LCPUFAs in pregnancy lower child’s asthma risk
Women in the third trimester of pregnancy who take supplements of n-3 long-chain polyunsaturated fatty acids (LCPUFAs) reduce their children’s risk of persistent wheeze or asthma as well as of lower respiratory tract infections, a study in Denmark demonstrated.
Investigators assigned 736 pregnant women at 24 weeks of gestation to receive 2.4 g per day of n-3 LCPUFA or placebo. They continued the supplementation until 1 week after delivery and followed the offspring for 3 years. The trial continued for an additional 2 years, during which the children had periodic clinical visits, to determine whether children with persistent wheeze had asthma. Participants also completed a food frequency questionnaire before the start of the trial and used daily diary cards after their children were born to record lung-related symptoms.
The risk of persistent wheeze or asthma was 23.7% in the control group compared with 16.9% in the treatment group, a reduction of about one-third. The supplementation’s preventive effect seemed strongest in the children of women who had low levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at the start of the trial and in those who carried the gene variant associated with low levels of EPA and DHA. Although supplementation was associated with reduced risk of infections of the lower respiratory tract, it did not appear to reduce the risk of eczema or allergic sensitization (Bisgaard H, et al. N Engl J Med. 2016:375:2530-2539).
This may turn out to be a path to reducing asthma worldwide. If further study confirms these findings, maternal supplementation could be targeted to mothers with low baseline levels of EPA and DHA and those with the gene variant that results in low levels. For every 5.5 mothers who are treated in these high risk groups, one child’s diagnosis of asthma could be prevented. Watch for more on this topic. —Michael G Burke, MD