New research suggests men who started smoking tobacco before the age of 11 have an elevated risk of having an overweight son.
"This discovery of transgenerational effects has big implications for research into the current rise in obesity and the evaluation of preventative measures," Marcus Pembrey, a professor of genetics at University College London, who led the study, said, Reuters reported.
Past studies have found transgenerational health impacts associated with smoking, there is little conclusive evidence. Researchers suggest the phenomenon could be related to epigenetics, which is when life factors turn certain genes on or off.
The recent study was inspired in part by a past Swedish study that found the abundance of food supply in paternal grandparents' childhood affected the survival rate of their grandchildren.
In this new study researchers looked at 9,886 fathers; fifty-four percent (5,376) of these men were smokers, three percent (166) of them admitted to smoking before the age of 11.
The sons of those who started smoking before the age of 11 were more likely to have a higher Body Mass Index (BMI) at the ages of 12, 15, and 17.
"These boys had markedly higher levels of fat mass - ranging from an extra five kilograms (kg) to 10kg between ages 13 and 17," the study said, Reuters reported. Ten kg is equivalent to about 22 pounds.
This finding was not significant in daughters.
"[The findings] may potentially provide new insights into factors that may influence development of obesity in childhood," Graham Burdge, an expert in human nutrition at the University of Southampton said, Reuters reported. "However, the findings only show associations and cannot be interpreted as indicating that paternal smoking at an early age causes obesity in their sons."
"The data are persuasive but not yet definitive as we need to confirm the same smoking related epigenetics changes in the kids' DNA," Tim Spector, a professor of genetic epidemiology at King's College London, said, Reuters reported.
