Coffee and tea lovers, rejoice. A long-term study evaluating dietary intake and cognitive health found that drinking moderate amounts of the caffeinated beverages every day was significantly associated with a lower risk of dementia.
The study, published in the Journal of the American Medical Association last month, followed over 131,000 participants in the U.S. who did not have cancer, Parkinson’s disease or dementia at the start of the study as a baseline.
The study included more than 86,000 female participants in the Nurses’ Health Study from 1980 to 2023, and more than 45,000 male participants in the Health Professionals Follow-up Study from 1983 to 2023. The female participants began the study at an average age of 46, and the average age for the male participants was 54.
To evaluate associations between coffee and tea and cognitive health, researchers collected food frequency questionnaires from the participants every two to four years.
The results showed that there were more than 11,000 cases of dementia among the participants, but that higher caffeinated coffee intake was significantly associated with lower dementia risk and a lower prevalence of subjective cognitive decline. Higher coffee intake was also associated with better objective cognitive performance among participants in the Nurses’ Health Study. A higher intake of caffeinated tea was associated with similar cognitive outcomes.
As for how much coffee and tea made a difference, researchers noted that the most significant association with lower dementia risk and a lower prevalence of cognitive decline was seen with participants who consumed moderate levels of coffee or tea — or “approximately 2 to 3 cups per day of caffeinated coffee or 1 to 2 cups per day of tea.”
Researchers found that people with the highest daily intake of coffee compared to those with the lowest intake were at a 18% lower risk of developing dementia. The results were similar for those who drank caffeinated tea, Reuters reported.
The study found that decaffeinated coffee was not associated with lower dementia risk or better cognitive performance.
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Yu Zhang of the Harvard T.H. Chan School of Public Health, a lead author of the study, cautioned that the research doesn’t prove that caffeine directly lowers your risk of dementia.
“Our study alone can’t prove causality, but to our knowledge, it is the best evidence to date looking at coffee and tea intake and cognitive health, and it is consistent with plausible biology,” Zhang told The Guardian.
“Don’t think of coffee or tea as a magic shield,” Zhang added. “I’d say maintaining a healthy lifestyle, getting regular exercise, having a balanced diet and getting good sleep are all important to get better brain health.”
Dr. Kellyann Niotis, a preventive neurologist who was not involved in the study, told NBC News that it’s important to consider that it’s “really a big challenge to disentangle the effects of coffee as a whole from all of the other compounds that are also in coffee — and tea.”
“It’s definitely possible that these other compounds are interacting with each other, or synergistically with the caffeine itself, to exert some benefit,” she said.
Research has shown that physical and mental activities may play an important role in reducing your risk for dementia, but that it’s also important to consider your diet.
For example, a study published in the journal Neurology last year found that eating processed red meat was linked to a higher chance of developing dementia or experiencing cognitive decline.
Dr. Andy Liu, an associate professor of neurology at the Duke University School of Medicine, previously emphasized to HuffPost that a healthy diet, combined with physical exercise, is beneficial for cognitive health.
He said he tends to recommend the Mediterranean diet to his patients — especially to those with Alzheimer’s disease or cognitive issues.
But overall, Liu said, it’s important to speak to a doctor sooner rather than later if you notice cognitive changes.
“Seeing us earlier is very beneficial,” Liu explained. “Even if we don’t see anything, we tell them to come back and we’ll continue to monitor them, which is much safer. And then we can take action if we do notice changes.”
