The occurrence of eczema and food allergies was 16 and 13 per cent lower, respectively, in infants of mothers receiving the fish oil supplements during pregnancy and the early months of breast-feeding, compared to placebo, according to findings published in the journal Acta Paediatrica.
“This randomized placebo-controlled double-blind study shows that omega-3 supplementation during pregnancy and lactation may reduce the risk of developing allergic sensitization to egg, IgE-associated eczema and food allergy during the first year of life,” wrote the authors, led by Catrin Furuhjelm from Linkoping University.
Immunoglobulin E (IgE) is the predominant antibody associated with an allergic response.
The new study adds to the ever-growing list of studies supporting the potential health benefits of omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA. Much of its healthy reputation that is seeping into consumer consciousness is based largely on evidence that it can aid cognitive function and may help protect the heart against cardiovascular disease.
From mother to child
Furuhjelm and her co-workers recruited 145 pregnant women with allergies, or with partners or other children with allergies. Starting at the 25th week of their pregnancy, and continuing for between three and four months of breastfeeding, the women were randomly assigned to receive either daily fish oil supplements providing 1.6 g of EPA and 1.1 g of DHA (Bio Marin capsules from Pharma Nord, Denmark), or placebo.
Using a range of tests, including clinical examination, skin prick tests, and blood tests for IgE, the researchers observed a 2 per cent prevalence of food allergy in the omega-3 group, compared to 15 per cent in the placebo group.
Furthermore, the incidence of IgE-associated eczema was only 8 per cent in the omega-3 group, compared to 24 per cent in the placebo group.
“Our findings suggest that the mechanisms leading to sustained IgE antibody production early in life may be inhibited by the omega-3 fatty acids EPA and DHA,” wrote Furuhjelm.
Commenting on the mechanism, the Linkoping-based scientists proposed several possibilities. Both DHA and EPA may produce changes in the fluidity of the membranes of immune cells, and reduce the levels of the omega-6 fatty acid arachidonic acid (AA). By inhibiting the metabolism of AA, the formation of the less inflammatory eicosanoids is favoured, which may be linked to lower allergic sensitization in the children, said the researchers.
“Additional anti-inflammatory effects of EPA andDHA in early immune development through bioactive lipids, lipoxins, neuroprotectines and resolvins, have been discussed but it is not clear whether those are plausible explanatory mechanisms regarding our findings,” they said.
Food allergy rises
The number of allergic disease has also been rising, with an estimated eight per cent of children in the EU suffering from food allergies, according to the European Federation of Allergy and Airways Diseases Patients' Associations.
The most common food allergen ingredients and their derivatives are cereals containing gluten, fish, crustaceans, egg, peanut, soybeans, milk and dairy products including lactose, nuts, celery, mustard, sesame seed, and sulphites.
Source: Acta Paediatrica
Published online ahead of print, doi: 10.1111/j.1651-2227.2009.01355.x
“Fish oil supplementation in pregnancy and lactation may decrease the risk of infant allergy”
Authors: C. Furuhjelm, K. Warstedt, J. Larsson, M. Fredriksson, M. Fageras Bottcher, K. Falth-Magnusson, K. Duchen