Researchers find that moderate daily intake of coffee and tea is associated with a reduced risk of all-cause vascular dementia in people with hypertension, based on data from 453,913 participants in the UK Biobank.
Study: Association between coffee and tea consumption and the risk of dementia in persons with hypertension: a prospective cohort study. Image credits: Oksana Karuna/Shutterstock.com
From a recent study published in the Scientific reports, a group of researchers examined the link between coffee and tea consumption and the risk of developing dementia (a decline in mental ability that affects daily life) in individuals with hypertension, using data from 453,913 participants in the United Kingdom Biobank Kingdom (UK).
Background
Hypertension affects a third of adults worldwide and is linked to an increased risk of dementia, especially Alzheimer’s disease (a brain disorder that causes memory loss and cognitive decline). Controlling high blood pressure could reduce the incidence of dementia by 40%.
Coffee and tea, which contain caffeine and chlorogenic acid, may help prevent dementia by neuroprotection and reducing inflammation. However, more research is needed to confirm the effects of these drinks on the risk of dementia in hypertensive individuals.
About the study
The UK Biobank study is a large population-based study that recruited over 500,000 participants aged 39-74 years in Wales, England and Scotland between 2006 and 2010. Participants underwent physical examinations and completed questionnaires, with their health outcomes continuously monitored via electronic records from primary care, hospital admissions and death registries.
The UK Biobank has collected extensive genetic and health data to investigate lifestyle and genetic influences on disease in middle-aged and older adults. All participants gave informed consent and the study complies with the ethical principles of the Declaration of Helsinki, with approval from the North West Multi-Centre Research Ethics Committee.
Of the 502,370 initially recruited participants, individuals were excluded due to missing baseline data, lack of blood pressure measurements, secondary hypertension, missing information on coffee and tea consumption, or a basic diagnosis of dementia. This resulted in a final cohort of 453,913 participants, who were followed for an average of 15.12 years until April 2024.
Hypertension status was determined using self-reported data, hospital records, and blood pressure measurements. Coffee and tea consumption was assessed using a food frequency questionnaire, while dementia diagnoses were obtained from primary care and hospital admission records.
Cox proportional hazard regression models were used to analyze the relationship between coffee, tea, and caffeine intake and the risk of dementia in hypertensive and nonhypertensive individuals.
Study results
The study included 453,913 participants, 54.62% of whom had hypertension. The mean age was 72.39 years, with 54.33% female and 94.13% identifying as white. Over a mean follow-up of 15.12 years, people with hypertension had a higher incidence of all-cause dementia, Alzheimer’s disease, and vascular dementia compared with people without hypertension.
Hypertensive participants also had a shorter median survival time. Significant differences were noted between hypertensive and non-hypertensive individuals in terms of age, gender, ethnicity, education, occupation, smoking status, diet, body mass index (BMI), alcohol consumption, physical activity, family history of dementia, social relationships, and others health factors. After adjusting for these variables, individuals with hypertension were found to have a higher risk of developing all-cause dementia, Alzheimer’s disease and vascular dementia.
In terms of coffee consumption, those with hypertension who drank 0.5 to 1 cup of coffee daily had the lowest risk of all-cause dementia.
However, there was no significant association between coffee intake and the risk of Alzheimer’s disease or vascular dementia in hypertensive individuals, nor was there a significant association between coffee consumption and the risk of dementia in the non-hypertensive population.
Tea consumption was associated with a lower risk of all-cause dementia in hypertensive individuals, especially among those who consumed four to five cups per day. There was no association between tea intake and the risk of dementia in non-hypertensive participants.
In addition, hypertensive individuals who consumed both coffee and tea showed a reduced risk of all-cause dementia and Alzheimer’s disease, especially those who drank moderate amounts of both beverages.
Ground coffee was associated with a lower risk of vascular dementia from any cause in both hypertensive and non-hypertensive populations, compared with decaffeinated coffee. The study found no significant relationship between the temperature of hot drinks and the risk of dementia.
Caffeine intake was also associated with a reduced risk of all-cause dementia and vascular dementia in hypertensive participants, with those consuming moderate amounts of caffeine showing the lowest risk.
In contrast, no significant associations were observed between caffeine intake and the risk of Alzheimer’s disease or vascular dementia in non-hypertensive individuals.
Conclusions
In summary, in this study, individuals with hypertension had a higher risk of developing dementia compared to those without hypertension. Coffee and tea consumption was associated with the risk of dementia in the overall population, with the lowest risk observed in individuals with high blood pressure who drank 0.5 to 1 cup of coffee or 4 to 5 cups of tea daily.
This significant association between coffee and tea consumption and the risk of all-cause vascular dementia was more pronounced in hypertensive individuals than in those without hypertension.
Furthermore, ground coffee consumption was associated with the lowest risk of vascular dementia regardless of cause, with no association between the temperature of hot drinks and dementia risk.