The Science of Sip: How Caffeinated Coffee and Tea Lower Dementia Risk

Introduction

A groundbreaking study published in JAMA in February 2026 has provided the most definitive evidence yet linking caffeinated beverage consumption to cognitive health. For decades, the relationship between coffee, tea, and dementia remained a subject of debate. However, this massive prospective cohort study involving over 131,000 participants has clarified the impact of caffeine on the aging brain.

The Findings: Caffeine vs. Decaf

The research, which followed participants for up to 43 years, revealed a striking distinction between caffeinated and decaffeinated beverages. High intake of caffeinated coffee was associated with an 18% lower risk of dementia compared to low intake.

Crucially, decaffeinated coffee showed no such protective effect, suggesting that caffeine itself, or compounds specifically preserved alongside it, plays a vital role in neuroprotection.

Optimal Dosage for Brain Health

According to the dose-response analysis, you don't need to overdo it to see benefits. The most pronounced associations were observed at:

• Caffeinated Coffee: 2 to 3 cups per day.
• Tea: 1 to 2 cups per day.

Subjective and Objective Cognitive Benefits

Beyond reducing the risk of clinical dementia, higher caffeine intake was linked to:

1. Lower Subjective Cognitive Decline: Participants reported fewer perceived issues with memory and focus.
2. Better Objective Performance: In the Nurses' Health Study (NHS) cohort, those with higher caffeine intake performed significantly better on telephone-based neuropsychological tests.

Conclusion

While more research is always needed to understand the underlying biological mechanisms, the evidence from 2026 suggests that your daily ritual of caffeinated coffee or tea is doing more than just waking you up—it might be protecting your brain for the long haul.

Source: Zhang Y, et al. Coffee and Tea Intake, Dementia Risk, and Cognitive Function. JAMA. 2026 Feb 9. PMID: 41661604.