Fish Oil Supplementation in Overweight/Obese Patients with Uncontrolled Asthma. A Randomized Trial.

Omega-3 fatty acid (n3PUFA) supplementation has been proposed as a promising antiasthma strategy. The rs59439148 polymorphism affects leukotriene production and possibly inflammatory responses to n3PUFA. Assess the effects of n3PUFA supplementation and genotype on asthma control in patients with obesity and uncontrolled asthma. This multicenter trial among 12- to 25-year-olds with overweight/obesity and uncontrolled asthma randomized subjects in a 3:1 allotment to n3PUFA (4 g/d) or soy oil control for 24 weeks. Asthma Control Questionnaire was the primary outcome; secondary outcomes included blood leukocyte n3PUFA levels, urinary leukotriene-E4, spirometry, and asthma-related events. The number of SP1 tandem repeats in rs59439148 determined genotype status. Simple and multivariable generalized linear models assessed effects on outcomes. Ninety-eight participants were randomized (77 to PUFA, 21 to control), and more than 86% completed all visits. Asthma and demographic characteristics were similar among treatment groups. n3PUFA treatment increased the n3-to-n6 PUFA ratio in circulating granulocytes ( = 0.029) and monocytes ( = 0.004) but did not affect mean Asthma Control Questionnaire change at 6 months (n3PUFA: mean, -0.09; 95% confidence interval [CI], 0.09 to 0.10; vs. control: mean, -0.18; 95% CI, -0.42 to 0.06;  = 0.58). Changes in urinary leukotriene-E4 ( = 0.24), forced expiratory volume in 1 second % predicted ( = 0.88), and exacerbations (relative risk [RR], 0.92; 95% CI, 0.30-2.89) at 6 months were similar in both groups. n3PUFA treatment was associated with reduced asthma-related phone contacts (RR, 0.34; 95% CI, 0.13-0.86;  = 0.02). genotype did not affect n3PUFA treatment responses. We did not find evidence that n3PUFA use improves most asthma-related outcomes and cannot recommend it as a prevention strategy for overweight/obese patients with asthma. Clinical trial registered with www.clinicaltrials.gov (NCT01027143).