Coffee is one of the most consumed beverages in the world. Beyond its well-known stimulating effects, it may also play a role in brain health. A large study conducted by researchers from Harvard, MIT, and Brigham and Women's University suggests that drinking two to three cups of caffeinated coffee per day is associated with a lower risk of dementia.
A study conducted on more than 130,000 people
To better understand the impact of coffee on brain aging, researchers analyzed data from more than 130,000 participants followed for approximately 43 years. The results were published in the scientific journal JAMA.
During this period, scientists observed the participants' coffee and tea consumption habits, as well as their cognitive health over time. The analyses showed that people who regularly consumed caffeinated coffee had a lower risk of developing dementia compared to those who drank little or none.
A reduced risk of dementia of approximately 18%
According to the study's results, participants who drank the most coffee had approximately an 18% lower risk of developing dementia during the follow-up period. Researchers also observed that these participants performed better on average on certain cognitive tests, including those assessing memory and information processing speed. The benefits appeared particularly pronounced in individuals who consumed about two to three cups of coffee per day.
The possible role of caffeine
The study's results suggest that caffeine may play a role in this potential protective effect. Indeed, the researchers did not observe the same link between decaffeinated coffee consumption and the risk of dementia. This difference suggests that certain compounds present in caffeinated coffee, particularly caffeine, may influence brain health.
Caffeine is known to act on the central nervous system and to block certain receptors involved in brain aging processes. However, researchers point out that the exact mechanisms remain to be clarified.
Similar effects observed with tea
The study also examined tea consumption. Researchers found a similar association between moderate tea consumption and a lower risk of dementia. Specifically, the results indicate that people who drank about one to two cups of tea per day also experienced a slightly slower cognitive decline than those who did not. These observations suggest that certain substances present in these beverages, such as caffeine or some antioxidants, may help protect brain function.
An association, not proof of causation
Despite these encouraging results, the researchers emphasize that their study shows a statistical association, not a cause-and-effect relationship. Other factors could also influence the observed results. For example, people who consume coffee may have different lifestyle habits, such as a particular diet, a higher level of physical activity, or better access to healthcare. The scientists therefore reiterate that coffee should not be considered a single solution for preventing dementia.
The role of lifestyle in cognitive health
Numerous studies show that brain health depends on several combined factors. A balanced diet, regular physical activity, intellectual stimulation, and management of cardiovascular risk factors all play an important role in preventing cognitive decline.
Moderate coffee consumption could therefore be part of a broader set of habits that are beneficial to brain health. For researchers, these results nevertheless open up interesting avenues for better understanding the links between certain widely consumed beverages and brain aging.
