By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

In many Western countries, the mortality from stroke has been declining in the last few years. Several studies have suggested that one reason for this may be an increase in the consumption of fruits and vegetables, which contain antioxidants and other beneficial chemicals. Among these chemicals are flavonoids, which are non-nutritive compounds with antioxidant properties, which occur naturally in plant foods, particularly tealeaves and fruits.

A recently published study of 552 Dutch men examined the relationship between intake of various nutrients and stroke over a 15-year period. Forty-two men had a stroke, and when their characteristics at the start of the study were compared with those of the men who didn't have a stroke, it was found that they had higher blood pressure (no surprise here), ate less fish and also less flavonoids. The main source of flavonoids was from drinking tea, and men who drank more than four cups a day had a two-thirds lower risk of stroke than men who drank less than two to three cups. The other source of flavonoids was fruit. Interestingly, no association was found for some of the other antioxidants such as beta-carotene, vitamin C and vitamin E.

Doctor's comments

This is the first study to show a protective effect of flavonoids against stroke, although the same group of researchers reported earlier that they can protect against heart attacks. One possible explanation for the lack of any connection between the intake of other antioxidants (beta carotene, vitamins C and E) and strokes may be that relatively few of the men in the study were taking vitamin supplements, and the beneficial effects of these antioxidants may only be seen with larger doses than are normally present in food. Drinking tea is probably a good thing to do, but these findings don't necessarily apply to herbal teas.

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