Enjoying a daily cup of coffee or tea may offer more than just a morning energy boost, according to groundbreaking research that suggests these popular beverages could play a role in protecting brain health as people age. A thorough study published in JAMA analyzed 131,821 participants from the Nurses’ Health Study and Health Professionals Follow-Up Study, tracking them for up to 43 years to examine the relationship between caffeine consumption and cognitive health.
The findings reveal encouraging news for coffee and tea drinkers. Researchers identified 11,033 incident dementia cases during the study period and discovered that higher caffeinated coffee intake was linked to an 18% lower dementia risk. Participants consuming the most caffeinated coffee showed 141 dementia cases per 100,000 person-years, compared to 330 cases among those drinking the least.
The most favorable amount appeared to be two to three cups of caffeinated coffee daily, which also correlated with reduced subjective cognitive decline, dropping from 9.5% to 7.8% prevalence. In the Nurses’ Health Study, higher caffeinated coffee intake was also associated with better performance on objective cognitive tests, including higher scores on the Telephone Interview for Cognitive Status.
Tea drinkers experienced similar neuroprotective benefits, with one to two cups of caffeinated tea daily showing the greatest cognitive advantages. The study demonstrated a nonlinear inverse dose-response relationship between tea consumption and both dementia risk and cognitive decline, suggesting that moderate intake provides meaningful protection.
Importantly, decaffeinated coffee showed no association with lower dementia risk or improved cognitive function, strongly suggesting that caffeine itself serves as the key active factor in these neuroprotective effects. Researchers propose that caffeine reduces inflammation and cellular damage, while polyphenols in both beverages support heart health, gut function, and blood sugar regulation. However, the authors caution that excessive caffeine consumption can cause anxiety, rapid heart rate, and digestive issues.
While these results are promising, the researchers emphasize important limitations. As an observational study, it demonstrates association rather than causation. The risk reduction translates to approximately a half-year delay in cognitive aging, and potential confounders like blood pressure effects require consideration.
Self-reported intake measurements also present inherent challenges.
With dementia cases expected to double in the United States due to an aging population, prevention strategies become increasingly critical. This research adds to growing evidence supporting caffeine’s role in cognitive preservation, offering a simple, accessible approach alongside established recommendations for healthy diet and regular exercise. Adequate sleep and emotional regulation are also important for brain health, and prioritizing sleep quality can support cognitive resilience as people age.
