QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 139/1/58    most recent jn.108.096412v1 Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Frank, J. Articles by Rimbach, G. Search for Related Content PubMed PubMed Citation Articles by Frank, J. Articles by Rimbach, G.

---

Nutrient Physiology, Metabolism, and Nutrient-Nutrient Interactions

Daily Consumption of an Aqueous Green Tea Extract Supplement Does Not Impair Liver Function or Alter Cardiovascular Disease Risk Biomarkers in Healthy Men^1,2

³ Institute of Human Nutrition and Food Science, Christian-Albrechts-University, 24118 Kiel, Germany; ⁴ Hugh Sinclair Human Nutrition Group, School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Reading RG6 6AP, United Kingdom; and ⁵ Division of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7HX, United Kingdom

Regular consumption of green tea polyphenols (GTP) is thought to reduce the risk of cardiovascular disease (CVD) but has also been associated with liver toxicity. The present trial aimed to assess the safety and potential CVD health beneficial effects of daily GTP consumption. We conducted a placebo-controlled parallel study to evaluate the chronic effects of GTP on liver function and CVD risk biomarkers in healthy men. Volunteers (treatment: n = 17, BMI 26.7 ± 3.3 kg/m², age 41 ± 9 y; placebo, n = 16, BMI 25.4 ± 3.3 kg/m², age 40 ± 10 y) consumed for 3 wk 6 capsules per day (2 before each principal meal) containing green tea extracts (equivalent to 714 mg/d GTP) or placebo. At the beginning and end of the intervention period, we collected blood samples from fasting subjects and measured vascular tone using Laser Doppler Iontophoresis. Biomarkers of liver function and CVD risk (including blood pressure, plasma lipids, and asymmetric dimethylarginine) were unaffected by GTP consumption. After treatment, the ratio of total:HDL cholesterol was significantly reduced in participants taking GTP capsules compared with baseline. Endothelial-dependent and -independent vascular reactivity did not significantly differ between treatments. In conclusion, the present data suggests that the daily consumption of high doses of GTP by healthy men for 3 wk is safe but without effects on CVD risk biomarkers other than the total:HDL cholesterol ratio.

^* To whom correspondence should be addressed. E-mail: frank{at}foodsci.uni-kiel.de.

Manuscript received 15 July 2008. Initial review completed 27 August 2008. Revision accepted 3 November 2008.

Published online 3 December 2008.