The study led by Susanna C Larsson from Division of Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet in Stockholm, Sweden and colleagues shows black tea drinkers were 21 percent less likely to experience stroke, compared with those who did not drink black tea.
The study did not find the association between black tea drinking and risk of stroke is a dose-response relation.
The study was based on data from 74,961 Swedish men and women who were free of cardiovascular disease at baseline in 1997 who had been followed up for an average of 10.2 years until Dec 2008.
Identified during the study were 4089 cases of first stroke including 3159 cases of cerebral infarction, 435 cases of intracerebral hemorrhage, 148 cases of subarachnoid hemorrhage, and 347 cases of unspecified strokes.
After adjustment for other potential risk factors, high tea consumption was correlated with a significantly lower risk of total stroke, but the correlation is not dose-responsive.
Specifically, compared with no tea consumption, drinking four or more cups of tea per day was associated with 21 percent reduced risk of stroke or 20% reduced risk for cerebral infarction and 32 percent reduced risk for hemorrhagic stroke.
The researchers concluded "These findings suggest that daily consumption of four or more cups of black tea is inversely associated with risk of stroke."
The study did not prove that drinking tea is the cause for the reduction in the risk of stroke in tea drinkers.
It is possible that other lifestyle parameters may be responsible for the risk reduction. For instance, tea drinking people may overall live a healthier lifestyle than other people.
