A study of over 130,000 individuals followed for up to 43 years suggests a correlation between moderate consumption of caffeinated coffee or tea and a reduced risk of dementia, as well as slower cognitive decline. The research, published in JAMA, analyzed data from the Nurses’ Health Study and the Health Professionals Follow-Up Study.
Investigators from Mass General Brigham, Harvard T.H. Chan School of Public Health and the Broad Institute of MIT and Harvard led the analysis. Researchers compared the influence of caffeinated coffee, tea, and decaffeinated coffee on dementia risk and cognitive health. The study identified a nonlinear inverse association between intake levels of caffeinated coffee and tea and both dementia risk and subjective cognitive decline.
The most pronounced benefits were observed with an intake of approximately two to three cups per day of caffeinated coffee, or one to two cups per day of tea, according to the findings. People who drank caffeinated coffee had a significantly lower rate of developing dementia—141 cases per 100,000 person-years—compared to those who did not, with 330 cases per 100,000 person-years observed in the comparison group, according to a report from Forbes.
Daniel Wang, senior author of the study and an associate scientist with the Channing Division of Network Medicine in the Mass General Brigham Department of Medicine, emphasized the importance of preventative measures. “When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention,” Wang said. He also noted that the study benefited from “unique access to high-quality data through studies that have been going on for more than 40 years.”
Researchers caution that the effect size is small and that numerous other factors contribute to cognitive health as people age. “While our results are encouraging, it’s key to remember that the effect size is small and Notice lots of important ways to protect cognitive function as we age. Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle,” Wang stated. The study highlights the potential for early prevention, given the limited effectiveness of current dementia treatments once symptoms manifest.
