In a prospective cohort study, people who drank two to three cups of coffee or three to five cups of tea per day, or a combination of four to six cups of coffee and tea, had the lowest incidence of stroke or dementia

Stroke MRI scan of cerebral brain vessels

Drinking coffee or tea may be associated with a lower risk of stroke and dementia, according to a large-scale observational study of healthy individuals recruited from the UK Biobank.

The prospective cohort study, published in PLoS Medicine, found that drinking coffee was also associated with a lower risk of post-stroke dementia.

Previous studies have revealed the involvement of tea and coffee consumption in the development of stroke and dementia. However, little is known about the association between the combination of coffee and tea and the risk of stroke, dementia, and post-stroke dementia. Therefore, this study aimed to investigate the associations of coffee and tea separately and in combination with the risk of developing stroke and dementia.

The researchers studied 365,682 participants aged 50–74 years from the UK Biobank, who were recruited between 2006 and 2010, and followed them until 2020. At the outset, participants self-reported their coffee and tea intake. Over the study period, 5079 participants developed dementia and 10,053 experienced at least one stroke.

People who drank two to three cups of coffee or three to five cups of tea per day, or a combination of four to six cups of coffee and tea, had the lowest incidence of stroke or dementia.

Individuals who drank two to three cups of coffee or tea daily had a 32% lower risk of stroke (HR, 0.68; 95% CI 0.59–0.79; p<0.001) and a 28% lower risk of dementia (HR, 0.72; 95% CI 0.59–0.89; p=0.002) compared with those who drank neither coffee nor tea.

Moreover, the combination of coffee and tea consumption was associated with a lower risk of ischaemic stroke and vascular dementia. Additionally, the combination of tea and coffee was associated with a lower risk of post-stroke dementia, with the lowest risk at a daily consumption level of three to six cups of coffee and tea (HR, 0.52; 95% CI 0.32–0.83; p=0.007).

The study’s main limitations were that coffee and tea intake was self-reported at baseline and may not reflect long-term consumption patterns, unmeasured confounders in observational studies may result in biased effect estimates, and UK Biobank participants are not representative of the whole UK population.

The study authors thus cautioned that, while it is possible that coffee and tea consumption may be protective against stroke, dementia, and post-stroke dementia, this causality cannot be inferred from the associations.

This article originally appeared on Univadis, part of the Medscape Professional Network.

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Lead image: DedMityay/stock.adobe.com

Image 1: DedMityay/stock.adobe.com