Tea Drinkers Reap Blood Pressure Benefits
Drinking a Half-Cup of Tea per Day Cuts Hypertension Risk in Half
Drinking Tea Lowers Blood Pressure continued...
Researchers also collected information about the kind of tea (green, black, or oolong) drunk and how long the participants had been tea drinkers. Green, oolong, and black teas are derived from the same plant. It is the processing of the leaves from the Camellia sinensis that determines the type of tea and the flavonoid content.
The study showed that about 40% of the participants were habitual tea drinkers and had been drinking at least a half-cup of tea per day for one or more years. More than 96% of tea drinkers drank green or oolong tea.
The tea drinkers tended to be younger, mostly men, and had higher educational and socioeconomic status than non-tea drinkers. But they also were more obese, smoked more, drank more alcohol, ate fewer vegetables, and had a higher sodium intake than those who didn't drink tea regularly.
After taking these and other factors associated with heart disease and high blood pressure risk into account, researchers found tea drinkers were much less likely to develop high blood pressure than non-tea drinkers.
Those who drank at least a half-cup of moderate strength green or oolong tea per day for a year had a 46% lower risk of developing hypertension than those who didn't drink tea. Among those who drank more than two and a half cups of tea per day, the risk of high blood pressure was reduced by 65%.
"Nonhabitual tea drinkers were at higher risk of developing hypertension than habitual tea drinkers, and there was a progressive reduction in risk associated with higher levels of tea consumption in daily intake," write the researchers. "However, tea consumption for more than one year was not associated with a further reduction of hypertension risk."
Based on the results of their study, researchers say the minimum tea consumption needed to provide blood pressure-reducing benefits appears to be a half-cup per day of green or oolong tea for at least one year.
They say further long-term studies are needed to confirm these results and better understand the mechanisms behind tea's blood pressure-lowering effects.