Dietary fish oil supplementation may reduce oxidative stress and inflammatory skin responses in individuals exposed to fine particulate air pollution for short periods of times, according to study results published in the British Journal of Dermatology.
Exposure to fine particulate matter with an aerodynamic diameter ≤2.5 μm (PM2.5) may represent a risk factor for certain inflammatory skin diseases.
In this study, 65 healthy college students (58.5% women) in Shanghai, China exposed to average PM2.5 concentrations of 34.68±15.83 μg/m3 per 24-hour period were randomly assigned to receive dietary supplementation with marine fish oil (60% omega-3 fatty acids: eicosapentaenoic acid and docosahexaenoic acid; n=24; mean age, 23.02±2.26 years) or placebo (sunflower seed oil; n=31; mean age, 22.87±1.28 years) for a period of 4 months. The marine fish oil and placebo groups had comparable demographic characteristics.
Participants were instructed to take capsules twice daily. Biomarkers of skin inflammation were collected at baseline and after 8, 12, and 14 weeks of dietary supplementation with tape stripping. Biomarkers of interest included interleukin (IL)-1α, IL-1 receptor antagonist, carbonyl protein, total antioxidant capacity, and glutathione.
To account for potential lagged effects of PM2.5 exposure, biomarker concentrations were determined for 4 different periods of PM2.5 exposure before skin sampling: 0 to 6 hours, 0 to 12 hours, 0 to 24 hours, and 0 to 48 hours. Real-time concentrations of ambient PM2.5 were measured throughout the trial duration using an environmental dust monitor. Linear mixed effect models were used to assess the relationship between PM2.5 exposure and biomarker concentrations in each both groups. Analyses were adjusted for gaseous pollutant concentrations and dietary nutrient intake.
The average 24-hour PM2.5 concentration prior to skin sampling was 34.68±15.83 μg/m3. For each 10 μg/m3 increase in PM2.5 concentration, IL-1α levels increased by 15.0% in the placebo group and were reduced by 26.54% in the fish oil group (P =.03), and carbonyl protein levels increased by 16.30% in the placebo group and decreased by 5.71% in the fish oil group (P <.01). These results suggest that patients taking fish oil may have experienced reduced inflammation in response to increased PM2.5 concentrations. However, the groups did not differ significantly on other biomarkers.
Study limitations include a small and homogenous cohort, the use of a fixed-site monitor vs personal device to measure PM2.5 exposure, and the fact that exposure levels may have varied between participants.
“Our findings [suggest] that dietary fish-oil supplementation might serve as a simple and effective way to protect skin health against exposure to ambient PM2.5 in areas with severe air pollution,” noted the study authors.
Lin Z, Niu Y, Jiang Y, et al. Protective effects of dietary fish-oil supplementation on skin inflammatory and oxidative stress biomarkers induced by fine particulate air pollution: a pilot randomized, double-blind, placebo-controlled trial [published online April 25, 2020]. Br J Dermatol. doi: 10.1111/bjd.19156