Moderate caffeine consumption may offer significant health benefits, according to two new studies. Research suggests a link between higher intake of coffee, tea, and caffeine and a reduced risk of both dementia and atrial fibrillation.
A study published in JAMA Network found that increased consumption of coffee, tea, and caffeine was associated with a lower risk of developing dementia. Researchers also observed associations between caffeine intake and a lower prevalence of subjective cognitive decline, as well as slight improvements in cognitive function.
“Even after adjusting for risk factors related to Alzheimer’s and dementia, researchers found that caffeine consumption was associated with a reduced risk of developing dementia, as well as a reduction in the risk of cognitive decline,” said Professor Anne-Julie Tessier, a specialist in nutrition and health longevity at the University of Montreal’s Department of Nutrition. This finding is particularly relevant as dementia rates continue to rise globally, impacting millions of individuals and families.
The study authors noted that the strongest associations were observed with moderate consumption levels – around two to three cups of coffee or tea per day – with no additional benefits seen at higher intakes. This is “biologically plausible,” they explain, as the absorption, transport, metabolism, and storage of caffeine and other bioactive compounds in coffee and tea have physiological limits. “excessive caffeine consumption can disrupt sleep or increase anxiety, potentially negating any neuroprotective effects.”
Reducing Neuroinflammation
The observed associations remained independent of genetic predisposition and major risk factors for dementia and cognitive decline, the study authors clarified.
Researchers explained that caffeine may reduce pro-inflammatory cytokines in the brain and lessen neuroinflammation, key factors in cognitive decline and the development of Alzheimer’s disease. Beyond caffeine itself, coffee and tea “contain bioactive compounds… that offer antioxidant and vascular benefits by reducing oxidative stress and improving cerebrovascular function.”
“Chlorogenic acid, the main polyphenol in coffee, could be protective for the brain,” Professor Tessier added. “There’s also trigonelline, which is involved in glucose metabolism. We shouldn’t forget the minerals found in coffee either. The hypothesis here is that all these compounds could reduce inflammation and stress in the brain. We also believe that regular consumption helps the brain clear toxic proteins responsible for diseases like Alzheimer’s.”
The authors also suggest that caffeine’s ability to improve insulin sensitivity and reduce the risk of type 2 diabetes – a major risk factor for dementia – contributes to its protective effect on cognitive health.
certain components of tea may offer extra benefits by promoting relaxation and neuroprotection, they said.
“We see a potential benefit, and we also see that it’s safe,” said Professor Tessier. “But the key message here is really to stay in moderation.”
Atrial Fibrillation
Atrial fibrillation is the most common type of heart arrhythmia. Surprisingly, a study last fall found that drinking just one cup of coffee per day may reduce the risk of an episode by 39% in patients with the condition, compared to those who avoid caffeinated beverages.
Specifically, during the six-month study period, 47% of participants who drank one cup of coffee daily reported episodes of atrial fibrillation lasting more than 30 seconds, compared to 64% of patients in the no-caffeine group.
“A tolerance develops when you drink coffee,” Professor Tessier explained. “And there are certain benefits found in coffee, bioactive compounds that have antioxidant properties that could play a role and have some benefits for heart health.”
Researchers noted that all study participants were regular caffeine consumers. They suggest it would be interesting to examine the impact of caffeine on patients with atrial fibrillation who consume little to none.
As study participants limited themselves to one cup per day, the researchers clarified that their findings may not apply to patients who consume more or who drink energy drinks containing caffeine.
In light of these findings, the authors suggest “it is reasonable for healthcare professionals to allow their patients with atrial fibrillation to consider consuming naturally caffeinated substances they enjoy, such as tea and coffee.”
Still, they caution that “some people may still find that caffeine… triggers or worsens their atrial fibrillation.”
