Overview
- The strongest association was seen with roughly two to three cups of caffeinated coffee a day or one to two cups of tea.
- Greater intake did not yield additional benefit, and decaffeinated coffee showed no significant association with dementia risk.
- Across 11,033 diagnosed cases, caffeinated beverage consumers also reported slightly fewer memory problems and performed marginally better on some cognitive tests.
- The association persisted after adjustment for numerous lifestyle and health factors and appeared consistent across genetic risk, including APOE4 carriers.
- The study is observational with self-reported intake and nonuniform case ascertainment in a predominantly white health‑professional cohort, and experts caution it should complement proven prevention behaviors.