BELTSVILLE, MARYLAND. Fish oils are beneficial in the prevention of cancer and cardiovascular disease. They do, however, oxidize very easily and therefore add to the oxidant stress on the body. An experiment was recently carried out by the U.S. Department of Agriculture to see if an increased intake of vitamin E could counteract this detrimental effect of fish oils. Forty men aged 32 to 44 were involved. The men consumed a controlled diet for a total of 28 weeks. For the first 10 weeks they received placebo oil capsules (15 g/day), for the next 10 weeks they received fish oil capsules (15 g/day), and for the last 8 weeks they received the fish oil and vitamin E (200 mg) (all-rac-alpha-tocopherol). The urinary excretion of peroxidation products (malondialdehyde) more than doubled when the fish oil capsules were introduced but then dropped by a factor of four when vitamin E was added (taking fish oil and vitamin E together). The vitamin E concentration in the red blood cells dropped very significantly when fish oil was ingested but more than recovered with the vitamin E supplement. It is concluded that the negative effects of fish oil consumption can be overcome by taking the fish oil and vitamin E together.
Nair, Padmanabhan P., et al. Dietary fish oil-induced changes in the distribution of alpha-tocopherol, retinol, and beta-carotene in plasma, red blood cells, and platelets: modulation by vitamin E. American Journal of Clinical Nutrition, Vol. 58, July 1993, pp. 98-102