TUESDAY, Feb. 10, 2026 (HealthDay News) -- Greater intake of caffeinated coffee and tea is associated with lower dementia risk, according to a study published online Feb. 9 in the Journal of the American Medical Association.Yu Zhang, M.B.B.S., from the T.H. Chan School of Public Health in Boston, and colleagues conducted a prospective cohort study involving 86,606 women from the Nurses' Health Study (NHS) and 45,215 men from the Health Professionals Follow-up Study to examine the association of tea and coffee intake with dementia risks and cognitive function.The researchers identified 11,033 cases of incident dementia among 131,821 participants during up to 43 years of follow-up. Higher caffeinated coffee intake was significantly associated with lower dementia risk (hazard ratio, 0.82) and a lower prevalence of subjective cognitive decline (prevalence ratio, 0.85), after adjustment for potential confounders and pooling across cohorts. Higher caffeinated coffee intake was also associated with better objective cognitive performance in the NHS cohort; participants in the highest versus the lowest quartile had a higher mean Telephone Interview for Cognitive Status score and a higher mean global cognition score, though the association with global cognition was not significant. Similar associations with these cognitive outcomes were seen for higher intake of tea, while no association was seen for decaffeinated coffee."It's important to remember that the effect size is small and there are lots of important ways to protect cognitive function as we age. Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle," senior author Dong D. Wang, M.D., Sc.D., also from the T.H. Chan School of Public Health, said in a statement.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter