Coffee, tea, and the risk of stroke

Both beverages have antioxidant properties, and coffee may improve insulin sensitivity.

OK, but is there an association between coffee and tea consumption with the risk of stroke?

First, the details.

  • 26,556 male Finnish smokers (aged 50 to 69 years) were followed for about 14 years.
    • All were participants in the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study, originally designed to determine the effect of alpha-tocopherol and/or beta-carotene on cancer risk.
  • Participants had no history of stroke.
  • Coffee and tea consumption at the start of the study was assessed using a questionnaire.
    • Caffeine was standardized at 80 mg/100 mL, and tea at 26 mg100 mL.
  • Information on smoking, physical activity, height, weight, blood pressure, body mass index, and cholesterol levels were recorded.

And, the results.

  • There were 2702 cerebral infarctions (stroke due to blocked blood flow to the brain; aka ischemic stroke), 383 intracerebral hemorrhages, and 196 subarachnoid hemorrhages (bleeding in different areas of the brain).
  • After adjusting for age and heart-related risk factors, drinking more coffee or tea throughout the day lowered the risk of cerebral infarction (but not stroke due to hemorrhage).
  • The risk for men in the highest category of coffee consumption (at least 8 cups/day) was significantly lower than drinking fewer than 2 cups/day.
  • For tea, the risk of cerebral infarction was significantly lower for drinking at least 2 cups/day compared to not drinking tea.

The bottom line?
The authors caution, “As in any observational study, we cannot entirely rule out the possibility that the observed associations were attributable to confounding by other risk factors.”

That said, the ability to follow patients over time rather than have to review old records is a strength of the study. Also, the high number of strokes and extensive information of the cardiovascular history of the participants support the ability to make associations.

What this means for women is not known, and men of different ethnicity might not respond to coffee and tea the same way.

6/28/08 10:13 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.