Coffee and Tea May Protect Against Stroke

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High consumption of coffee or tea every day appears to protect malesmokers against at least 1 type of stroke, a new study suggests.

This large, prospective, observational study showed that Finnishsmokers who consumed 8 or more cups of coffee per day had a 23%lowered risk for cerebral infarction, whereas those who drank 2 ormore cups of black tea daily had a 21% lowered risk for this typeof stroke vs those who drank little or none of these beverages. Theassociations were independent of risk factors such as a history ofcoronary heart disease.

Their report is published in the June 2008 issue of Stroke.

Antioxidant Health Benefits

Both coffee and tea are widely consumed caffeinated beverages, thestudy authors write, and both are known to have antioxidant healthbenefits. For example, observational research suggests that coffeedrinking is inversely associated with inflammation and endothelialdysfunction and that it may improve insulin sensitivity and reducethe risk for type 2 diabetes. As for tea, it contains high amountsof polyphenols, which prevent oxidation of low-density lipoproteincholesterol and may reduce platelet activation and plasmaC-reactive protein levels, a marker of inflammation.

Some of these health benefits may extend to prevention of cerebralinfarction, said the study authors. "Beneficial effects ofconsumption of coffee and tea with regard to risk of cerebralinfarction are biologically plausible because coffee and teacontain phenolic compounds with antioxidant properties that mayprevent atherosclerosis," they write.

However, although the relationship between consuming caffeinatedbeverages and the risk for coronary heart disease has been studiedextensively, this current study is among the few to examine theassociation with stroke risk.

Subjects for this study were participants of the Alpha-TocopherolBeta-Carotene Cancer Prevention Study, a randomized, double-blind,placebo-controlled primary prevention trial originally designed todetermine whether alpha-tocopherol, beta-carotene, or both couldreduce cancer incidence in male smokers. The cohort consisted of29,133 Finnish men aged 50 to 69 years who smoked at least 5cigarettes per day and had no history of stroke. From 1985 to 1988,these men were recruited into the trial, which ended in 1993.

At baseline, participants completed questionnaires gatheringgeneral background characteristics, including medical, smoking, andphysical activity histories. Investigators measured height, weight,and blood pressure, calculated body mass index, and obtained levelsof serum total cholesterol and high-density lipoproteincholesterol.

Also at baseline, the researchers used validated food frequencyquestionnaires to assess consumption of coffee and black tea forthe previous year. This information was provided by 26,556 of therandomized participants. At 2 to 5 years after randomization, theresearchers asked the men how they usually prepared their coffee:filtered, boiled, or instant. This information was available for20,427 of the participants. Most used the filter (14,513 [71.1%])or boiling (4232 [20.7%]) method.

Calculating Caffeine Content

To calculate total caffeine consumption, researchers added thecaffeine content of coffee and tea and multiplied it by the amountof consumption. For caffeine content, they used 80 mg per 100 mL ofcoffee and 26 mg per 100 mL of tea.

Approximately 2.5% of the study sample reported never drinkingcoffee, and approximately 64% did not drink tea. The mean dailycoffee consumption among drinkers was 5.7 cups.

Men with higher coffee consumption were slightly younger, smokedmore, had lower systolic and diastolic blood pressures, were lesslikely to have a history of diabetes or coronary heart disease,were more likely to be physically active, and consumed less alcoholand tea than men with low coffee consumption.

Compared with men who did not consume tea, those who did smokedslightly less, were somewhat more likely to be physically active,and consumed more alcohol but less coffee.

In their analysis, the researchers included strokes occurring fromthe time of randomization to December 31, 2004. During a meanfollow-up of 13.6 years, there were 2702 cerebral infarctions, 383intracerebral hemorrhages, 196 subarachnoid hemorrhages, and 84unspecified strokes.

No Association With Other Stroke Types

After adjustment for age and cardiovascular risk factors, bothcoffee and tea consumption were statistically significantlyinversely associated with the risk for cerebral infarction but notto other types of stroke.

Table. Multivariate Risk for Cerebral Infarction for Highest vsLowest Category of Consumption of Coffee and TeaBeverage RelativeRisk