Moderate consumption of coffee or tea may help protect the brain as we age, reducing the risk of developing dementia and slowing cognitive decline.

The Study and Its Findings

In a large cohort study conducted by experts from several scientific institutions, data from 131,821 participants in the Nurses' Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS) were analyzed. The research found that drinking 2–3 cups of caffeinated coffee or 1–2 cups of tea per day was associated with a lower risk of dementia, slower cognitive decline, and better preservation of mental functions. The study was published in the journal JAMA.

The Importance of Prevention and the Role of Beverages

Preventing dementia is becoming increasingly important, as current treatment methods are limited and usually have only a moderate effect once symptoms appear. As a result, researchers are paying more attention to lifestyle factors, including diet, that may influence the development of cognitive disorders. Coffee and tea contain polyphenols and caffeine, which are believed to support brain health by reducing inflammation and limiting cellular damage associated with cognitive decline.

Long-Term Observations

Data collected over more than 40 years allowed researchers to assess the impact of long-term coffee and tea consumption on brain health. Participants were followed for up to 43 years, with regular monitoring of their diets, dementia diagnoses, subjective cognitive complaints, and objective measures of mental abilities. The analysis compared the consumption of caffeinated coffee, tea, and decaffeinated coffee.

Main Conclusions

Among more than 130,000 participants, 11,033 were diagnosed with dementia during the observation period. Those who regularly drank caffeinated coffee had an 18% lower risk of developing dementia compared to those who rarely or never drank it. This group also showed lower rates of subjective cognitive decline (7.8% versus 9.5%) and better results in some objective tests. Similar patterns were observed among tea drinkers, while decaffeinated coffee did not show the same association, suggesting a possible key role for caffeine.

The most pronounced effects were seen in those who consumed 2–3 cups of caffeinated coffee or 1–2 cups of tea per day. Higher caffeine intake did not cause harm, but also did not provide additional benefits compared to moderate consumption.

Genetic Factors

Comparing people with different genetic predispositions to dementia showed that coffee and caffeine had the same effect on groups with both high and low genetic risk.

Conclusion

Although the effect of moderate coffee or tea consumption on reducing dementia risk is small, these beverages can be part of a comprehensive strategy to support cognitive health as we age. Further research is needed to confirm the mechanisms involved.