By Michael Kahn
LONDON (Reuters) - A few cups of green tea each day mayhelp prevent heart disease, Greek researchers said onWednesday.
A study published in the European Journal of CardiovascularPrevention and Rehabilitation showed further evidence of thepotential health benefits from a brew already linked to areduced risk of a range of cancers and other conditions.
The study showed that green tea improves blood flow and theability of arteries to relax, said Charalambos Vlachopoulos, acardiologist at the Athens Medical School in Greece who workedon the study.
Other studies have shown that black tea also has benefitsfor cardiovascular health.
The Greek team said they believed green tea might be evenbetter because it had higher quantities of beneficial compoundscalled flavonoids -- some of which are lost in the oxidationprocess that black tea undergoes.
Flavonoids are also found in cocoa, tomatoes and grapes.
"A couple of cups a day would probably be a good dose forpeople," Vlachopoulos said. "This is the first study to showthese effects for green tea."
The researchers gave 14 healthy volunteers either greentea, diluted caffeine or hot water on three separate occasionsand then measured the function of endothelial cells lining thecirculatory system.
These cells help relax arteries and ease blood flow.
"What is important is these effects are evident fairlyrapidly, within 30 minutes," Vlachopoulos said.
The measurements taken 30, 90 and 120 minutes followingconsumption showed an almost immediate benefit among people whohad drunk green tea, he said.
Heart disease is the world's leading cause of death. It iscaused by fatty deposits that harden and block arteries, highblood pressure which damages blood vessels, and other factors.
While the researchers looked only at a short-term impact,Vlachopolous said the team's not-yet-published studies suggestthe protection is long lasting.
"Green tea is consumed less in the Western world than blacktea, but it could be more beneficial because of the way itseems to improve (circulatory) function," he said.
(Editing by Bate Felix)