Coffee and Tea Linked With Reduced Rates of Stroke and Dementia – Here’s How Much To Drink

Intake of 4-6 total cups daily was associated with lowest risks.

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 on November 16th, 2021, in the open-access journal PLOS Medicine. Drinking coffee was also associated with a lower risk of post-stroke dementia.

Strokes are life-threatening events that 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.

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 stroke or dementia. Individuals who drank 2-3 cups of coffee and 2-3 cups of 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. 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 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.”

Reference: “Consumption of coffee and tea and risk of developing stroke, dementia, and poststroke dementia: A cohort study in the UK Biobank” by Yuan Zhang, Hongxi Yang, Shu Li, Wei-dong Li and Yaogang Wang, 16 November 2021, PLoS Medicine.
DOI: 10.1371/journal.pmed.1003830

Funding: This study was funded by the National Natural Science Foundation of China (Grant No. 91746205), received by YW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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  • Trired of Hype

    Yet another half-baked statistical “study” proving nothing. Just wait a week and someone will decide that coffee and tea kill you.

      • ken Towe

        Maybe that explains why most politicians do what they do?

      • Greg

        Did you read the article you linked? It says that more than 6 cups of coffee was associated an increase in risk of dementia. This is hardly “the exact opposite” of this article. Taken together, these studies seem to suggest that moderate amounts of coffee/tea may reduce the risk of dementia and/or stroke. Of course, conducting long-term human studies for these types of things is neither feasible nor ethical, so we’ll just have to interpret the results of these studies to the best of our ability, and – of course – make your own decision.

  • Pradeep

    Is this true for decaffeinated coffee/tea as well?

  • Janice Hadlock

    Coffee = anti-stroke? Another example of poor logic in the medical field. People who don’t drink coffee are often more edgy or bubbly to begin with. The buzz of coffee can be unpleasant for people whose personality type is more fired up and dynamic than average. These people might also run “hotter,” have higher blood pressure, higher heart rate, and thus be more predisposed to stroke and other poor health outcomes, regardless of whether or not they drink java. Their dislike for coffee and hot, stimulating tea can be a *reflection* of their heightened metabolic factors. If an person with hyper-intensity of thought and metabolism forces himself to drink coffee for its purported health benefits he/she might actually increase his already excess level of heart stimulation, and make himself more prone to stroke.
    A similar study, years ago, picked up the fact that people with Parkinson’s tend to not drink coffee, and laughably concluded that drinking coffee prevents Parkinson’s disease. I wrote a commentary to the JAMA, that was accepted for publication, back in 2003, pointing out that people with Parkinson’s, even in the decades before the symptoms of Parkinson’s become obvious, tend to have an excessively sympathetic mode-dominant personality. They don’t like coffee because it increases their hair trigger reactions and makes them even more edgy than they already are. They don’t drink coffee because it makes them feel worse. The reason those who drink coffee don’t get Parkinson’s is because they don’t already have the underlying factors that are building up to eventual Parkinson’s disease – factors that make the side effects of coffee unpleasant.
    Dr. J. Hadlock, DAOM, LAc

  • Tim

    Correlation does not equal causation. The article basically states this “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.”

    This is much ado about nothing without further research.