Plant food intake is associated with lower cadmium body burden in middle-aged adults

Purpose Dietary intake is a primary source of cadmium (Cd) exposure in the non-smoking population. Plant foods containing metal-binding plant compounds such as polyphenols, phytates, and phytochelatins may reduce Cd bioavailability and result in lower Cd body burden. In this study, we investigated the association between plant food intake and urinary creatinine-adjusted Cd (uCd), a well-established marker of Cd body burden. Methods Participants were from a cross-sectional sample of 1901 adults in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. Dietary intake was assessed with a food frequency questionnaire. We created a 12-point plant food score (PFS) based on reported intake across seven categories (fruits, vegetables, legumes, nuts/seeds, whole grains, tea, and wine). Higher scores indicated higher consumption and diversity of plant food intake. Multivariable linear regression models were used to estimate the association between PFS and uCd. Due to the influence of age and smoking on Cd status, stratified analyses were conducted. Results Mean PFS was 5.4 (SD 2.2) and mean uCd was 0.53 µg/g creatinine (SD 0.39). In adjusted models, PFS was not associated with uCd ( p > 0.05). In stratified analyses, PFS was inversely associated with uCd ( p = 0.047) with a 1-point higher PFS associated with 0.018 µg/g lower uCd among middle-aged (45–59) adults. No significant association was observed between PFS and uCd in older (≥ 60) adults. The association of PFS and uCd did not differ by smoking status. Conclusion Our findings suggest higher plant food intake is associated with lower Cd body burden in middle-aged but not older adults.