By Jenny Hope
A cup of green tea a day could help keep your heart healthy, a study shows. The drink was found to widen the artery, which runs from the shoulder to the elbow by 4 per cent within 30 minutes - reducing the risk of blood clots. This is a good indicator of improved blood flow around the body, says a report in the European Journal of Cardiovascular Prevention and Rehabilitation.
Dr Nikolaos Alexopoulos and colleagues at the 1st Cardiology Department, Athens Medical School, used ultrasound scanning to measure the performance of the brachial artery - which runs from the shoulder to the elbow, and is a good indicator of blood flow around the body. A team of healthy volunteers were given green tea, caffeine or hot water to drink on three separate occasions. Measurements of the brachial artery were taken at three stages after they drank their beverage.
The researchers found the artery expanded by four per cent 30 minutes after volunteers drank green tea. Caffeine or hot water had no effect. Dilation of the artery shows better functioning of the endothelium, the layer of cells lining blood arteries that stops clots forming. Previous research suggests black tea improves short and long-term endothelial performance, but this is the first time green tea has been shown to have a short-term beneficial effect on the large arteries.
Green tea is traditionally consumed in China and Japan and differs from black tea in that it is not fermented before drying. This fermentation process appears to reduce the content of flavonoids - beneficial antioxidants - by up to 90 per cent, which is why green tea is believed to offer different health benefits to black tea.
'Recent studies have also shown potent anticarcinogenic effects of green tea, attributed to its antioxidant properties.' Other research shows drinking green tea lowers 'bad' cholesterol and blood pressure, and reduces harmful liver enzymes. 'Evidence is now suggesting that drinking around 3 to 4 cups of tea a day may help reduce the risk of developing heart disease.