Overview
- Drinking about 2–3 cups of caffeinated coffee or 1–2 cups of tea per day was associated with slower cognitive decline and the lowest dementia risk in the cohorts studied.
- The highest caffeinated coffee intake correlated with an 18% lower dementia risk and the highest tea intake with about a 14% lower risk after adjustments for confounders.
- Decaffeinated coffee showed no association with dementia risk, pointing researchers toward caffeine or caffeine-linked bioactive compounds as possible drivers of the signal.
- The findings draw on up to 43 years of follow-up in the Nurses’ Health Study and Health Professionals Follow-up Study, totaling 131,821 participants and 11,033 dementia cases.
- Associations were seen in participants with and without the APOE4 risk variant, appeared to plateau beyond moderate intake, and remain observational with modest effect sizes that do not change clinical guidance.