Grandmother's smoking may increase asthma risk in grandchildren: study

Melbourne: Children with grandmothers who smoked during pregnancy may have an increased risk of asthma even if their mothers did not smoke, according to a new study.

Researchers studied whether smoking in grandmothers, while they were pregnant with daughters, was linked with an increased risk of asthma in their grandchildren.

Data was taken from the Swedish Registry and included 44,853 grandmothers from 1982 to 1986.

Smoking exposure was recorded during pregnancy and use of asthma medication was recorded in 66,271 grandchildren.

The results found that if grandmothers had smoked during their pregnancy, there was an increased risk of asthma in grandchildren, even if their mothers had not smoked during pregnancy. The risk of asthma was increased by 10 to 22 per cent.

"We found that smoking in previous generations can influence the risk of asthma in subsequent generations. This may also be important in the transmission of other exposures and diseases," said Caroline Lodge, research fellow at the University of Melbourne in Australia.

"For us to understand more about the asthma epidemic, we require a greater understanding of how harmful exposures over your lifetime may influence the disease risks of generations to come," Ms Lodge said.

"Additionally, researchers in this area need to be aware, when interpreting the asthma risk from current exposures and genetic predisposition, that individuals may carry an inherited, non-genetic, risk from exposures in previous generation. This knowledge will help to clarify the findings concerning current risk factors in asthma research," she said.

The study was presented at the European Respiratory Society's International Congress 2015 in the Netherlands.