Researchers find that moderate daily intake of coffee and tea is associated with reduced risk of all-cause and 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 individuals with hypertension: a prospective cohort study. Image Credit: Oksana Karuna/Shutterstock.com
In a recent study published in the Scientific Reports, a group of researchers investigated the association between coffee and tea consumption and the risk of developing dementia ( a decline in mental ability affecting daily life) in individuals with hypertension, using data from 453,913 participants in the United Kingdom (UK) Biobank.
Background
Hypertension affects a third of adults worldwide and is linked to increased dementia risk, particularly Alzheimer’s (a brain disorder causing memory loss and cognitive decline). Controlling hypertension could reduce dementia cases by 40%.
Coffee and tea, containing caffeine and chlorogenic acid, may help prevent dementia through neuroprotection and reducing inflammation. However, more research is needed to confirm the effects of these beverages on dementia risk in hypertensive individuals.
About the study
The UK Biobank study is a large population-based investigation that recruited over 500,000 participants aged 39-74 from 2006 to 2010 across Wales, England, and Scotland. Participants underwent physical examinations and completed questionnaires, with their health outcomes continuously monitored through electronic records from primary care, hospitalization, and death registries.
The UK Biobank has collected extensive genetic and health data to explore lifestyle and genetic influences on diseases in middle-aged and older adults. All participants provided informed consent, and the study adheres to the ethical principles of the Helsinki Declaration, with approval from the North West Multi-Centre Research Ethics Committee.
Of the 502,370 participants initially recruited, individuals were excluded for missing baseline data, lack of blood pressure measurements, secondary hypertension, missing coffee and tea consumption information, or a baseline diagnosis of dementia. This resulted in a final cohort of 453,913 participants, 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 through a food frequency questionnaire, while dementia diagnoses were obtained from primary care and hospitalization records.
Cox proportional risk regression models were used to analyze the relationship between coffee, tea, and caffeine intake and dementia risk in hypertensive and non-hypertensive individuals.
Study results
The study included 453,913 participants, of which 54.62% had hypertension. The average age was 72.39 years, with 54.33% being female and 94.13% identifying as white. Over an average follow-up of 15.12 years, those with hypertension had a higher incidence of all-cause dementia, Alzheimer’s disease, and vascular dementia compared to those 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, sex, ethnicity, education, occupation, smoking status, diet, body mass index (BMI), alcohol consumption, physical activity, family history of dementia, social relationships, and other 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.
Regarding 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 relationship between coffee intake and the risk of Alzheimer's or vascular dementia in hypertensive individuals, nor was there a significant association between coffee consumption and dementia risk in the non-hypertensive population.
Tea consumption was linked to a lower risk of all-cause dementia in hypertensive individuals, particularly among those who consumed four to five cups per day. There was no association between tea intake and dementia risk in non-hypertensive participants.
Additionally, hypertensive individuals who consumed both coffee and tea showed a reduced risk of all-cause dementia and Alzheimer’s disease, particularly those who drank moderate amounts of both beverages.
Ground coffee was associated with a lower risk of all-cause and vascular dementia in both hypertensive and non-hypertensive populations, compared to decaffeinated coffee. The study found no significant relationship between the temperature of hot drinks and dementia risk.
Caffeine intake was also linked to a reduced risk of all-cause 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 or vascular dementia in non-hypertensive individuals.
Conclusions
To summarize, in this study, individuals with hypertension had a higher risk of developing dementia compared to those without hypertension. The consumption of coffee and tea was associated with dementia risk in the overall population, with the lowest risk observed among hypertensive individuals who drank 0.5-1 cup of coffee or 4-5 cups of tea daily.
This significant association between coffee and tea consumption and the risk of all-cause and vascular dementia was more evident in hypertensive individuals than in those without hypertension.
Additionally, ground coffee consumption was linked to the lowest risk of all-cause and vascular dementia, with no association between hot drink temperature and dementia risk.
Study links historical education policies to better cognitive outcomes later in life