Dietary carotenoid intake in relation to prevalent breast cancer and all-cause mortality among U.S. women: cross-sectional and prospective analyses of NHANES 2003–2018

Evidence regarding the associations of dietary carotenoid intake with prevalent breast cancer and subsequent all-cause mortality remains inconclusive. We examined the associations of five major dietary carotenoids with prevalent breast cancer and all-cause mortality among U.S. women. This study included 11,217 female participants from the NHANES 2003–2018 cycles. Dietary intakes of five carotenoids were assessed using two 24-hour dietary recalls. Survey-weighted logistic regression was used to examine the cross-sectional association between dietary carotenoid intake and prevalent breast cancer. Survey-weighted Cox proportional hazards regression was used to evaluate the prospective association between carotenoid intake and all-cause mortality. All analyses accounted for the NHANES complex sampling design, including sampling weights, masked variance strata (SDMVSTRA), and masked variance primary sampling units (SDMVPSU). After full adjustment, dietary carotenoid intake was not consistently associated with prevalent breast cancer. Among 11,203 linkage-eligible women, 1,074 deaths occurred during a median follow-up of 109 months. Compared with Q1, Q4 intakes of β-carotene and lutein plus zeaxanthin were associated with lower all-cause mortality (HR, 0.72; 95% CI, 0.58–0.89 and HR, 0.67; 95% CI, 0.54–0.83, respectively). Findings for α-carotene were inconsistent, and no robust associations were observed for β-cryptoxanthin or lycopene. Dietary carotenoid intake was not consistently associated with prevalent breast cancer. Higher β-carotene and lutein plus zeaxanthin intakes were associated with lower subsequent all-cause mortality; however, these observational findings do not establish causality.