23rd November 2021
Coffee and tea may cut dementia and stroke risk
Drinking coffee or tea may be associated with a lower risk of stroke and dementia, according to a new study. Drinking coffee was also associated with a lower risk of post-stroke dementia.
Drinking coffee or tea may be associated with a lower risk of dementia, stroke, and post-stroke dementia, according to a study of healthy individuals aged 50-74 published this month in the open-access journal PLOS Medicine.
Dementia is a general term for symptoms related to decline in brain function and is a global health concern with a high economic and social burden. Strokes are life-threatening events, which cause 10% of deaths globally. Post-stroke dementia is a condition where symptoms of dementia occur after a stroke.
A research team led by Dr Yuan Zhang, from Tianjin Medical University in Tianjin, China, studied data from the UK Biobank. Pictured below, this large-scale and long-term biomedical database and research resource, established in 2006, contains genetic and health information from half a million UK participants.
Zhang's team looked at data for 365,682 people 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, 5,079 participants (1.4%) developed dementia and 10,053 (2.7%) experienced at least one stroke.
People who drank 2-3 cups of coffee or 3-5 cups of tea per day, or a combination of 4-6 cups of coffee and tea had the lowest incidence of dementia or stroke. Individuals who drank 2-3 cups of coffee and 2-3 cups of tea daily had a 28% lower risk of dementia (HR, 0.72, 95% CI, 0.59-0.89; P =0.002) and a 32% lower risk of stroke (HR, 0.68, 95% CI, 0.59-0.79; P <0.001) compared with those who drank neither coffee nor tea. Intake of coffee alone or in combination with tea was also associated with lower risk of post-stroke dementia.
The UK Biobank reflects a relatively healthy sample relative to the general population which could restrict the ability to generalise these associations. Also, relatively few people developed dementia or stroke which can make it difficult to extrapolate rates accurately to larger populations. Finally, while it is possible that coffee and tea consumption might be protective against stroke, dementia and post-stroke dementia, this causality cannot be inferred from the associations.
Overall, the authors conclude: "Our findings suggested that moderate consumption of coffee and tea separately or in combination were associated with lower risk of stroke and dementia."