Enriched Green Tea Extract Lowers Cholesterol
Adults with high cholesterol who are consuming a low-fat diet may be able to reduce their LDL ("bad") and total cholesterol levels and increase their HDL ("good") cholesterol level by taking a green tea extract enriched with theaflavin, according to a study in Archives of Internal Medicine (2003;163:1448–53). The findings of this study suggest that this theaflavin-enriched green tea extract is an effective adjunctive treatment to a low-fat diet in improving cholesterol levels.
Green tea (Camellia sinensis) is the second most widely consumed beverage in the world after water. It possesses antioxidant and anti-cancer properties due to substances in the tea called flavonoids. Theaflavins are specific types of flavonoids that are produced when green tea is fermented into black tea. Preliminary studies in animals suggest that theaflavins and other flavonoids block the production of cholesterol in the body and increase cholesterol excretion. A few small studies in humans have failed to show any benefit in decreasing cholesterol by consuming either green or black tea or by taking a green tea extract. This is the first study to examine the effects of a green tea extract enriched with theaflavins.
In the study, 220 adults aged 18 years and older with high cholesterol who were following a low-fat diet were randomly assigned to receive 1 capsule per day of green tea extract with theaflavins (providing 75 mg of theaflavins, 150 mg of green tea catechins, and 150 mg of other green tea polyphenols) or a similar placebo for 12 weeks. Blood measurements of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides were taken initially, four weeks after starting treatment, and then at the conclusion of the study.
Total cholesterol and LDL cholesterol dropped 11 and 16%, respectively, in those taking green tea extract. HDL cholesterol and triglycerides increased marginally, but these changes were not statistically significant. No significant change in any blood lipid measurement was observed in those taking the placebo. The green tea extract was well tolerated by all participants who received it.
The participants in this study were already consuming a low-fat diet, so it is unclear what effect the green tea extract would have on people with high cholesterol who consume a standard Western diet. Nonetheless, the results from this study are significant. Previously published studies suggest that decreasing LDL cholesterol by 16% could lower the risk of having a heart attack or stroke by as much as 24%. More long-term studies are necessary to determine if this is true.
Other herbs that may lower cholesterol levels include garlic and gugulipid. Several studies have also shown policosanol, red yeast rice, soy protein, and niacin significantly decrease cholesterol. People should consult a healthcare professional for specific information on appropriate amounts to take.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of The Natural Pharmacist: Lowering Cholesterol (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice at New England Family Health Associates located in Southport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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