Regular coffee or tea drinkers may have reason to celebrate: a major new study indicates that moderate caffeine consumption could help protect the brain against dementia.

Researchers followed 131,821 participants for up to 43 years, tracking their coffee and tea intake alongside cognitive health. The findings, published in JAMA, showed that people who consumed two to three cups of coffee or one to two cups of tea daily had a lower risk of developing dementia compared with those who consumed little or no caffeine.

Lower Risk, But Not More Always Better

  • Drinking 1–5 cups of coffee daily was linked to a roughly 20% lower risk of dementia.
  • Consuming at least one cup of tea daily corresponded to a 15% lower risk.
  • Benefits peaked around 2.5 cups of coffee per day, with higher amounts offering no extra protection.

Experts note that while the study shows a strong association, it does not prove that caffeine directly prevents dementia. The results remained significant even after adjusting for factors such as chronic diseases, medication use, diet, socioeconomic background, BMI, smoking, and mental health.

Why Caffeine Might Help

Researchers suggest several possible explanations for caffeine’s protective effects:

  • Reducing neuroinflammation in the brain.
  • Improving vascular function.
  • Enhancing insulin sensitivity, lowering the risk of diabetes—a known dementia risk factor.

Participants who consumed more caffeine also reported fewer memory complaints and performed slightly better on cognitive tests.

Moderation Matters

While no negative effects were observed at higher consumption levels in this study, other research shows that excessive caffeine may disrupt sleep or increase anxiety. Adding large amounts of sugar or milk may also reduce the health benefits.

The protective link was strongest in people under 75, suggesting that habits formed by middle age could have the most impact over decades.

Bottom Line

The research does not mean that non-coffee or tea drinkers must start, but for those who already enjoy caffeine, the findings are encouraging. For newcomers, experts advise starting with small, moderate amounts, emphasizing consistency and balance over excess.