News - Hypertension Week of Jan. 18, 2004/ Vol. 3 No. 03

Study: Regular Tea Consumption Can Reduce Hypertension Risk

People who regularly consume tea may reduce their risk of developing hypertension, according to a study reported in the January issues of the Journal of Nutrition.

Researchers at Kinjo Gakuin University in Japan reached this conclusion after studying the effects of black and green tea on rats with high blood pressure.

The rats were divided into three groups depending on whether they were given tap water, black tea or green tea to drink.

The blood pressures of the rats were recorded continuously for 24 hours. During the daytime, systolic and diastolic blood pressure was significantly lower in the black tea and green tea groups than in the group that received tap water.

Green tea was found to significantly increase the expression of the antioxidant protein catalase, which behaves as a catalyst in the body for the conversion of hydrogen peroxide into water and oxygen. Meanwhile, both green and black tea signicantly decreased the expression of phosphorylated myosin light chain, which also plays a role in hypertension.

"These data demonstrate that both black and green tea polyphenols attenuate blood pressure increases through their antioxidant properties in stroke-prone spontaneously hypertensive rats," the researchers concluded.

"Furthermore, because the amounts of polyphenols used in this experiment correspond to those in approximately one liter of tea, the regular consumption of black and green tea may also provide some protection against hypertension in humans," added the researchers.

Other sources: Journal of Nutrition, 2004 Jan; 134(1): 38-42