Tea, coffee could help ward off stroke, dementia

Drinking coffee and tea, separately or in combination, seems to help protect against the risk of stroke or dementia, according to a recent study.

“These findings highlight a potential beneficial relationship between coffee and tea consumption and risk of stroke, dementia, and poststroke dementia, although causality cannot be inferred,” the researchers said. “These findings may be of interest to clinicians involved in the prevention and treatment of stroke, dementia, and poststroke dementia.”

The present prospective cohort included 365,682 participants (mean age 60.4±5.1 years, 45.7 percent men) enrolled in the UK Biobank and followed until 2020. Most frequently, participants reported drinking 0.5–1 cup of coffee and ≥4 cups of tea per day (16.29 percent; n=59,558). On the other hand, 50,015 respondents (13.68 percent) said they consumed 0 cup of coffee and ≥4 cups of tea per day.

Meanwhile, 44,868 participants (12.27 percent) drank 2–3 cups of coffee and 2–3 cups of tea per day. For comparison, the researchers recorded 75,986 (20.8 percent) and 50,009 (13.7 percent) participants who were nondrinkers of coffee and tea, respectively.

Multivariable adjusted Cox models found a significant and robust inverse correlation between tea intake and stroke risk. For instance, drinking 2–3 cups (hazard ratio [HR], 0.84, 95 percent confidence interval [CI], 0.79–0.90; p<0.001) and ≥3 cups (HR, 0.84, 95 percent CI, 0.79–0.90; p<0.001) of tea per day both suppressed stroke risk by 16 percent. [PLoS Med 2021;18:e1003830]

Notably, both coffee and tea intake, when taken separately, likewise reduced the risk of ischaemic stroke, but not haemorrhagic stroke.

When looking at joint effect of coffee and tea intake on stroke risk, the researchers found that drinking 2–3 cups of coffee and tea per day reduced stroke risk by more than 30 percent as compared to no intake (HR, 0.68, 95 percent CI, 0.59–0.79; p<0.001).

Similarly beneficial effects were reported for dementia, in which the joint daily consumption of 0.5–1 cup of coffee and ≥4 cups of tea reduced such risk by 30 percent relative to nondrinkers (HR, 0.70, 95 percent CI, 0.58–0.86; p<0.001). Drinking 2–3 cups of coffee and tea per day had a similar effect (HR, 0.72, 95 percent CI, 0.59–0.89; p=0.002).

Moreover, joint consumption of 0.5–1 cup of coffee and 2–3 cups of tea per day halved the risk of poststroke dementia (OR, 0.50, 95 percent CI, 0.31–0.82; p=0.006), an effect driven mostly by coffee intake (2–3 cups per day vs nondrinkers: HR, 0.80, 95 percent CI, 0.64–0.99; p=0.044). Tea drinking alone did not affect poststroke dementia risk.

“Preventing the risk of stroke and dementia is particularly important. Despite advances in understanding the pathophysiology of stroke and dementia, clinical treatment of stroke and dementia continues to be suboptimal,” the researchers said. “Therefore, identifying the preventable risk factors for stroke and dementia is of high priority.

“From a public health perspective, because regular tea and coffee drinkers comprise such a large proportion of the population and because these beverages tend to be consumed habitually throughout adult life, even small potential health benefits or risks associated with tea and coffee intake may have important public health implications,” they added. “Further clinical trials on lifestyle interventions will be necessary to assess whether the observed associations are causal.”