Perinatal omega-3 in childhood allergy and inflammation

It has been hypothesized that a maternal diet rich in omega-3 polyunsaturated fatty acids (ω-3 PUFAs) can attenuate neonatal immune development, and alter their allergic responses later in life. Allergies include eczema, asthma and food allergies. This may be due to the ability of these ω-3 PUFAs to inhibit metabolism of arachidonic acid (AA) and thus reduce the formation of inflammatory mediators such as prostaglandins and leukotrienes. They are commonly produced in response to an exogenous stimulus and are important in the allergic response.
This review aimed to study if supplementation of pregnant women with ω-3 PUFAs during pregnancy and lactation decreased the risk of allergy and inflammation in the offspring. It included 5 randomized controlled trials that totaled 949 participants. These studies reported on the clinical or immunological outcomes of the offspring- eg asthma, atopy or response to the egg skin prick test (SPT). The latter performed only in the first 12 months of life.
For food allergy, 3 randomized controlled trials (RCTs) were found and two showed no significant differences in the children born to ω-3 PUFA supplemented mothers versus those whose mothers were not supplemented. One RCT did show a statistically significant difference (P<0.037) favouring ω-3 PUFA, but the other two trials had P values >0.05.  Thus although one study demonstrated that the omega-3 group had a significantly lower rate of food allergies than the control group, the result was insignificant when combined with the other 2 studies.
Another parameter studied was the response to the egg skin prick test, which tests for the presence of egg-specific IgE antibodies. However, a positive response does not mean that food allergy is present since it can be observed in tolerant individuals. For positive response to the egg SPT, supplementation reduced the positive response significant (OR 0.332). However this was only done in two RCTs, including 187 participants.
3 studies reported on atopy (eczema or atopic dermatitis). There was no significant difference in atopic dermatitis between the two groups.
For asthma, 2 RCTs were included and ω-3 PUFA supplementation in pregnancy found to significantly reduce childhood asthma. A study where supplementation only began in lactation failed to show any significant differences in the rates of asthma, possibly attributed to development of the fetal immune system during gestation.  Two studies also reported decreased IL-13 production in cord blood of those born to mothers who received the supplement. IL-13 is associated with allergic diseases due to its ability in inducing IgE synthesis from B cells and inducing Th2 differentiation of T helper cells.
In summary, ω-3 PUFA supplementation during pregnancy decreased childhood asthma and infant response to egg skin prick test.

Fish oil-Natural (Tuna) is present in PM Procare (Pregnancy & Pregnancy formulation) and PM Bright Kids (for children’s eye, neural and immune health).

Reference
Klemens, C.M., D.R. Berman, and E.L. Mozurkewich, The effect of perinatal omega-3 fatty acid supplementation on inflammatory markers and allergic diseases: a systematic review. BJOG, 2011. 118(8): p. 916-25.