High blood pressure is a common condition that may increase a person’s chances of developing dementia. Research is ongoing about the best ways to decrease the risk of dementia, with a recent study finding that among people 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 Scientific Reports, used data from over 453,000 participants and observed that people with high blood pressure may be able to decrease their risk of developing dementia by consuming a certain amount of coffee or tea. While more data is required, the results highlight another potential protective action step that may benefit people with high blood pressure.
Hypertension contributes to increased dementia risk because it can cause damage to blood vessels in the brain, leading to reduced cerebral perfusion and microvascular damage. Over time, chronic hypertension may lead to the accumulation of small infarcts, white matter lesions, and disruption of the blood-brain barrier, all of which increase the risk of neurodegenerative processes. A study using data from the U.K. Biobank found that individuals with high blood pressure had a greater risk for all-cause dementia, Alzheimer’s disease, and vascular dementia compared to those without high blood pressure. However, the researchers also identified a potential link between drinking coffee and tea and reduced dementia risk among participants with high blood pressure, highlighting the importance of addressing vascular risk factors in dementia prevention.
The study found a J-shaped relationship between coffee consumption and all-cause dementia among participants with high blood pressure, with the lowest risk observed in those who consumed one-half to one cup of coffee daily. Additionally, a U-shaped association was identified between tea consumption and all-cause dementia among participants with high blood pressure, with the lowest risk observed in those who drank four to five cups of tea daily. When examining tea and coffee consumption together, participants with high blood pressure who had four to five cups of coffee and six or more cups of tea a day had the lowest chances of developing Alzheimer’s disease and all-cause dementia, compared to those who did not drink tea but still consumed six or more cups of coffee daily.
The researchers also found that the type of coffee consumed appeared to have an effect, with ground coffee associated with the lowest risk for all-cause dementia and vascular dementia among all participants compared to decaf coffee. Additionally, a U-shaped association was observed between caffeine intake and risk for vascular and all-cause dementia among participants with high blood pressure, with excessive caffeine intake linked to increased risk of dementia. While a low-moderate amount of coffee intake decreased the risk of dementia, having six or more cups a day appeared to increase the risk, likely due to excessive caffeine intake. Moderation in coffee and tea consumption was emphasized as a key factor in reducing the risk of dementia in individuals with hypertension.
The study, however, has limitations, including the fact that the U.K. Biobank does not necessarily reflect the general population, as most participants are white U.K. citizens who may be more health-conscious. The study also cannot establish a causal relationship between dementia and caffeine consumption, and there may be information bias in self-reported baseline intake of coffee and tea. Despite these limitations, the study highlights the potential benefits of coffee and tea consumption in reducing the risk of dementia among individuals with high blood pressure. Further research is needed to replicate these findings and understand the mechanisms behind the protective effects of coffee and tea in dementia prevention.
