In addition to making babies smarter, expectant moms who consume a diet based on fish and walnut oils may also be kickstarting their babies' immune systems and warding off future allergies, scientists say.
The French study, published in this months's Journal of Physiology, claims to have found that a group of polyunsaturated fatty acids -- also known as n-3PUFAs -- helps the baby develop a more 'permeable' gut.
A more permeable gut, in turn, enables bacteria and new substances to pass through the lining and into the bloodstream, which then triggers the immune system and the production of antibodies.
"The end result is that the baby's immune system may develop and mature faster -- leading to better immune function and less likelihood of suffering allergies," said lead researcher Gaelle Boudry in a statement.
While other clinical studies have also been able to demonstrate the same relationship, scientists at the INRA research institute in Rennes, France claim theirs is the first to explain how it all works. Their study was conducted on piglet intestines.
The fatty acids studied can be found in foods like fish, walnut oil and flaxseed -- foods that are all but marginal in the western diet and which are being increasingly replaced by corn oils and other types of fatty acids, Boudry said.
Meanwhile, though obstetricians routinely encourage pregnant women to consume fish oil supplements in the belief it helps with a baby's cognitive development, the theory remains an inconclusive one.
In 2003, a Norwegian study showed that babies born to women who consumed cod liver oil during pregnancy had higher IQ levels at the age of four. No cognitive benefit however, was observed in infants or seven-year-olds.
A subsequent study published last year in the Journal of the American Medical Association tested those theories and found little difference in babies whose mothers consumed vegetable oil capsules compared with those who took fish oil supplements.
For more info on the health benefits of fish oil, visit the US National Institutes of Health at http://www.nlm.nih.gov/medlineplus/druginfo/natural/993.html.