Seafood, wine, rice, vegetables, and other food items associated with mercury biomarkers among seafood and non-seafood consumers: NHANES 2011–2012

Fish/seafood consumption is a source of mercury; other dietary sources are not well described. This cross-sectional study used National Health and Nutrition Examination Survey (NHANES) 2011–2012 data. Participants self-reported consuming fish/seafood (N=5427) or not (N=1770) within the past 30 days. Whole blood total mercury (THg), methylmercury (MeHg) and urinary mercury (UHg) were determined. Diet was assessed using 24-hour recall. Adjusted regression models predicted mercury biomarker concentrations with recent food consumption while controlling for age, sex, education, and race/ethnicity. Geometric mean THg was 0.89 μg/L (95% confidence interval (CI): 0.78, 1.02) (seafood consumers) and 0.31 μg/L (95% CI: 0.28, 0.34) (non-seafood consumers); MeHg and UHg concentrations follow similar patterns. In adjusted regressions among seafood consumers, significant associations were observed between mercury biomarkers with multiple foods, including fish/seafood, wine, rice, vegetables/vegetable oil, liquor and beans/nuts/soy. Among non-seafood consumers, higher THg was significantly associated with mixed rice dishes, vegetables/vegetable oil, liquor and approached statistical significance with wine (p<0.10); higher MeHg was significantly associated with wine and higher UHg was significantly associated with mixed rice dishes. Fish/seafood consumption is the strongest dietary predictor of mercury biomarker concentrations; however, consumption of wine, rice, vegetables/vegetable oil, or liquor may also contribute, especially among non-seafood consumers.