Drinking 4-6 cups of coffee or tea is linked to a lower risk of stroke and dementia. The corresponding study was published in PLOS Medicine by researchers from Yale University in the US and Tianjin Medical University in China.
Stroke is a leading cause of serious long-term disability and death worldwide- causing around 10% of deaths globally. Meanwhile, dementia, which is an umbrella term for various conditions involving cognitive decline, is also a leading cause of disability and is the seventh leading cause of death worldwide.
In the present study, researchers sought to see whether consumption of coffee and tea affects the incidence of both stroke and dementia. To do so, they analyzed data from 365, 682 people aged 50- 74 years old from the UK Biobank recruited in 2006-2010 and followed until 2020. Participants recorded how much coffee and tea they drank per day at the start of the study.
The researchers then followed their health outcomes over the years to see who developed dementia or stroke. At a median of 11.4 years follow-up, they found that 5,079 participants had developed dementia, and 10,053 had a stroke.
They also found that those 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, were least likely to develop stroke or dementia. They also found that those who drank 2-3 cups of coffee or tea daily were 32% less likely to develop a stroke, and 28% less likely to develop dementia compared to those who drank neither beverage.
The researchers note that there are some limitations to their research. As coffee and tea consumption was self-reported at the beginning of the study, it may not reflect consumption patterns later on. They also say that while they accounted for factors including sex, age, ethnicity, income, and alcohol consumption, it is possible that they missed some important confounders that may have impacted their results.
Nevertheless, the researchers say that their findings suggest that moderate consumption of coffee or tea is linked to a lower risk of both stroke and dementia.