Green Tea May Help Lower Heart Risk

(July 3, 2008) - After a stressful day, a nice cup of green tea may be just what the doctor orders for your heart. More evidence for the beneficial effect of green tea on risk factors for heart disease (Read about "Coronary Heart Disease") has emerged in a new study reported in the latest issue of European Journal of Cardiovascular Prevention and Rehabilitation. The study found that the consumption of green tea rapidly improves the function of (endothelial) cells lining the circulatory system; endothelial dysfunction is a key event in the progression of atherosclerosis. (Read about "Arteriosclerosis & Atherosclerosis")

The study involved the diameter measurement (dilatation) of the brachial artery of healthy volunteers on three separate occasions - after taking green tea, caffeine, and hot water (for a placebo effect). The measurements were taken at 30, 90 and 120 minutes after consumption. Dilatation of the brachial artery as a result of increased blood flow is related to endothelial function and is known to be an independent predictor of cardiovascular risk. (Read about "The Heart & Cardiovascular System")

Results showed that endothelium-dependent brachial artery dilatation increased significantly after drinking green tea, with a peak increase of 3.9 per cent 30 minutes after consumption. The effect of caffeine consumption (or hot water) was not significant.

While black tea has been associated with improved short and long-term endothelial performance, this is the first time that green tea has been shown to have a short-term beneficial effect on the large arteries. Another study has already shown that green tea reverses endothelial dysfunction in smokers.