Coffee and tea lovers have reason to celebrate. A comprehensive long-term study evaluating dietary intake and cognitive health has revealed that consuming moderate amounts of caffeinated beverages daily is significantly associated with a reduced risk of dementia.
Study Details
The research, published in the Journal of the American Medical Association last month, followed over 131,000 participants in the United States who were free of cancer, Parkinson's disease, or dementia at the study's outset. The cohort included more than 86,000 women from the Nurses' Health Study (1980–2023) and over 45,000 men from the Health Professionals Follow-up Study (1983–2023). At baseline, the average age was 46 for women and 54 for men. Researchers collected food frequency questionnaires every two to four years to assess coffee and tea consumption and its link to cognitive health.
Key Findings
Among the participants, more than 11,000 cases of dementia were recorded. However, higher intake of caffeinated coffee was significantly associated with a lower risk of dementia and a lower prevalence of subjective cognitive decline. Additionally, higher coffee consumption correlated with better objective cognitive performance in the Nurses' Health Study. Similar cognitive benefits were observed with higher intake of caffeinated tea. The most significant associations were seen with moderate consumption: approximately 2 to 3 cups per day of caffeinated coffee or 1 to 2 cups per day of tea.
Participants with the highest daily coffee intake had an 18% lower risk of developing dementia compared to those with the lowest intake, according to Reuters. Decaffeinated coffee showed no association with reduced dementia risk or improved cognitive performance.
Expert Insights
Yu Zhang of the Harvard T.H. Chan School of Public Health, a lead author, cautioned that the study does not prove caffeine directly lowers dementia risk. "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. He added, "Don't think of coffee or tea as a magic shield. I'd say maintaining a healthy lifestyle, getting regular exercise, having a balanced diet, and getting good sleep are all important for better brain health."
Dr. Kellyann Niotis, a preventive neurologist not involved in the study, noted the challenge of disentangling the effects of coffee from other compounds. "It's definitely possible that these other compounds are interacting with each other, or synergistically with the caffeine itself, to exert some benefit," she told NBC News.
Broader Context
Research indicates that physical and mental activities may help reduce dementia risk, along with diet. A 2023 study in Neurology linked processed red meat consumption to higher dementia risk. Dr. Andy Liu, associate professor of neurology at Duke University School of Medicine, emphasized the importance of a healthy diet combined with exercise for cognitive health. He often recommends the Mediterranean diet to patients with Alzheimer's or cognitive issues. Liu also stressed the importance of early consultation with a doctor if cognitive changes are noticed: "Seeing us earlier is very beneficial. Even if we don't see anything, we tell them to come back and we'll continue to monitor them, which is much safer."
