High blood pressure is a common condition that may increase a person’s chances of developing dementia. Research is ongoing to find the best ways to decrease the risk of dementia. A recent study found that among individuals with high blood pressure, consuming one-half to one cup of coffee or four to five cups of tea daily was associated with some of the lowest dementia risk. This study, published in the Scientific Reports, examined the relationship between caffeine consumption and dementia risk using data from over 453,000 participants. The results suggest that people with high blood pressure may be able to decrease their risk of dementia by consuming a certain amount of coffee or tea daily.
Hypertension is a well-established risk factor for dementia, including both vascular dementia and Alzheimer’s disease. High blood pressure can damage the blood vessels in the brain, leading to reduced cerebral perfusion and microvascular damage, contributing to cognitive decline. Chronic hypertension can also lead to the accumulation of small infarcts, white matter lesions, and disruption of the blood-brain barrier, increasing the risk of neurodegenerative processes. The current study aimed to examine how drinking coffee and tea relates to dementia risk, using data from the U.K. Biobank and analyzing 453,913 participants. Results showed that individuals with high blood pressure had a greater risk for dementia, Alzheimer’s disease, and vascular dementia compared to those without high blood pressure, even after adjusting for various factors.
Researchers found a J-shaped relationship between coffee consumption and all-cause dementia among participants with high blood pressure. Participants who drank one-half to one cup of coffee daily had the lowest chances of developing dementia compared to those who drank more or less coffee. There was also a U-shaped association between tea consumption and dementia risk, with participants who drank four to five cups of tea daily having the lowest risk for all-cause dementia. However, no association was found between tea or coffee consumption and dementia risk among participants without high blood pressure. Consuming both coffee and tea in moderation was associated with the lowest chances of developing Alzheimer’s disease and all-cause dementia among participants with high blood pressure.
The type of coffee consumed also appeared to affect dementia risk, with ground coffee associated with the lowest risk for all-cause dementia and vascular dementia compared to decaf coffee. Additionally, a U-shaped association was found between caffeine intake and dementia risk among participants with high blood pressure, indicating that specific levels of caffeine consumption may be associated with decreased risk. It is essential to consume coffee and tea in moderation, as excessive intake can potentially increase the risk of dementia. These findings may have clinical implications for dietary recommendations for patients at risk of dementia, particularly those with hypertension.
However, this study has limitations, including the lack of generalizability to other populations due to the majority of participants being white U.K. citizens. The study cannot establish a causal relationship between dementia and caffeine, and data from the U.K. Biobank may be subject to biases. Residual confounding may also affect the interpretation of the results. More research is needed before implementing changes in clinical practice, but addressing vascular risk factors in dementia prevention, including hypertension management, is crucial. Further understanding of the mechanisms behind the effects of coffee and tea on dementia risk is essential for shaping future guidelines.
