Coffee and tea protect against stroke and dementia


Drinking coffee or tea is associated with reduced risk for stroke and dementia, with the biggest benefit associated with consuming both beverages, new research suggests.

Investigators found that individuals who drank 2 to 3 cups of coffee and 2 to 3 cups of tea per day had a 30% decrease in incidence of stroke and a 28% lower risk for dementia vs those who did not.

The study was published online in PLOS Medicine.

Whereas earlier studies have shown significant health benefits from moderate coffee and tea intake separately, few have examined the effect of drinking both.

Researchers enrolled 365,682 participants from the UK Biobank for the analysis of coffee and tea consumption and stroke and dementia risk and 13,352 participants for the analysis of poststroke dementia.

During a median follow-up of 11.4 years, 2.8% of participants experienced a stroke and 1.4% developed dementia.

After adjusting for confounders, stroke risk was 10% lower in those who drank a half-cup to a cup of coffee per day (P < .001) and 8% lower in those who had more than two cups a day (P = .009). Tea drinkers who had more than two cups a day saw a 16% reduction in stroke (P < .001).

Those who drank both coffee and tea during the day saw the greatest benefit. Drinking 2-3 cups of coffee and 2-3 cups of tea lowered stroke risk by 32% (P < .001) and dementia risk by 28% (P = .002).

Drinking both beverages offered significantly greater benefits than drinking just coffee or tea alone, with an 11% lower risk for stroke (P < .001), an 8% lower risk for dementia (P = .001), and 18% lower risk for vascular dementia (P = .001).

Among those participants who experienced a stroke during the follow-up period, drinking 2-3 cups of coffee was associated with 20% lower risk for poststroke dementia (P = .044), and for those who drank both coffee and tea (0.5-1 cups of coffee and 2-3 cups of tea per day) the risk for poststroke dementia was lowered by 50% (P =.006).

There was no significant association between coffee and tea consumption and risk for hemorrhagic stroke or Alzheimer's disease.