Could an Obese Dad’s Sperm Pass Traits to Kids?
By Amy Norton
Researchers found that sperm from normal weight and obese men differed in how some genes were turned “on” or “off.” And the differences were seen in gene regions linked to brain development and appetite control.
The Danish scientists said the findings may offer one biological explanation for why heavy dads often have heavy kids.
“At a basic level, most people know that overweight parents often have overweight kids,” said Anthony Comuzzie, a spokesman for the Obesity Society and a researcher at the Texas Biomedical Research Institute, in San Antonio.
“That’s not all genetics, of course, but a good part of it is,” said Comuzzie, who was not involved in the new study.
However, he added, it may be more complicated than the set of genes you inherit. The current study tackled “epigenetics” — chemical mechanisms that determine whether a gene is active or dormant at certain times.
Research has shown that epigenetic patterns can be altered through behavior, including diet and exercise. And like genes, epigenetic patterns can be inherited.
Scientists are just beginning to understand how it works, but research in insects and rodents shows that parents’ epigenetic “marks” can affect the health of their offspring.
It all suggests that we inherit more than a “random mix of genes from our ancestors,” said lead researcher Romain Barres, an associate professor at the University of Copenhagen, in Denmark.
Instead, he said, people may also receive “a biological imprint of their [parent’s] behavior and lifestyle.”
For the study, published online Dec. 3 in the journal Cell Metabolism, Barres and colleagues analyzed sperm from 10 men who were obese and 13 men with a normal weight. The investigators found that the two groups showed different DNA methylation patterns in their sperm — including in gene regions linked to appetite control.
Comuzzie explained it this way: “You can have two genes that are structurally identical. But they will not function the same way if they have different DNA methylation patterns.”