Most people drink coffee for its ability to keep them alert and focused. However, new research suggests it may also help maintain brain health as we age.
A long-term study led by researchers from Mass General Brigham found that moderate consumption of caffeinated coffee or tea was associated with a lower risk of dementia and improved cognitive performance in participants over time. Their findings, published in JAMA, are based on more than forty years of dietary and health data and research.
Tracking Brain Health Over Four Decades
The MGB research team analyzed data from 131,821 participants in the Nurses’ Health Study and the Health Professionals Follow-Up Study, two large studies that have tracked diet, lifestyle, and health outcomes for more than four decades. This long-term dataset gave the researchers the perspective to examine how patterns of caffeine consumption relate to cognitive aging.
Participants regularly reported how much caffeinated and decaffeinated coffee and tea they drank. Researchers compared these habits with long-term outcomes such as diagnosed dementia, self-reported memory decline, and results from cognitive exams. 11,033 participants developed dementia over the course of the study, allowing the team to look for links between beverage choices and dementia risk.
Moderate Intake Shows Consistent Benefits
According to the study, people who drank more caffeinated coffee had an 18% lower risk of getting dementia compared to those who rarely or never drank it. They also claimed to have fewer memory problems and scored better on some cognitive tests.
People who drank about two to three cups of caffeinated coffee per day or one to two cups of caffeinated tea showed the most consistent benefits. Higher levels of caffeine intake also showed similar benefits. This suggests that these benefits are consistent across typical caffeine consumption ranges.
Tea consumption showed a similar pattern, supporting the idea that shared compounds, particularly caffeine, may play a central role in these potential cognitive benefits. Researchers did not observe the same association with reduced dementia risk or improved cognitive function in participants who consumed only decaffeinated coffee.
Caffeine and Cognitive Protection
These findings indicate that caffeine is a potential contributor to the observed beneficial cognitive effects, although other compounds may also contribute. Coffee and tea also contain polyphenols and other bioactive molecules that may help reduce inflammation and oxidative stress, both of which are connected to age-related cognitive decline.
The study identifies a long-term association between caffeinated beverage consumption and indicators of brain health; however, it stops short of establishing a direct cause-and-effect relationship.
“While our results are encouraging, it’s important to remember that the effect size is small and there are lots of important ways to protect cognitive function as we age,” said senior author Daniel Wang. “Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle.”
Benefits Extend Across Genetic Risk
The researchers also examined whether a genetic predisposition to dementia would impact these results. The link between caffeine intake and lower dementia risk appeared consistent across both high- and low-risk predisposition groups.
“We also compared people with different genetic predispositions to developing dementia and saw the same results,” said lead author Yu Zhang, suggesting that caffeine’s potential benefits may operate independently of inherited risk factors.
Challenges of Prevention
While this study adds to evidence that caffeine may influence dementia risk, it also highlights important limitations. Preventing dementia remains a major challenge, since current treatments only offer limited benefit after symptoms appear. Researchers are increasingly focusing on lifestyle factors such as diet, exercise, and cardiovascular health.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds a Master of Business Administration, a Bachelor of Science in Business Administration, and a Data Analytics certification. His work combines analytical training with a focus on emerging science, aerospace, and astronomical research.