You Might Be Able To Blame Your Father For Your Tendency To Gain Weight

Hereditary genes: we’ve all got them. From personality traits, to physical features, and even the susceptibility to catch certain diseases, everything that genetically makes up who we are as individuals was handed down from our parents.

However, researchers around the world have begun to question whether these traits are set in stone.

Can the environment that parents are exposed to alter the genes they pass down to their children?

In 2010, researchers at the University of Copenhagen fed male rats a high-fat diet and then mated them with female rats, finding that their offspring tended to gain more weight compared to the offspring of male rats who’d been fed a regular diet.

Building upon this experiment, Dr. Tracy L. Bale of the University of Pennsylvania took epigenetic molecules known as microRNAs from the sperm of male rats who had a high level of stress and injected them into embryos from mellow fathers. In the study findings, researchers learned that the developed embryos indeed resulted in rats with altered stress responses.

The studies above are based on theories surrounding the influence of epigenetics, the molecules that surround the DNA in sperm that can be affected by environmental factors. When environmentally stimulated, these genes in DNA are activated while others are silenced.

The overarching hypothesis is: “that a man’s experiences can alter his sperm, and that those changes in turn may alter his children.”

Scientists have only recently begun researching the potential effects of epigenetics in human fatherhood. In 2013 molecular epidemiologist, Adelheid Soubry, of KU Leuven University in Belgium began a study on the epigenetic differences in a group of 79 newborn children with either lean or obese fathers. Researchers identified epigenetic differences between children with obese fathers and those with lean ones, leading them to the conclusion that these differences had a high probability of being caused by that father’s own personal weight gain or loss.

Methylation, a process that places molecular caps on DNA, was found to differ in more than 9,000 genes in a study between 10 obese men and 13 lean men. The researchers also looked the methylation patterns of six obese men who had gotten bariatric surgery to lose weight and found more than 3,900 genes that were methylated differently a year after surgery.

Many scientists have reacted to the study with mixed feelings and skepticism. Epigenetics expert at the Albert Einstein College of Medicine, Dr. John M. Greally, says, “Honestly, I think a lot of what they have is noise.”

He goes on to explain that the number of men studied was much too small for the findings to be truly credible at this point, and also says that the genetic differences found between the men were likely to blame for the differences already seen in their sperm.

Greally does not completely deny the study’s validity, though. But he stresses the importance of larger, deeper research on the matter. “It’s doable,” he says. “It just requires that we’re bold about doing these things.”