Moderate intake of n-3 fatty acids is associated with stable erythrocyte resistance to oxidative stress in hypertriglyceridemic subjects

Background: The important triacylglycerol-lowering capacity of n-3 fatty ac ids is counterbalanced by their inherent sensitivity to oxidation. Inconsis tent results about the latter have been reported in hypertriglyceridemic in dividuals. After incorporation into cell membranes, n-3 fatty acids may alt er membrane-related functions. In view of the distinct composition of hyper triglyceridemic membranes and the prooxidant status in this condition, it c an be surmised that cell enrichment with the oxidizable n-3 fatty acids wil l be associated with an increased hemolytic process. Objective: We sought to evaluate the effect of fish oil consumption on n-3 fatty acid incorporation into erythrocyte membranes and subsequent ex vivo oxidative-stress-induced hemolysis in normotriglyceridemic and hypertriglyc eridemic subjects. Design: Sixteen normotriglyceridemic and 12 hypertriglyceridemic subjects w ere given 6 g fish oil/d for 8 wk. Blood samples were collected before and 4 and 8 wk after treatment. Resistance to 2,2'-azobis (2-amidinopropane) di lrydrochloride (AAPH)-induced hemolysis was assayed in fresh erythrocyte su spensions, and erythrocyte samples were stored at -70 degreesC for later an alysis of cholesterol, hemoglobin, fatty acids, vitamin E, and glutathione peroxidase activity. Results: Fish oil supplementation induced n-3 fatty acid incorporation in n ormotriglyceridemic and hypertriglyceridemic erythrocyte membranes without decreasing their resistance to AAPH. n-3 Fatty acids significantly protecte d normotriglyceridemic but not hypertriglyceridemic erythrocytes against he molysis. In normotriglyceridemic subjects only, the higher resistance to he molysis correlated with changes in cell vitamin E. Conclusion: Although they exhibit a high susceptibility to oxidation, n-3 f atty acids may preserve membrane integrity and represent an added benefit i n the treatment of hypertriglyceridemic patients.