Objectives – Worldwide, coffee and tea are two of the most popular beverages. Studies suggests they have a protective role and reduce the risk of cognitive decline. We aimed to assess the relationship between their intake and cognitive decline.

Methods – Cognitively unimpaired (n=8,451) from UK BioBank (≥60 years) with at least 2 follow up visits (average follow up time 8.83 years) were included. Participants completed baseline self-report coffee and tea intake, and cognitive assessment including Pairs Matching test, Reaction Time test, Numeric Memory test, and Fluid Intelligence.

Key findings – Linear mixed models (including potential confounders) showed those both never consuming coffee and those with moderate coffee consumption (1-3 cups) had slower declines in Fluid Intelligence compared to those with high coffee consumption (³4 cups, β=0.06, SE=0.02, p=.005; β=0.07, SE=0.02, p<.001, respectively).

Those who never drank tea showed a greater decline in Fluid Intelligence compared to those who had moderate and high tea consumption (β=0.06, SE=0.02, p=.009; β=0.06, SE=0.02, p=.003), respectively).

Conclusions - Coffee and tea drinking may be a protective factor against cognitive decline, particularly for maintaining Fluid Intelligence. There is an upper limit for beneficial effects of coffee intake (maximum 3 cups per day), and no coffee intake is more beneficial than 4 or more cups. Conversely, high tea consumption provided positive effects on cognition in addition to moderate consumption, with high tea consumption being more beneficial than no tea consumption. Additional longitudinal observational and intervention studies are required to validate our findings and confirm this hypothesis.