Association Between Fish Oil Supplements and Per- And Polyfluoroalkyl Substances (PFAS)

Lauren Barnes ’22

Student: Lauren Barnes ’22
Research Mentor: Elizabeth Kantor (Memorial Sloan Kettering Cancer Center Department of Biostatistics and Epidemiology)

Per- and polyfluoroalkyl substances (PFAS) are a class of pollutants associated with various health concerns. One of the most common sources of PFAS in our bodies is seafood consumption — PFAS enter waterways, the fish living in those waters, and finally the humans who eat the fish. Our study used survey data to examine whether or not regular use of fish oil supplements made from those same fish also contributed to PFAS levels in Americans.

Per- and polyfluoroalkyl substances (PFAS) are widespread pollutants and associated with a variety of potential health concerns such as decreased immune response. Although fish consumption has been associated with increased PFAS levels, little is known about the association between fish oil and PFAS. For this study, we examined associations between fish oil supplement use and serum PFAS levels. This analysis includes 4,672 U.S. adults, ages 25 and older, surveyed from 2007-2014 as part of the National Health and Nutrition Examinations Survey (NHANES). Fish oil supplement use over the prior 30 days was assessed during an in-home interview, and defined as follows: no use, low use (<1 serving/day), and high use (1+ serving/day). Outcomes include four serum PFAS compounds: PFOS, PFOA, PFNA, and PFDE. To determine the association between fish oil use and log-transformed PFAS levels, survey-weighted linear regression was used to evaluate the multivariate-adjusted ratios between supplement-users’ and non-users’ geometric mean PFAS concentrations. Compared to no use of fish oil supplements, high use was inversely associated with PFOS levels (ratio = 0.88; 95% CI = 0.77, 0.997), with no association observed for PFOA, PFNA, and PFDE. Associations pertaining to PFOA varied by survey cycle (p-interaction = 0.048), but fish oil use was not significantly associated with PFOA levels in any survey cycle. Results did not vary significantly by age or sex. However, fish oil supplement use was significantly associated with lower PFOS levels in female participants (p-trend=0.03), but not male participants. Fish oil supplements were inversely associated with PFOS levels- an association driven by female participants. Fish oil use was not associated with the other PFAS examined. Future work is needed to determine if this pattern of association reflects a true association, residual confounding, or chance.