After an analysis of health data from over 131,000 people tracked for up to 43 years, researchers found that drinking coffee and tea daily seems to guard against the development of Alzheimer's disease and other forms of cognitive decline.

In one of the largest prospective cohort studies to date, moderate consumption of caffeinated coffee (2-3 cups a day) or tea (1-2 cups a day) correlated with reduced dementia risk and modest improvements in cognitive function, although decaffeinated coffee showed no protective effect.