Dietary Fish-Oil Supplementation Alters Leukocyte Funciton and Cytokine Production in Healthy Women

The effect of low-dose fish oil supplementation on cytokines and white cell function in women was investigated. Thirty-three healthy, nonsmoking women entered the double-blind study. For 4 weeks, 2.4 g of either fish oil (n=16) or fish oil with vitamin E (n=17) was added daily to the subjects' otherwise unchanged diets. Venous blood samples were taken at the onset of the trial, after the supplementation period, and again after a 9-week washout period. Plasma levels of platelet-derived growth factor and myeloperoxidase were measured using immunoassays. The intracellular peroxidase content of white blood cells was measured using a staining technique. Platelet-derived growth factor levels were significantly lowered after supplementation (P less than or equal to.05). Intracellular peroxidase was increased (P less than or equal to.01), and extracellular myeloperoxidase levels were lowered (P less than or equal to.05). Taken together, these results suggest that the anti-inflammatory effect of fish oil may be due at least partly to alterations in white cell function and growth factor levels.