Grandma’s Smoking Habit Might Be Why You Have Asthma

You might get more passed down from your grandparents than just the color of their eyes or the shape of their nose.

The risk for hospitalization doubles for kids with asthma who are exposed to secondhand smoke, according to a study led by Mayo Clinic Children’s Research Center.

Rates of childhood asthma have increased rapidly in the last 50 years and experts suspect environmental exposures may be behind the trend. A few believe it’s due to an increased use of antibiotics and acetaminophen; others have found that obesity or vitamin D deficiency may play a role. The results indicated that when a grandmother smoked while pregnant-regardless of whether the mother did as well-a child’s risk of asthma increased from 10 to 22%.

A few animal studies have found that nicotine exposure is associated with epigenetic changes that can be passed down through the generations.

Researchers think this shows that people can inherit a risk for asthma from previous generations. “This may also be important in the transmission of other exposures and diseases”.

Whether or not the grandmothers smoked during pregnancy was recorded in the registry, as was any subsequent use of asthma medication by their grandchildren.

If past research is any indication, the notion of smokers passing down asthma from generation to generation isn’t surprising.

Changing environmental exposures have been thought to be responsible, but more recently, researchers have started looking to previous generations for clues, with increasing evidence that grandmothers are to blame. “This knowledge will help to clarify the findings concerning current risk factors in asthma research”, Lodge explained.

The study, presented at the European Respiratory Society’s global Congress 2015, is the first to investigate the risk in a whole population and use evidence about smoking habits taken directly from grandmothers at the time they were pregnant. Bertil Forsberg, presenting author of the study from Umeå University, Sweden, is to research the effect of grandmothers smoking while pregnant with boys who become fathers.

To understand more about the asthma epidemic, she added, researchers need to better understand how harmful exposures over a lifetime may influence disease risks in future generations.