July 7, 2011
Green Tea Has Slight Affect On Cholesterol
Evidence from a new study suggests drinking green tea cuts "bad" cholesterol, a finding that may help explain why the beverage has been linked to a lower risk of heart disease, the leading cause of death worldwide.
Because few Americans drink green tea, encouraging them to do so could have significant health benefits, the authors of the new study reported in the American Journal of Clinical Nutrition.
Xin-Xin Zheng and colleagues from Peking Union Medical College in Beijing, China pooled the results of 14 previous trials for their study. In each of the previous studies, researchers divided participants into two groups: one that drank green tea or an extract for periods ranging from three weeks to three months, and one that got an inactive preparation.
Zheng's team found those who drank green tea ended up with total cholesterol levels that were 7.2 mg/dL lower than in the comparison group. Their bad cholesterol (LDL) dropped 2.2 mg/dL -- a decrease of nearly 2 percent. There was no difference in good cholesterol (HDL).
The cholesterol-lowering effects of green tea may stem from chemicals in it known as catechins, which decrease the absorption of cholesterol in the gut, according to Zheng.
Nathan Wong, head of the heart disease prevention program at University of California, Irvine, cautioned that the reduction in cholesterol was actually pretty small.
Green tea "should not be recommended in place of well-proven cholesterol-lowering medicines for people with high cholesterol," Wong told Reuters Health.
And some researchers believe heavy consumption of green tea or its extracts can lead to possible side effects. There have been a few dozen reports of liver damage, and the brew may also interact with some medications, reducing their effectiveness.
However, smaller doses of green tea "could be a useful component of a heart-healthy diet," Wong said, adding it may have benefits that go beyond its effect on cholesterol.
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