A study spanning over four decades has shown that moderate consumption of caffeinated coffee or tea may be linked to a lower risk of dementia and the preservation of mental abilities. The results of this study were published in the JAMA journal, highlighting caffeinated beverages as a potential element in dementia prevention strategies.
The study, which involved more than 130,000 people, was conducted by research teams from Mass General Brigham, Harvard T.H. Chan School of Public Health, and the Broad Institute, which is affiliated with both the Massachusetts Institute of Technology and Harvard. It was based on data from two large cohort studies: the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS).
According to the scitechdaily website, the analysis revealed that consuming caffeinated coffee at a rate of 2-3 cups per day or tea at 1-2 cups per day was associated with an 18% lower risk of developing dementia compared to individuals who did not consume these drinks or consumed them in small quantities. Additionally, coffee drinkers reported a slower rate of self-perceived cognitive decline (7.8% vs. 9.5%), and some objective tests showed better performance among them.
Dr. Daniel Wang, a co-investigator and an assistant professor at Harvard Medical School, said: "When looking for potential tools to prevent dementia, we thought that something as common as coffee might be a promising dietary intervention. Having access to high-quality data over more than 40 years allowed us to follow up on this idea."
Wang emphasized that the results are encouraging, but they do not mean that coffee or tea is the sole solution for protecting the brain. There are several other important ways to maintain mental functions as one ages.
The study focuses on preventing dementia before the onset of symptoms, as current treatments offer limited improvements after the disease has developed.
Both coffee and tea contain biologically active compounds such as caffeine and polyphenols, which may reduce inflammation and limit the cellular damage associated with cognitive decline.
The researchers noted that the benefits were clearly seen in people who consumed 2-3 cups of coffee or 1-2 cups of tea daily, whereas decaffeinated coffee did not show the same effects, suggesting a potential role for caffeine. Furthermore, higher levels of consumption did not show any harmful effects, and larger quantities seemed to provide similar neuroprotective benefits as the optimal range.
The lead researcher, Yu Zhang, a doctoral student at the Harvard Chan School and a research fellow at Mass General Brigham, pointed out: "The results were similar among people with both high and low genetic risk for dementia, which means that coffee or caffeine is likely beneficial for all genetic groups."
The study included follow-up on some participants for up to 43 years, giving the researchers a rare opportunity to analyze the long-term relationship between caffeinated beverage consumption and mental health.
