The absorption and effect of dietary supplementation with omega-3 fatty acids on serum leukotriene B4, in patients with cystic fibrosis


  • Presented in part at the Federation of American Societies for Experimental Biology, New Orleans, Louisiana, 1993, and at the XVII World Congress on Diseases of the Chest, Amsterdam, The Netherlands, June 1993.


The substitution of omega-3 (n-3) fatty acids for omega-6 (n-6) fatty acids generates eicosanoids with diminished inflammatory effects. As the lungs of patients with cystic fibrosis (CF) are in a state of chronic 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, double-blind, crossover study in which 14 patients with CF (age: 6–16 years, mean 10.5 years; baseline Shwachman-Brasfield scores: 41–88, mean 76.7) received 6 weeks of n-3 ethyl ester concentrate from menhaden oil (100–131 mg/kg/day, mean 112.8) or n-6 fatty acids from safflower oil (102–132 mg/kg/day, mean 113.3), followed by a washout period of 6 weeks, and then 6 weeks of the other supplement. Analysis by gas chromatography showed that n-3 supplementation resulted in increased eicosapentaenoic 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 statistically significant differences were found (ANOVA, P >0.05) in Shwachman-Brasfield scores, sweat test, weight change, or forced expiratory volume and flow (FEV1, FEF25,75%, and FVC) percentiles. Tumor necrosis factor was not measurable in any serum sample. Serum leukotriene B4 (LTB4) levels were significantly reduced by n-3 fatty acids, mean reduction (−177 pg/mL) compared to n-6 fatty acids (+63 pg/mL) P < 0.05. These results show that both n-3 fatty acids are absorbed and incorporated into platelet phospholipids in patients with CF and reduced serum LTB4. No significant clinical differences or adverse effects were found.Pediatr Pulmonol. 1994;18:211–217. ©1994 Wiley-Liss, Inc.