New study links grandparents’ smoking to your body fat

Women whose grandfathers or great-grandfathers started smoking cigarettes at a young age are likely to have more body fat, new research suggests.

In the 30th year of the Children of the 90s study in England, researchers have linked higher body fat in females to paternal grandfathers or great-grandfathers who began smoking before the age of 13, according to a report published in the journal Scientific Reports.

It’s potentially one of the first pieces of evidence that human exposure to substances can be passed on to descendants, though researchers have said much more work is needed to understand how that may happen.

Experiments using animals have already found that exposing males to certain chemicals prior to breeding can affect their offspring, but, up until now, researchers have doubted whether this phenomenon is present in humans.

“If these associations are confirmed in other datasets, this will be one of the first human studies with data suitable to start to look at these associations and to begin to unpick the origin of potentially important cross-generation relationships,” Jean Golding, the founder of the Children of the 90s study and the report’s lead author, said in a news release. “There is much more to explore.”

The Children of the 90s study, also known as the Avon Longitudinal Study of Parents and Children, has been studying a cohort of more than 14,000 individuals born in 1991 and 1992, along with their parents, for 30 years.

Now, as the children of the original cohort begin to have children of their own, scientists are able to gather information on all three generations, allowing them to research some social and health issues for the first time.

“This research provides us with two important results,” Golding said of the study’s latest finding.

“First, that before puberty, exposure of a boy to particular substances might have an effect on generations that follow him. Second, one of the reasons why children become overweight may be not so much to do with their current diet and exercise, rather than the lifestyle of their ancestors or the persistence of associated factors over the years.”