Moderate morning coffee linked to lower dementia risk and improved mood

A large U.S. cohort study of 131,821 nurses tracked over up to 43 years found that consuming two to three cups of caffeinated coffee or tea daily was associated with a 35% reduction in dementia risk, particularly among adults younger than 75. The protective effect plateaued at moderate intake, and higher consumption did not add further benefit. Researchers suggest caffeine may protect brain cells by blocking adenosine, reducing inflammation, and limiting amyloid plaque buildup. Decaffeinated coffee drinkers showed faster memory decline, likely reflecting underlying health issues.

Separate German experience‑sampling research involving 236 participants examined the timing of coffee consumption on mood. The authors reported that “the association between caffeine consumption and positive affect was strongest within the first 2.5 hours after awakening,” with a smaller boost observed 10–12.5 hours after waking. The study found no timing effect on negative mood outcomes. Earlier research cited from the European Heart Journal also linked morning coffee consumption to a 16% lower risk of all‑cause mortality and a 31% lower risk of cardiovascular death, whereas coffee taken throughout the day showed no mortality benefit.

Overall, the evidence suggests that moderate coffee intake—especially in the early morning—may contribute to better cognitive health and mood, while excessive or late‑day consumption offers no additional advantage.