A man’s age and lifestyle may have a significant effect on his children’s health

New research shows that a man’s age and lifestyle may have a significant effect on his children’s health — well before they are born.

It’s long been known that mothers may affect their child’s health through things like smoking or drinking alcohol, especially during pregnancy. But a growing body of research suggests that a man’s diet, drinking, smoking, and age may contribute to birth defects, autism, obesity, mental illnesses, and other problems in their kids.

The research suggests “that paternal age, lifestyle, and certain exposures can have an impact on children,” she says.Joanna Kitlinska, PhD, an assistant professor of biochemistry and molecular & cellular biology at Georgetown University, looked at dozens of studies on dads’ and children’s health.

Here’s how: Age and unhealthy habits cause changes to a man’s genes. Although scientists don’t yet fully understand how it happens, these changes are then passed on to his kids — perhaps even his grandchildren. For example, a man’s obesity may affect his genes in a way that makes his children more likely to be obese. Or tobacco smoke may damage a man’s sperm, allowing it to pass on potentially harmful genes to his children.

Most of the studies were able to show only a link between the two and didn’t prove one causes the other. Absolute risks of birth defects and other issues remain low for any one child, and researchers still believe Mom’s health while pregnant has a much stronger effect on their children’s health.

“These findings emphasize the fact that the interplay between nature and nurture — genetics and the environment — are far more complex than previously appreciated,” says Andrew Adesman, MD, chief of developmental and behavioral pediatrics at Cohen Children’s Medical Center of New York. Adesman was not involved in the review.

Here’s a breakdown of what Kitlinska and her colleagues found.


In one study that Kitlinska’s team reviewed, children whose fathers were over 40 had a much higher risk of autism compared to those with fathers under 30. Other large studies backed up this finding. Older fathers also tend to have children who are more likely to get schizophrenia.