A cup of tea is good for you. At least three cups a day can reduce the chances of having a stroke by 20 percent. This is the conclusion drawn by Peter Hollman of Human nutrition and food safety institute RIKILT, and outlined in an article in the last issue of The Journal of Nutrition. Hollman's research has made it clear that flavonols are responsible for this effect.
Health impact
That tea is good for the heart and blood vessels has been known for some time. Scientists guessed that this healthy effect could broadly be put down to the role of flavonoids, a big group of substances that includes flavonols. Flavonoids occur in vegetable products and one of their effects is to work as antioxidants. 'Studies on the health impact of flavonoid-rich foods consistently showed a positive effect on the heart and blood vessels', says Hollman. The big question was, though, exactly which flavonoids were behind this effect.'
Big drop
Hollman analysed the relationship between intake of various sorts of flavonoid and the incidence of stroke. His meta-analysis incorporated data from over 100 thousand test subjects from six published studies. He found that specific flavonoids, the flavonols, had an effect on the risk of stroke. 'With an intake of flavonols equivalent to the amount in three cups of tea, you can cut the risk of stroke by 20 percent', says Hollman. 'That is a big drop.'
So should we all increase our tea drinking to get this protection from stroke? Not really, because you can also get your flavonols from fruit and vegetables, chocolate or red wine. Good news for confirmed coffee drinkers who can happily do without tea. /Hans Wolkers
The above article was written by the editorial staff of Resource, the bi-weekly newspaper for Wageningen University and Research centre. For more information, contact the press and science information officer of Wageningen UR, e-mail: pers.communicatie@wur.nl or the editorial staff of Resource, e-mail: resource@wur.nl. See the archived articles at resource.wur.nl