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Green Tea Catechins Fight Unwanted Clumping of Blood Platelets Background:
One theory of cardiovascular disease is that it begins with a injury to the wall
of a blood vessel. To help that injury heal, the platelets in the blood release a substance called
thromboxane. The good
news is that thromboxane causes the platelets to clump together and form a plug that
seals the wound. The bad news is that this plug may block an artery and cause a
heart attack or stroke.
Doctors have used "blood thinners" to treat the problem of
sticky platelets for years. The two main types of blood thinners are
antiplatelets, which interfere with the clumping of the platelets, and
anticoagulants, which inhibit the clotting factors in the blood. The trouble
with anticoagulants is they can work so well that you may develop bleeding in the brain.
Antiplatelets are considered the safer option.
Korean researchers knew that green tea catechins could
inhibit clot formation in the blood, but they wanted to find out how the
catechins did it. Was
it because the catechins worked against certain clotting factors in the blood,
like the anticoagulants? Or was it because they inhibited platelet "stickiness,"
the safer method?
Type of study: "Test-tube" and animal
Study methods: Green tea catechins and
EGCg were tested on human platelets in "test tubes," and in mice that had blood
clots in their lungs.
What happened: The catechins inhibited
platelet clumping, but did not change certain measures of blood coagulation.
Researchers' conclusion: The green tea
catechins' "blood thinning" actions "... may be due to the antiplatelet
activities but not to anticoagulation activities."
Citation: Kang WS, Lim IH, Yuk DY, et al.
Antithrombotic activities of green tea catechins and (-)- epigallocatechin
gallate. Thromb Res 1999;96(3):229-37. (Click
here to read PubMed study abstract.)
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Nadine Taylor, M.S., R.D. presents
GreenTeaLibrary.com,
the most comprehensive collection of scientific information
describing the health benefits of green tea.
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