THE ABSORPTION AND EFFECT OF DIETARY SUPPLEMENTATION WITH OMEGA-3-FATTY-ACIDS ON SERUM LEUKOTRIENE B-4 IN PATIENTS WITH CYSTIC-FIBROSIS

The substitution of omega-3 (n-3) fatty acids for omega-6 (n-6) fatty acids generates eicosanoids with diminished inflammatory effects. As t he lungs of patients with cystic fibrosis (CF) are in a state of chron ic inflammation in which increased amounts of eicosanoids are found, n -3 supplementation may reduce this level of inflammation and result in clinical improvement. The absorption and clinicals effects of n-3 vs. n-6 fatty acids in CF were measured in a prospective, randomized, dou ble-blind, crossover study in which 14 patients with CF (age: 6-16 yea rs, mean 10.5 years; baseline Shwachman-Brasfield scores: 41-88, mean 76.7) received 6 weeks of n-3 ethyl ester concentrate from menhaden oi l (100-131 mg/kg/day, mean 112.8) or n-6 fatty acids from safflower oi l (102-132 mg/kg/day, mean 113.3), followed by a washout period of 6 w eeks, and then 6 weeks of the other supplement. Analysis by gas chroma tography showed that n-3 supplementation resulted in increased eicosap entaenoic acid (20:5n-3) in platelet phospholipids, from 0.14 to 2.16% , P < 0.05 and in increased docosahexaenoic acid (22:6n-3), from 1.33 to 3.72%, P < 0.05. Clinical effects were evaluated at weeks 0, 6, 12, and 18, and analyzed for differences among the n-3, n-6, and washout periods. No adverse effects were reported or observed. No statisticall y significant differences were found (ANOVA, P > 0.05) in Shwachman-Br asfield scores, sweat test, weight change, or forced expiratory volume and flow (FEV(1), FEF(25-75%) and FVC) percentiles. Tumor necrosis fa ctor was not measurable in any serum sample. Serum leukotriene B-4 (LT B(4)) levels were significantly reduced by n-3 fatty acids, mean reduc tion (-177 pg/mL) compared to n-6 fatty acids (+63 pg/mL) P < 0.05. Th ese results show that both n-3 fatty acids are absorbed and incorporat ed into platelet phospholipids in patients with CF and reduced serum L TB(4). No significant clinical differences or adverse effects were fou nd. Pediatr Pulmonol. 1994; 18:211-217. (C) 1994 Wiley-Liss, Inc.