Pro‐ and anti‐inflammatory cytokines in healthy volunteers fed various doses of fish oil for 1 year

Abstract

Abstract. Dietary supplementation with n-3 fatty acids from fish oil alleviates inflammation in various chronic inflammatory disease states. Reductions in the production of pro-inflammatory cytokines interleukin 1b (IL1b), tumour necrosis factor alpha (TNF-a), and interleukin 6 (IL-6) have been seen in humans after short-term n-3 fatty acid supplementation. We investigated longterm effects of dietary n-3 fatty acids on circulating cytokine concentrations and on ex vivo stimulated whole-blood production of IL-1b, TNF-a and interleukin 1 receptor antagonist (IL-1Ra), the naturally occurring antagonist of IL-1. A total of 58 monks with a mean age of 56 years were randomized into four groups and their diets were supplemented with 0, 3, 6, or 9 g of fish oil, providing 0, 1·06, 2·13 or 3·19 g of n-3 fatty acids per day. Subjects received equal amounts of saturated fatty acids, vitamin E and cholesterol. Compliance was excellent and erythrocyte fatty acid profiles closely reflected the amounts of n-3 fatty acids ingested. In the group receiving 9 g of fish oil per day, no influence of n-3 fatty acids on circulating cytokine concentrations was observed relative to placebo. Endotoxin-stimulated whole-blood cytokine production was measured at 26 and 52 weeks after the start and at 4, 8 and 26 weeks after cessation of supplementation. In all groups, the production of IL-1b and IL-1Ra was higher during supplementation than afterwards. However, no differences in cytokine production were noted between the placebo group and the various treatment groups at any point in time. Our results suggest that long-term supplementation of fish oil does not affect ex vivo cytokine production in man.

Effects of fish oil on the neuro-endocrine responses to an endotoxin challenge in healthy volunteers

“…ln monks submitted to an endotoxin challenge after a prolonged FO supplementation (26-52 weeks supplementation) similar cytokine results were reported. 38 Altogether, these results suggest that FO does not exert a major effect on the inflammatory response to LPS, a very short-lived inflammation.…”

Intake of n-3 fatty acids from fish does not lower serum concentrations of C-reactive protein in healthy subjects

“…In healthy volunteers, increasing fish oil intake suppressed the in vitro synthesis of interleukin-2, interleukin1b, interleukin-1a, and tumor necrosis factor-a (Endres et al, 1989(Endres et al, , 1993. However, placebo-controlled studies found that fish oil does not affect ex vivo cytokine production (Blok et al, 1997) or the functional activity of neutrophils, monocytes, or lymphocytes in healthy humans (Kew et al, 2003). Few studies investigated effects of n-3 fatty acids on CRP.…”

The Effect of Supplementation With Omega-3 Fatty Acids on Soluble Markers of Endothelial Function in Patients With Coronary Heart Disease

“…31 On the other hand, Blok et al 32 reported in a prospective trial that fish oil supplementation did not affect the concentrations of circulating cytokines. Furthermore, they found the ex vivo production of cytokines (interleukin-I␤, tumor necro- P1, group differences at baseline; P2, group differences after 4 weeks' treatment; PD, group differences in relative changes from baseline.…”