Associations of Dietary Carotenoids With Cognitive Decline: A Population-Based Prospective Study

Objectives: Evidence on the association between dietary carotenoids and cognitive decline was insufficient, especially among Asian populations. We examined the prospective association of dietary intakes of total and individual carotenoids with cognitive decline among Chinese middle-aged and older adults. Methods: This prospective study included 4043 participants aged 55 years and older from the China Health and Nutrition Survey (CHNS) from 1997 to 2006. Average daily intakes of dietary carotenoids (total carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein-zeaxanthin) were calculated from 3-day 24-hour dietary recalls. Cognitive function was repeated measured using the Telephone Interview for Cognitive Status-Modified (TICS-m). Beta coefficients (β) and the 95% confidence intervals (CI) were estimated by linear mixed-effects models to evaluate the association of energy-adjusted carotenoids with cognitive decline (z-score). Results: Higher intake of total dietary carotenoids was associated with slower cognitive decline after controlling for sociodemographic characteristics, lifestyle variables, and other dietary factors. Comparing the top to bottom quintiles (median intake: 36.9 vs 3.0 mg/d) of total carotenoids, the adjusted difference in decline rates (95% CI) was 0.020 (0.003, 0.037)/year. The strongest association was observed in the fourth quintile (median intake: 23.6 mg/d) with the difference in decline rates (95% CI) being 0.033 (0.015, 0.050)/year. Similar protective associations were found for individual carotenoids, including α-carotene (βQ5 VS Q1=0.041, 95% CI: 0.023, 0.058), β-cryptoxanthin (β=0.034, 95% CI: 0.017, 0.052), lutein-zeaxanthin (β=0.022, 95% CI: 0.004, 0.039), lycopene (β=0.021, 95% CI: 0.004, 0.038) and β-carotene (β=0.020, 95% CI: 0.002, 0.037). Conclusions: Our findings support the potential beneficial roles of dietary carotenoids in slowing cognitive decline in Chinese middle-aged and older adults. Further research is warranted to explore the optimal intake level for dietary intervention and to investigate the underlying mechanisms. Funding Sources: This work was supported by the National Natural Science Foundation of China (No. 8210120183).