The effect on human tumor necrosis factor alpha and interleukin 1-beta production of diets enriched in n-3 fatty acids from vegetable oil or fish oil.
The effect on human tumor necrosis factor alpha and interleukin 1-beta production of diets enriched in n-3 fatty acids from vegetable oil or fish oil.
Year: 1996
Authors: G E Caughey, E Mantzioris, R A Gibson, L G Cleland, M J James.
Publication Name: Amer. J. Clin. Nutr.
Publication Details: Volume 63; Number 1; 116.
Abstract:
The cytokines tumor necrosis factor (TNF a) and interleukin 1? (IL??) are involved as mediators in inflammatory conditions such as synovial hyperplasia, leukocyte infiltration and cartilage degradation present in such diseases as rheumatoid arthritis. Both cytokines are also present in atherosclerotic lesions. This research assessed the effectiveness of n?3 PUFA from either flaxseed oil (rich in ALA) or fish oil (rich in EPA and DHA) for inhibition of mononuclear cell TNF a and IL?? production. Twenty?eight healthy male subjects consumed their normal diet supplemented with 14 g/day of ALA from flaxseed oil or a control diet containing sunflower oil for 4 weeks. Following the four week period, both groups were switched to 9 g/day of fish oil supplementation for a further four weeks. In the flaxseed oil group, cellular ALA and EPA increased 3.0 and 2.3 fold, respectively. TNF a, IL??, thromboxane B2 and prostaglandin E2 production decreased by 30%, 31%, 29% and 30%, respectively following the flaxseed oil diet. Fish oil supplementation for a further four weeks resulted in an inhibition of both cytokine and eicosanoid production. In the flaxseed oil and sunflower groups that had been switched to fish oil, TNF a was inhibited by 77% and 70%, respectively; IL?? was inhibited by 81% and 78%, respectively; thromboxane B2 was inhibited by 48% and 52%, respectively; and prostaglandin E2 was inhibited by 28% and 55%, respectively, by eight weeks. There was a significant inverse relationship between TNF a and IL?? synthesis and mononuclear cell content of EPA. The production of these cytokines decreased as cellular EPA increased to 1% of total fatty acids. The results indicated that flaxseed oil rich in ALA inhibits the synthesis of TNF a and IL?? as well as the production of the potent pro?inflammatory eicosanoids, thromboxane B2 and prostaglandin E2. The authors postulated that the mechanism for inhibition of TNF a and IL?? may involve a reduction in thromboxane B2 synthesis. Diets high in fish oil are associated with reductions in atherosclerosis and rheumatoid arthritis through effects on eicosanoid metabolism. However, fish oil consumption is generally low in the Western diet and thus, flaxseed oil appears to be an alternative means to increase n?3 fatty acid consumption in the general population. The authors concluded that FO with its elevated ratio of ALA to LA can be an effective component in anti?atherosclerotic and anti?inflammatory diets.
