The study found that women who were prescribed 2.4 grams of long-chain Omega-3 supplements during the third trimester of pregnancy reduced their children's risk of asthma by 31 per cent. Long-chain Omega-3 fatty acids, which include eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in cold water fish, and key to regulating human immune response. The bottom line, as always, is that pregnant women should follow doctors' recommendations and not take any medication or supplement during pregnancy without explicit instruction from a health care provider. Childhood asthma is becoming more common and now affects 1 in 10 children. The women continued to take the supplements for one week after their delivery.
Kathleen Melanson, from the University of Rhode Island, who was not involved in the research, said it would be premature to widely recommend fish oil during pregnancy.
The new large-scale test, reported in The New England Journal of Medicine, is the first to see if supplements can actually lower the risk.
The children were regularly monitored for any signs of wheezing, asthma, lower respiratory tract infections and skin conditions until they were five. The health of the children was then tracked for five years, the age at which symptoms of asthma, such as wheezing, often first appear.
The effects were strongest among children whose mums had had low levels of omega-3 fatty acids before they started taking the fish oil supplements.
At the same time, our intake of omega-6 polyunsaturated fatty acids has increased, thanks to a higher use of vegetable oils in cooking, while the intake of omega-3 has dropped. This represents a 30 percent drop in asthma or wheezing cases among the participants' children.
The research team found that pregnant women with higher levels of EPA and DHA (the omega-3 fatty acids) in the blood were less likely to have a child with childhood asthma.
Both types of fatty acids have been dubbed "essential" fatty acids because they are mostly obtained from food and can not by produced by the human body.