United States: The levels of blood lutein+zeaxanthin and beta-cryptoxanthin were shown to be inversely related to incident all-cause dementia, says an article published in Neurology.
Carotenoids and Serum antioxidant vitamins may defend against age-related neurodegeneration. As a result, May A. Beydoun and colleagues investigated the links between these dietary indicators and incident all-cause and Alzheimer's disease (AD) dementia in middle-aged and older persons.

Researchers examined the associations and interactions of serum vitamins A, C, and E, as well as total and individual serum carotenoids, with incident AD and all-cause dementia using data from the third National Health and Nutrition Examination Surveys (1988–1994) and Centers for Medicare & Medicaid follow-up data. The Cox proportional hazards regression models were run.
The key findings of this study were as follows:
1. After 26 years of follow-up, serum lutein+zeaxanthin was linked with a lower risk of all-cause dementia (65+ age group), even in the lifestyle-adjusted model, but not in the SES–adjusted model.
2. For age- and sex-adjusted models, an inverse connection was found between serum beta-cryptoxanthin (per SD increase) and all-cause dementia (45+ and 65+), with the link staying robust in SES-adjusted models but weakening in successive models.
3. At lower levels of other carotenoids or antioxidant vitamins, antagonistic interactions imply that the predicted protective benefits of one carotenoid may be detected.
In conclusion, this study presents Class II evidence that blood lutein+zeaxanthin and beta-cryptoxanthin levels are inversely related to the incidence of all-cause dementia.
Over a 16-year period, researchers studied over 7,000 adults aged 45 and older and discovered that high blood levels of the antioxidants lutein, zeaxanthin, and beta-cryptoxanthin, which are found in leafy green vegetables and peas, as well as oranges and papaya, may be associated with a lower risk of dementia.
More research with time-dependent exposures and randomized trials are needed to investigate the neuroprotective benefits of dietary supplementation with specific carotenoids.
Reference:
Beydoun, M. A., Beydoun, H. A., Fanelli-Kuczmarski, M. T., Weiss, J., Hossain, S., Canas, J. A., Evans, M. K., & Zonderman, A. B. (2022). Association of Serum Antioxidant Vitamins and Carotenoids With Incident Alzheimer Disease and All-Cause Dementia Among US Adults. In Neurology (Vol. 98, Issue 21, pp. e2150–e2162). Ovid Technologies (Wolters Kluwer Health). https://doi.org/10.1212/wnl.0000000000200289