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Could a Man's Life Experiences Affect the Genes He Passes On?

New research indicates a father's life experiences may actually change the genes he passes down to his children.

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You and your husband are tall. So chances are, your baby will be tall too. The idea that parents pass down certain genes and characteristics to their kids is commonly accepted knowledge. But what if a father's life experiences also have the power to shape a child? That's a hypothesis that was tested in a recent study.

Researchers found a father's sperm can actually be altered by his life experiences. The idea to test this theory started when a University of Copenhagen doctor fed male rats a diet high in fat. Those rats fathered offspring that tended to gain more weight and had higher insulin levels when compared with male rats fed a regular diet. Likewise, male rats exposed to stressful situations were more likely to father offspring with a heightened response to stress.

The so-called field of epigenetics of fatherhood—the idea that life experiences can actually alter sperm, and therefore the genes fathers pass down to offspring—is a new field, but human sperm has been tested to see if the same phenomenon exists. Danish researchers looked at 10 obese men and 13 lean ones. Six of the fathers involved in the study were undergoing bariatric surgery. It was noted thousands of genes actually changed after the procedures, including one responsible for appetite control.

Researchers have not yet been able to determine definitively if these changes affect the children of the men. "I don't want to speculate whether it's positive or negative in the following generation," said Dr. Romain Barres. "We're going to try to see if there's something transmitted all the way down." And that is the next step; to see if the altered genes are passed to offspring.

It's an amazing idea, and also kind of scary; as parents, we already feel a tremendous amount of responsibility in raising our kids. But what if a dad's diet, and his exposure to stress—some of which is outside his control—can actually impact his future kids for the rest of their lives? That's enough to stress anyone out!

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.