- Drinking tea or coffee daily is associated with a lower risk of stroke and dementia.
- The researchers tracked the health of more than 360 000 people.
- Causality can, however, be concluded from the association, and more research is needed.
Coffee and tea are two massively popular drinks, and according to the latest research, they may also have beneficial health effects on your body and brain.
That’s right, a cup of tea or coffee per day is associated with a lower risk for stroke and dementia, suggests a study published in PloS Medicine this month.
The researchers of the current study, from Tianjin Medical University, China, and Yale University, US, looked at 365 000 people aged 50 to 74 years and found that moderate consumption of these beverages may have health benefits.
The paper points out that it is the largest study of its kind to date.
Stroke and dementia stats
Stroke is responsible for 10% of global deaths, according to a 2017 study published in The Lancet. In South Africa, the Heart and Stroke Foundation points out that every day in the country, nearly 240 people will suffer a stroke, and nearly 70 of them will die.
Dementia, a deterioration in brain function, is a huge global health challenge – currently, more than 55 million people worldwide live with the condition. There are nearly 10 million new cases every year and it is currently the seventh leading cause of death, according to the World Health Organization (WHO).
For their study, the researchers followed the 365 000 participants for more than a decade. At the start of the study, participants from the UK self-reported how much coffee and tea they drank.
While tracking the data, the investigators found that over this lengthy period, 5 079 participants developed dementia while 10 053 went on to have at least one stroke.
What they found
According to the findings, participants who had the lowest risk of developing stroke or dementia either drank two to three cups of coffee a day, had three to five cups of tea a day, or had a combination of four to six cups of tea and coffee a day.
Moreover, those who drank two to three cups of tea daily and two to three cups of coffee had a 32% lower risk of stroke, the researchers wrote. These people also had a 28% lower risk of dementia compared with those who did not drink tea or coffee.
If you’re both a coffee and tea lover, there’s additional promising news – drinking coffee in combination with tea was also linked with a lower risk of post-stroke dementia
“Our findings suggest that moderate consumption of coffee and tea separately or in combination was associated with lower risk of stroke and dementia,” the authors wrote.
The team, however, cautioned that their study had some limitations.
These included that the participants involved in the study were also part of the UK Biobank study, which reflects a sample of people who tend to be more health-conscious than the general population – what the study investigators called a “healthy volunteer” selection bias. This means the findings may not be representative of the UK population.
Since tea and coffee intake was self-reported, it may not reflect long-term consumption patterns, which could affect the results, the team added. “Future research is needed to investigate the impact of changes in coffee and tea intake over time on stroke and dementia risk.”
More than 90% of participants reported themselves as white British, so the researchers could not infer an association relevant to people of other ethnicities.
The researchers concluded that while their findings support an association between moderate tea and coffee consumption and risk of stroke and dementia, “whether the provision of such information can improve stroke and dementia outcomes remains to be determined”.
Considering around two billion cups of coffee and about 3.7 billion cups of tea are consumed worldwide every day, it may be worthwhile for scientists to further investigate the current study’s findings.
Dr Rosa Sancho, head of research at Alzheimer’s Research UK, commented about the study in a news release: “For most of us, our risk of dementia depends on the complex interaction of our age, genetics and lifestyle. Understanding which aspects of our lifestyle have the greatest effect on our brain health is key to empowering people to make informed decisions about their lives.”
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