Drinking two to three cups of caffeinated coffee daily was linked to a lower risk of dementia.
The findings come from a long-term study of more than 130,000 people.
Decaffeinated coffee did not show the same association with brain health.
If your day doesn’t really start until that first cup of coffee, there may be some encouraging news.
A large new study suggests that moderate coffee consumption — specifically about two to three cups a day — may be linked to a lower risk of developing dementia later in life.
The research adds to a growing body of evidence exploring how everyday habits might influence long-term brain health. But before you start refilling your mug, it’s important to note: this study shows a connection, not a cause-and-effect relationship.
“When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention — and our unique access to high-quality data through studies that have been going on for more than 40 years allowed us to follow through on that idea,” senior author Daniel Wang said in a news release.
“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. Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle.”
The study
To understand the link between caffeine and cognitive health, researchers analyzed data from more than 131,000 participants across two long-running U.S. studies. Participants regularly reported their coffee and tea intake over time, and researchers tracked who developed dementia, along with changes in memory and thinking skills.
The study followed people for up to 40 years, making it one of the more comprehensive looks at diet and brain health. Over that period, more than 11,000 cases of dementia were documented.
Researchers also accounted for a range of factors that could influence results, including lifestyle habits, overall diet, and health conditions. By adjusting for these variables, they aimed to isolate the potential role of caffeinated beverages in cognitive outcomes.
What the results actually showed
The findings point to a clear pattern: people who consumed more caffeinated coffee tended to have a lower risk of dementia compared to those who drank little or none.
The most noticeable benefit appeared at moderate intake levels — about two to three cups of coffee per day. At that level, participants showed lower rates of dementia and slightly better cognitive performance measures.
“We also compared people with different genetic predispositions to developing dementia and saw the same results — meaning coffee or caffeine is likely equally beneficial for people with high and low genetic risk of developing dementia,” lead author Yu Zhang said in the news release.
Interestingly, the same wasn’t true for decaffeinated coffee, which showed no meaningful association with dementia risk. Tea showed similar trends to caffeinated coffee, suggesting caffeine itself may play a role.
Still, researchers emphasize that the effect was modest, and coffee alone isn’t a guaranteed way to protect your brain. Instead, it may be just one piece of a much larger puzzle when it comes to maintaining cognitive health over time.
If nothing else, this study offers a reassuring takeaway for coffee drinkers: your daily habit might be doing a little more than just helping you power through the morning.