[Effect of a diet supplemented with soybean oil or fish oil on the reversibility of docosahexaenoic acid deficiency (22:6w3) in the brain and erythrocytes of rats].
This study was undertaken, to evaluate the effects of dietary supplements containing either soybean oil (19:3w3; ALA), or fish oil (22:6w3; DHA), added to the lactating rat dam diet, on the levels of DHA in brain and erythrocytes of DHA deficient pups. Pregnant rats fed omega 3 deficient diets were divided at parturition into three groups. One group was kept on the same diet fed during pregnancy. The two remaining groups received the above mentioned omega 3 supplements. These feeding regimens were maintained during 18 days. Supplementation of diet with 114 mg DHA/100g diet, increased significantly the concentration of DHA in brain and erythrocytes of the suckling rats. In contrast, the effects of the supplementation with ALA (700 mg/100g diet), were limited to the increase of DHA content in the brain. This increase however, was partial, reaching only 50% of the normal. Results suggest that newborn rat has a limited capacity to convert DHA from ALA, becoming dependent of preformed DHA supply to cover DHA requirements at the cellular level.