How many of us can’t seem to get our engines running each morning without first having that cup o’ Joe? The aroma of fresh coffee wafting down the hallway as we make our way to the kitchen and take that first sip induces a true physiological effect, enabling us to start our day, fortified by the caffeine that we seemingly can’t live without. Little did we know that our morning coffee, the Sunday brunch cappuccino, and that hot cup of tea before bedtime may have some true health benefits–they are associated with reduced rates of stroke and dementia as shown by new studies.
Drinking coffee or tea may be associated with a lower risk of stroke and dementia, according to a study of healthy individuals aged 50-74 published in PLOS Medicine. Drinking coffee was also associated with a lower risk of post-stroke dementia.
Strokes are life-threatening events which cause 10 percent of deaths globally. “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. Post-stroke dementia is a condition where symptoms of dementia occur after a stroke.
Yuan Zhang and colleagues from Tianjin Medical University, Tianjin, China studied 365,682 participants 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, 5,079 participants developed dementia and 10,053 experienced at least one stroke.
The UK Biobank reflects a relatively healthy sample relative to the general population which could restrict the ability to generalize 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’s possible that coffee and tea consumption might be protective against stroke, dementia, and post-stroke dementia, this causality cannot be inferred from the associations.
The authors add, “Our findings suggested that moderate consumption of coffee and tea separately or in combination were associated with lower risk of stroke and dementia.”
Researchers from China and the US found that people who drank two to three cups of tea and coffee a day had a lower risk of stroke and vascular dementia.
Participants self-reported their tea and coffee drinking habits at the beginning of the study. Researchers then recorded the numbers of people who went on to have a stroke (2.8%) or develop Alzheimer’s disease or vascular dementia (1.4%).
What did the scientists find?
People who drank two to three cups of coffee with two to three cups of tea per day had around 30% lower risk of stroke and dementia when compared to those who didn’t consume either. This association was found for people who just drank either tea or coffee, as well as those who drank both.
People who had the lowest risk of developing dementia or stroke either:
- Had two to three cups of coffee a day.
- Had three to five cups of tea a day.
- Had a combination of four to six cups of tea and coffee a day.
Researchers in this study found that drinking tea and coffee was linked to a lower risk of having an ischemic stroke (caused by a blocked blood vessel) and vascular dementia, rather than a hemorrhagic stroke (caused by a burst blood vessel) or Alzheimer’s disease.
Dr. Rosa Sancho, Head of Research at Alzheimer’s Research UK, said, “For most of us, our risk of dementia depends on the complex interaction of our age, genetics and lifestyle. We know that stroke increases the risk of developing vascular dementia. 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.
“Studies like this one are not able to pinpoint cause and effect, and while the researchers attempted to control for other factors that could affect a person’s risk of stroke and vascular dementia, no firm conclusions can be made about whether tea or coffee cause this lower risk. Participants only reported tea and coffee consumption at the beginning of the study, and there is no data on long-term habits, so it’s not clear how relevant the findings are to long-term brain health.
“While previous studies have looked at associations between tea and coffee consumption and better brain health, there has been inconsistency in findings. Future research with participants of a range of ages and ethnicities will be needed to fully understand what types of dementia and stroke are associated with tea and coffee drinking. Participants in this study reported themselves to be mainly White British (96%), therefore we cannot infer an association that is relevant to everyone in the UK.”
While it appears that more studies will need to be done to establish the premise of caffeine consumption as an absolute deterrent to the risks associated with strokes and dementia, it seems safe to say we can still enjoy our coffee and tea–as in all things, in moderation–and perhaps even the occasional scone!
Written by Sherri Abergel
- Coffee and tea drinking may be associated with reduced rates of stroke and dementia
- Regularly drinking tea and coffee associated with a lower risk of stroke and dementia
- Coffee and tea consumption may be associated with lower risk of stroke, dementia
- Consumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank