Fish oil blunts lung function decrements induced by acute exposure to ozone in young healthy adults: A randomized trial
Abstract
Rationale: Over one-third of the U.S. population is exposed to unsafe levels of ozone (O3). Dietary supplementation with fish oil (FO) or olive oil (OO) has shown protective effects against other oxidant pollutants.
Objectives: To evaluate potential respiratory and cardiovascular benefits of FO or OO supplementation against acute O3 exposure in healthy adults.
Methods: Forty-three healthy participants (26 ± 4 years old; 47% female) were randomized to receive either 3 g/day of FO, 3 g/day OO, or no supplementation (CTL) for 4 weeks prior to undergoing 2-hour exposures to filtered air and 300 ppb O3 with intermittent exercise on two consecutive days. Outcome measurements included spirometry, sputum neutrophil percentage, blood markers of inflammation, tissue injury and coagulation, vascular function, and heart rate variability. The effects of dietary supplementation and O3 on these outcomes were evaluated with linear mixed-effect models.
Measurements and main results: Compared with filtered air, O3 exposure decreased FVC, FEV1, and FEV1/FVC immediately post exposure regardless of supplementation status. Relative to that in the CTL group, the lung function response to O3 exposure in the FO group was blunted as evidenced by O3-induced decreases in FEV1 and FEV1/FVC values that were approximately 48% and 70% smaller, respectively. In contrast, inflammatory responses measured in the sputum immediately post O3 exposure were not different among the three supplementation groups. Systolic and diastolic blood pressure elevations 20-h post O3 exposure were blunted by OO supplementation.
Conclusions: FO supplementation appears to offer significant protection against lung function reduction caused by acute O3 exposure in healthy adults.