Headlines screamed it everywhere: drinking two to three cups of coffee daily reduces dementia risk by 18%. A massive Harvard study of 131,000 people over 43 years seemed to settle it. But the real story is far more complicated—and reveals how observational research gets wildly misinterpreted. The study shows correlation, not causation. Worse, when researchers tested decaffeinated coffee—identical chemistry minus caffeine—it showed no benefit and even hinted at cognitive harm in some women. This smoking gun suggests the coffee drinkers weren't protected by what's in their cup, but by who they are: healthcare professionals with higher education, better health habits, and stronger cognitive reserve. Discover why this finding tells us almost nothing about whether you should start drinking coffee, and what the actual evidence for dementia prevention really shows.

A quick note—the opinions and analysis shared on Truth Seekers are our own interpretations of published research and should not be used as medical, financial, or professional advice. Always consult qualified professionals for decisions affecting your health or wellbeing.