The effect of dietary supplementation with n-3 polyunsaturated fatty acids on the synthesis of interleukin-1 and tumor necrosis factor by mononuclear cells.
We examined whether the synthesis of interleukin-1 or tumor necrosis factor, two cytokines with potent inflammatory activities, is influenced by dietary supplementation with n-3 fatty acids. Nine healthy volunteers added 18 g of fish-oil concentrate per day to their normal Western diet for six weeks. We used a radioimmunoassay to measure interleukin-1 (IL-1 beta and IL-1 alpha) and tumor necrosis factor produced in vitro by stimulated peripheral-blood mononuclear cells. With endotoxin as a stimulus, the synthesis of IL-1 beta was suppressed from 7.4 +/- 0.9 ng per milliliter at base line to 4.2 +/- 0.5 ng per milliliter after six weeks of supplementation (43 percent decrease; P = 0.048). Ten weeks after the end of n-3 supplementation, we observed a further decrease to 2.9 +/- 0.5 ng per milliliter (61 percent decrease; P = 0.005). The production of IL-1 alpha and tumor necrosis factor responded in a similar manner. Twenty weeks after the end of supplementation, the production of IL-1 beta, IL-1 alpha, and tumor necrosis factor had returned to the presupplement level. The decreased production of interleukin-1 and tumor necrosis factor was accompanied by a decreased ratio of arachidonic acid to eicosapentaenoic acid in the membrane phospholipids of mononuclear cells. We conclude that the synthesis of IL-1 beta, IL-1 alpha, and tumor necrosis factor can be suppressed by dietary supplementation with long-chain n-3 fatty acids. The reported antiinflammatory effect of these n-3 fatty acids may be mediated in part by their inhibitory effect on the production of interleukin-1 and tumor necrosis factor.
Department of Medicine, New England Medical Center Hospital, Boston, MA.
S
S
Endres
R
R
Ghorbani
V E
VE
Kelley
K
K
Georgilis
G
G
Lonnemann
J W
JW
van der Meer
J G
JG
Cannon
T S
TS
Rogers
M S
MS
Klempner
P C
PC
Weber
D000328:Adult; D002634:Chemotaxis, Leukocyte / Q000187:drug effects; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D015232:Dinoprostone / Q000097:blood; D005395:Fish Oils / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D009504:Neutrophils / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
D004042:Dietary Fats, Unsaturated; D005395:Fish Oils; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D015232:Dinoprostone