December 29, 2016 — Studies of fish oil and health are like studies about coffee — there’s plenty of contradictory information out there.
With that in mind, here’s the latest turn: A Danish study finds that women who took fish oil supplements during pregnancy reduced the risk of asthma in their children.
“I would say that the finding that the effect was there was maybe not the surprise, because there have been indications,” says the study’s lead researcher, Dr. Hans Bisgaard, of the University of Copenhagen. “But the magnitude was very surprising to us.”
Bisgaard is a pediatrician and runs a privately funded research enterprise called the Copenhagen Prospective Studies on Asthma in Childhood. He is not the first person to study whether fish oil supplements during pregnancy can affect asthma, but his study was large and carefully designed.
Researchers gave 2.4 grams of either fish oil capsules or olive oil capsules to more than 700 pregnant women during the third trimester of pregnancy. (Nobody knew which capsules contained the fish oil.)
They then monitored the health of the children for at least five years. And it turns out that 17 percent of the children in the fish oil group had developed persistent wheezing or asthma by the age of 5, compared with 24 percent of children in the group that got olive oil. That’s about a 30 percent reduction in cases of asthma or wheezing. (Because the Danish study included “persistent wheezing,” it’s not possible to compare these rates with asthma rates in the U.S.)
Bisgaard and his colleagues report their findings in Thursday’s New England Journal of Medicine. He says by far the biggest benefit seemed to be among babies born to women who initially had low blood levels of the lipids found in fish oil.