Waterloo, Belgium—Expectant mothers who take specific omega-3 fatty–acid supplements can significantly reduce their offspring’s risk of childhood asthma.
The study, published in the New England Journal of Medicine, reports that women reduced their unborn child’s risk of asthma by 31% when, during the third trimester of pregnancy, they were prescribed 2.4 grams of long-chain omega-3 supplements, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Both substances are found in cold-water fish and considered important in regulating human immune response.
“We’ve long suspected there was a link between the anti-inflammatory properties of long-chain omega-3 fats, the low intakes of omega-3 in Western diets and the rising rates of childhood asthma,” said Professor Hans Bisgaard of COPSAC at the Copenhagen University Hospital in Denmark. “This study proves that they are definitively and significantly related.”
For the study, researchers employed rapid analytical techniques developed by and performed at the University of Waterloo to measure levels of EPA and DHA in the expectant mothers’ blood. The greatest benefit of the supplements, according to the testing, was in women with low blood levels of EPA and DHA at the beginning of the study, reducing their children’s relative risk of developing asthma by 54%.
“The proportion of women with low EPA and DHA in their blood is even higher in Canada and the United States as compared with Denmark. So we would expect an even greater reduction in risk among North American populations,” said Ken Stark, PhD, Canada Research Chair in Nutritional Lipidomics and professor in the Faculty of Applied Health Sciences at Waterloo, who led the testing. “Identifying these women and providing them with supplements should be considered a front-line defense to reduce and prevent childhood asthma.”
For the study, researchers analyzed blood samples of 695 Danish women at 24 weeks’ gestation and 1 week after delivery. They then monitored the health status of each participating child for 5 years, which is the age asthma symptoms can be clinically established.
With 695 children participating, the risk of persistent wheeze or asthma in the treatment group was 16.9% versus 23.7% in the control group, corresponding to a relative reduction of 30.7%. Analyses of secondary end points showed that supplementation with n-3 long-chain polyunsaturated fatty acids (LCPUFA) was associated with a reduced risk of infections of the lower respiratory tract—31.7% versus 39.1%—but there was no statistically significant association between supplementation and asthma exacerbations, eczema, or allergic sensitization.
“Supplementation with n?3 LCPUFA in the third trimester of pregnancy reduced the absolute risk of persistent wheeze or asthma and infections of the lower respiratory tract in offspring by approximately 7 percentage points, or one third,” study authors conclude.
“Asthma and wheezing disorders have more than doubled in Western countries in recent decades,” Bisgaard added. “We now have a preventative measure to help bring those numbers down.”
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