotional stimuli is often at the core of obesity problems.
If these experimental results in mice prove true in humans, they could help to overcome the possible societal sanctions against overweight people. In today’s environment, overweight people are told that their problem stems from a simple equation of “eating too much.” Yet, genetic variation in metabolism is so wide that no one can identify how much is too much. Congressional representatives and news media have even posed the possibility of “taxing” people who are too fat. Meanwhile, the average weight of Americans has been rising dramatically for the last two decades. This research promises to identify one of the causes of obesity, even if its cure is not in sight.