This extensive longitudinal study tracked over 130,000 individuals for more than four decades to clarify how different hot beverages impact long-term brain health. The researchers discovered that regular consumption of caffeinated coffee and tea is linked to a statistically significant reduction in dementia risk and better preservation of mental clarity. Interestingly, these protective benefits were most evident at moderate intake levels, specifically around two to three cups of coffee or one to two cups of tea daily. Conversely, the data revealed that decaffeinated coffee offered no such advantages, suggesting that caffeine or specific compounds associated with it play a vital role in maintaining cognitive function as we age.