Associations of dietary copper intake with total bone mineral density and lumbar spine bone mineral density in American adults

Limited research has been conducted on the correlation between dietary copper intake and bone mineral density (BMD). In this study, we aimed to investigate the relationship between dietary copper intake and total BMD as well as lumbar spine BMD in American adults aged 20 to 59 years. In the National Health and Nutrition Examination Survey from 2011 to 2018, we included 1515 men and 1477 women as study participants. The study focused on the impact of dietary copper intake as the independent variable, and explored its relationship with total BMD and lumbar spine BMD as the outcome variables. Multivariate linear regression models were utilized to analyze this association, with further stratified analyses conducted based on gender and race. After correcting for relevant covariates, dietary copper intake was found to be positively associated with total (β = 0.0081, 95% CI: 0.0049–0.0113) and lumbar spine BMD (β = 0.0075, 95% CI: 0.0026–0.0124). A positive correlation between dietary copper intake and total BMD was observed in both men (β = 0.0069, 95% CI: 0.0027–0.0112) and women (β = 0.0098, 95% CI: 0.0047–0.0149) across various ethnic groups, with the exception of Non-Hispanic Black individuals. Dietary copper intake showed a significant positive association with lumbar spine BMD in women (β = 0.0122, 95% CI: 0.0043–0.0201), while this relationship was not statistically significant in men (β = 0.0045, 95% CI: −0.0018 to 0.0108). Furthermore, dietary copper intake was found to be significantly and positively associated with lumbar spine BMD in Mexican American (β = 0.0149, 95% CI: 0.0043–0.0255) and Other Race (β = 0.0124, 95% CI: 0.0016–0.0233) individuals. Our study demonstrated a positive correlation between dietary copper intake and total BMD as well as lumbar spine BMD in American adults. This suggests that moderate dietary copper intake could potentially lower the risk of osteoporosis.