A substantial prospective cohort investigation has indicated that moderate consumption of beverages containing caffeine, specifically 2-3 servings of coffee or 1-2 servings of tea daily, is associated with a diminished risk of dementia and a slight enhancement in cognitive capabilities. Conversely, decaffeinated coffee demonstrated no discernible protective impact.
Zhang et al. determined that moderate caffeinated coffee and tea intake can lower dementia risk. Image credit: Sci.News.
Given the current limitations in dementia treatments, which often provide only marginal benefits once symptoms manifest, early intervention strategies are paramount.
The emphasis on preventative measures has prompted researchers to explore the role of lifestyle determinants, such as dietary habits, in the pathogenesis of dementia.
Coffee and tea are rich in bioactive compounds, including polyphenols and caffeine, which have been posited as potential neuroprotective agents. These substances may mitigate inflammation, reduce cellular damage, and offer protection against cognitive deterioration.
Despite promising indications, the existing evidence regarding the connection between coffee consumption and dementia has been marked by inconsistencies. This is partly attributable to limitations in study follow-up periods and insufficient detail to accurately capture long-term consumption patterns, variations across beverage types, or the full spectrum of health outcomes.
“In our pursuit of potential dementia prevention strategies, we considered the widespread consumption of coffee as a promising dietary intervention. Our unique access to high-quality data spanning over four decades allowed us to rigorously investigate this hypothesis,” stated Dr. Daniel Wang, a researcher affiliated with the Department of Medicine at Mass General Brigham, Harvard Medical School, and the Broad Institute.
“While our findings are encouraging, it is essential to acknowledge that the magnitude of the effect is modest. Furthermore, numerous other vital strategies exist for preserving cognitive function as individuals age.”
“Our investigation suggests that the consumption of caffeinated coffee or tea can serve as one component within a broader approach to cognitive health maintenance.”
Dr. Wang and his research team meticulously analyzed data encompassing 131,821 participants from both the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS).
The study’s objective was to compare the influence of caffeinated coffee, tea, and decaffeinated coffee on the risk of developing dementia and the cognitive health status of each participant.
Among the extensive cohort of over 130,000 individuals, a total of 11,033 participants were diagnosed with dementia.
Both male and female participants who reported the highest levels of caffeinated coffee intake exhibited an 18% reduction in their risk of dementia when contrasted with individuals who consumed little to no caffeinated coffee.
Individuals who regularly drank caffeinated coffee also demonstrated a lower incidence of subjective cognitive decline, recorded at 7.8% compared to 9.5%.
By specific assessment metrics, participants who consumed caffeinated coffee also performed better on objective evaluations of overall cognitive function.
An elevated intake of tea yielded comparable positive outcomes, whereas decaffeinated coffee did not produce similar effects. This observation implies that caffeine might be the primary active agent responsible for these neuroprotective benefits, although further scientific inquiry is necessary to confirm the exact contributing factors and underlying mechanisms.
The most significant cognitive advantages were observed in participants who consumed between 2-3 cups of caffeinated coffee or 1-2 cups of tea on a daily basis.
Contrary to the conclusions of several prior research efforts, increased caffeine consumption did not result in adverse effects; instead, it conferred neuroprotective advantages comparable to those associated with the optimal intake levels.
“We also conducted a comparative analysis among individuals with varying genetic predispositions to developing dementia and observed consistent results. This suggests that coffee or caffeine is likely to offer equitable benefits to individuals irrespective of their genetic susceptibility to dementia,” noted Yu Zhang, a Ph.D. candidate at the Harvard Chan School and a research trainee at Mass General Brigham.
The research findings are published in the Journal of the American Medical Association.
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Y. Zhang et al. Coffee and Tea Intake, Dementia Risk, and Cognitive Function. JAMA, published online February 9, 2026; doi: 10.1001/jama.2025.27259
