Women who took fish oil during the final three months of pregnancy lowered their children’s risk of developing asthma by about one third, according to a new study from Denmark.
Among children whose mothers took fish oil capsules, 16.9 percent had asthma by age 3, compared with 23.7 percent whose mothers were given placebos. The difference, nearly 7 percentage points, translates to a risk reduction of about 31 percent. The results of the study, which included 736 women, were published in the New England Journal of Medicine. Half the women took 2.4 grams of fish oil daily and half took placebo capsules of olive oil through one week after they delivered their babies.
Before doctors can make any recommendations, the study should be replicated, and fish oil should be tested earlier in pregnancy and at different doses, Hans Bisgaard, MD, the leading author of the study, told the New York Times. He is a professor of pediatrics at the University of Copenhagen and the head of research at the Copenhagen Prospective Studies on Asthma in Childhood, an independent research unit. He said it wasn’t possible to tell from the study whether pregnant women could benefit from eating more fish, rather than taking the supplements. The 2.4 grams per daily of fish oil is about 15 to 20 times what most Americans consume from food.
Bisgaard said that, pending further study, the best way to apply the findings would probably be to test women for the fatty-acid levels in their blood, and for the genetic variant, to determine who might benefit from fish oil. He said that genetics could differ among different populations and that there might be ethnic variations in risk.
Previous research has suggested that fish oil might help prevent asthma, and help reduce the symptoms of asthma, based on omega-3’s power to fight inflammation.