Omega 3 pregnancy: fish oil helps children's immune system

During the third trimester of gestation, mothers-to-be should eat at least 2 servings of salmon, a fatty fish rich in Omega 3, every week to improve the activity of the babies' immune system. The suggestion comes from the pages of the American Journal of Clinical Nutrition, which published findings by a group of scientists led by Paul Noakes, a researcher at the University of Southampton (UK). The research adds new details to the usefulness of taking foods rich in Omega-3 to boost immunity. Indeed, other studies have shown that the use of fish oil-based Omega-3 supplements has a beneficial effect on the immune system.

Omega-3 in gestation: from mothers to babies

The study by Noakes and colleagues involved 123 pregnant women who were randomly assigned to one of 2 possible groups. Mothers-to-be in the first group were instructed to continue with their usual diet, which was low in fatty fish. The other women were asked to eat 2 servings of salmon per week, corresponding to 3.45 total grams of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the main Omega-3s in which saltwater fish are rich. The researchers collected blood samples from the umbilical cord from the 20th week of gestation until the end of pregnancy to measure Omega-3 and IgE (antibodies associated with allergic reactions) levels and immune response. The health status of the children, on the other hand, was assessed at the age of 6 months. It emerged that the introduction of salmon into the diet is associated with reduced production of certain molecules involved in the immune response triggered by the presence of allergens. Included among these molecules are certain interleukins (ILs). In particular, researchers observed a reduction in IL-2, IL-4, IL-5 and IL-10. Salmon consumption was found to be associated with less activation of the immune system by allergens even in cases where one of the parents has allergies. No difference was found in either IgE levels or in the incidence or frequency of eczema between the children of women in the two different study groups.

A question of doses and interactions

According to experts, the lack of efficacy in terms of protection from IgE production at 6 months of age could be due to the intake of too low doses of Omega-3 or to the fact that EPA and DHA should be introduced into the diet from earlier stages of gestation. In fact, 2 servings of salmon per week corresponds to the intake of the minimum amounts of Omega-3 that an adult needs to ensure proper intake of these valuable nutrients. These doses of EPA and DHA may not be sufficient to influence immune system activity in those with a family history of allergies. Furthermore, the authors of the research pointed out that in addition to Omega-3s, salmon also contains other important molecules, such as vitamin D and selenium, which are able to influence immune system activity. Therefore, the researchers do not rule out that the benefits of introducing this fish into the diet are associated with the combined action of Omega-3 with these other nutrients.    

Source 

1. Noakes PS, Vlachava M, Kremmyda LS, Diaper ND, Miles EA, Erlewyn-Lajeunesse M, Williams AP, Godfrey KM, Calder PC, "Increased intake of oily fish in pregnancy: effects on neonatal immune responses and on clinical outcomes in infants at 6 mo," Am J Clin Nutr. 2012 Feb;95(2):395-404. Epub 2012 Jan 4