A long-term study following more than 130,000 participants over four decades links regular caffeine intake to lower dementia rates. Heavy coffee consumers show an 18% reduced risk of dementia compared to those with minimal intake. High tea drinkers experience a 16% drop in risk.

Study Details and Mechanisms

Researchers from Harvard Chan School analyzed healthcare workers, tracking their consumption of caffeinated coffee, tea, fizzy drinks, and chocolate. Caffeine combats brain inflammation and prevents buildup of harmful proteins that contribute to cognitive decline. Decaffeinated versions offer no such benefits, confirming caffeine as the key protective element.

Cognitive Benefits Observed

Higher caffeine levels associate with improved brain function and slower cognitive decline. Moderate intake yields the strongest protection, with diminishing returns at higher amounts. Over the 43-year period, 11,033 participants developed dementia.

Expert Insights

Lead researcher Yu Zhang, a PhD student at Harvard Chan School, states: “Caffeine is likely equally beneficial for people with high and low genetic risk of developing dementia.”

Senior researcher Dr. Daniel Wang from Mass General Brigham’s Department of Medicine adds: “While our results are encouraging, it’s important to remember that the effect size is small and there are lots of important ways to protect cognitive function as we age.”

Professor Tara Spires-Jones from the UK Dementia Research Institute notes: “This kind of observational research cannot prove conclusively that caffeine intake was the reason for lower dementia risk.”