Consuming certain kinds of omega-3 fatty acid derived from fish oil during pregnancy could cut down the risk of childhood asthma by almost a third, a research publication has shown.

The study, published in the New England Journal of Medicine last month, found that women who were prescribed 2.4 grams of the omega-3 fatty acid supplements during the third trimester of their pregnancy reduced their child’s risk of asthma by 31%, a press release issued by the researchers in Denmark and Canada said.

The supplement also reduced the risk of lower respiratory tract infections in children.

People who follow carbohydrate- and red meat-heavy Western diets have lower intakes of omega 3, which in turn possibly increase the risk of childhood asthma, the researchers suspected.

The research found that women with low levels of omega-3 fatty acids at the beginning of the study benefited the most from the supplements. The press release the relative risk of developing asthma in children of these women was reduced by 54%.

The proportion of women with low levels of these fatty acids in their blood is higher in Canada and the US than in Denmark, said Professor Ken Stark, Canada Research Chair in Nutritional Lipidomics and professor in the Faculty of Applied Health Sciences at Waterloo, who led the testing of pregnant women’s blood samples.

Blood samples of 695 Danish women were tested at around six months of pregnancy and then a week after delivery. The researchers monitored the health of each of the participants’ children for five years, which is the age asthma symptoms can be clinically established.

The researchers included Hans Bisgaard, Jakob Stokholm, L Chawes, Nadja H Vissing, Elin Bjarnadóttir and Ann-Marie M Schoos, among others.