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.
The study, performed by Dr Nikolaos Alexopoulos and colleagues at the
1st Cardiology Department, Athens Medical School in Greece, was a
randomized trial involving 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
(following a brief period of ischemia of the upper limb) is related to
endothelial function and is known to be an independent predictor of
cardiovascular risk.2
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.
Green tea, which originates in China but is now consumed throughout the
world, is made with pure leaves, and has undergone little oxidization
during processing. The cardiovascular benefits of all teas - as well as
dark chocolate and red wine - are attributed to the flavonoids they
contain and their antioxidant activity.3 However, says investigator Dr.
Charalambos Vlachopoulos, flavonoids in green tea are probably more
potent antioxidants than in black tea because there has been no
oxidization.
"These findings have important clinical implications," says Dr
Vlachopoulos. "Tea consumption has been associated with reduced
cardiovascular morbidity and mortality in several studies. Green tea is
consumed less in the Western world than black tea, but it could be more
beneficial because of the way it seems to improve endothelial function.
In this same context, recent studies have also shown potent
anticarcinogenic effects of green tea, attributed to its antioxidant
properties."
Posts
0 comments:
Post a Comment