Research suggests that carotenoids, naturally occurring pigments found in red, yellow, orange, and dark green fruits and vegetables, have protective associations with cognitive function. A study based on 16,010 female participants in the Nurses’ Health Study reported that those with higher mean intakes of carotenoids over 15 years had better overall cognition at older ages, and slower cognitive decline measured by neuropsychological testing. A follow-up study recently published in The Journal of Nutrition replicated and expanded the Nurse’s Health Study on carotenoids and cognitive function, with an additional decade of follow-up and the collection of repeated subjective cognitive measures among 49,493 women.
The objective of this study, conducted by Changzheng Yuan (Zhejiang University School of Medicine) and colleagues at Harvard T.H. Chan School of Public Health, was to examine prospectively long-term intakes of dietary carotenoids in relation to subjective cognitive function. Mean intakes of dietary carotenoids were calculated from 7 repeated food frequency questionnaires collected in 1984, 1986, and every 4 years afterward until 2006. Self-reported subjective cognitive function was assessed by a 7-item questionnaire on changes in memory and cognition. The mean subjective cognitive function scores, assessed in 2012 and 2014, were categorized as good, moderate, and poor.
Higher intake of total dietary carotenoids was associated with a substantially lower risk of moderate or poor cognitive function. Among the 49,493 US female nurses followed from middle to late adulthood, a long-term higher intake of total carotenoids was associated with 14% lower odds of moderate subjective cognitive function and 33% lower odds of poor subjective cognitive function in later life. These findings support the hypothesis that carotenoid intake over a period of many years may be most relevant to cognitive outcomes in later life because cognitive decline begins decades before symptom onset. The present study is the largest and longest evaluation of long-term intakes of multiple carotenoids in relation to subjective cognitive function. This relatively simple and promising means of maintaining brain health warrants further research to establish the optimal combination and intakes of dietary carotenoids for the prevention of cognitive decline.
Reference Yuan C, Fondell E, Ascherio A, Okereke OI, Grodstein F, Hofman A, Willett, WC. Long-Term Intake of Dietary Carotenoids Is Positively Associated with Late-Life Subjective Cognitive Function in a Prospective Study in US Women. The Journal of Nutrition, Volume 150, Issue 7, July 2020, Pages 1871–1879, https://doi.org/10.1093/jn/nxaa087.
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