Supplementation with high-dose DHA omega-3 oil whilst pregnant may help to enhance infants' immune systems, according to new research.
The study, published online in the journal Pediatrics, reports that mothers taking 400 milligrams of a supplement containing docosahexaenoic acid (DHA) had babies which overcame colds faster than babies with mothers not taking DHA.
"DHA supplementation during pregnancy decreased the occurrence of colds in children at 1 month and influenced illness symptom duration at 1, 3, and 6 months," said the authors, led by Usha Ramakrishnan an associate professor of global health at Emory University, USA.
"If women want to take it, it's unlikely to cause harm in the overall picture of the babies we looked at," said Ramakrishnan
"The magnitude of the benefit seems to be variable and depends on the outcome you looked at. It may not be a benefit for everybody."
Infants in the study were examined at 1, 3 and 6 months old, and their mothers were asked whether, in the past two weeks, the infants had symptoms such as congestion, phlegm, vomiting and rashes and how long those lasted.
While both groups had similar numbers of illnesses, infants whose mothers had taken DHA saw many illness symptoms reduced.
"At one month, the DHA group experienced 26%, 15%, and 30% shorter duration of cough, phlegm, and wheezing, respectively, but 22% longer duration of rash," said the researchers.
At three months, Ramakrishnan and her team reported that infants in the DHA group spent 14 per cent less time ill.
"At six months, infants in the DHA group experienced 20%, 13%, 54%, 23%, and 25% shorter duration of fever, nasal secretion, difficulty breathing, rash, and "other illness," respectively, but 74% longer duration of vomiting," they said.
While this shows that the duration of cold symptoms were shorter in children taking DHA, the researchers noted the worrying finding that those also children had rashes and bouts of vomiting last longer.
"We don't know what to make of it, and when you're looking at a whole bunch of things, some are significant and some aren't," said Ramakrishnan, who added that the researcher team are continuing to investigate the long-term effects of DHA.
The ongoing investigation in Mexico will also allow the team to examine some of the less encouraging findings of the study, but will also mean they can assess other effects as the children grown.
"[We are] interested in the long-term implications, if these children grow better and are smarter," concluded Ramakrishnan, noting the children are turning 4 now, and researchers will study their school performance at age 5, among other outcomes.