Effects of green tea catechin extract on serum lipids in postmenopausal women: A randomized, placebo-controlled clinical trial1,2

Hamed Samavat, April R. Newman, Renwei Wang, Jian Min Yuan, Anna H. Wu, Mindy S. Kurzer

Research output: Contribution to journalArticlepeer-review

48 Scopus citations

Abstract

Background: Green tea has been suggested to improve cardiovascular disease risk factors, including circulating lipid variables. However, current evidence is predominantly based on small, short-term randomized controlled trials conducted in diverse populations. Objective: The aim of this study was to examine the efficacy and impact of green tea extract (GTE) supplementation high in epigallocatechin gallate (EGCG) on blood lipids in healthy postmenopausal women. Design: This was an ancillary study of a double-blind, randomized, placebo-controlled, parallel-arm trial investigating the effects of a GTE supplement containing 1315 mg catechins (843 mg EGCG) on biomarkers of breast cancer risk. Participants were randomly assigned to receive GTE (n = 538) or placebo (n = 537) and were stratified by catechol-O-methyltransferase (COMT) genotype activity (high COMT compared with low or intermediate COMT genotype activity). They consumed either 4 GTE or identical placebo capsules daily for 12 mo. A total of 936 women completed this substudy. Circulating lipid panels including total cholesterol (TC), HDL cholesterol, and triglycerides were measured at baseline and at months 6 and 12. Results: Compared with placebo, 1-y supplementation with GTE capsules resulted in a significant reduction in circulating TC (22.1% compared with 0.7%; P = 0.0004), LDL cholesterol (24.1% compared with 0.9%; P , 0.0001) and non-HDL cholesterol (23.1% compared with 0.4%; P = 0.0032). There was no change in HDL-cholesterol concentration, but triglyceride concentrations increased by 3.6% in the GTE group, whereas they decreased by 2.5% in the placebo group (P = 0.046). A significant reduction in TC was observed only among women with high (i.e., 200 mg/dL) baseline TC concentrations (P-interaction = 0.01) who consumed GTE capsules. The effect of GTE on the increase in triglycerides was mainly observed among obese women and statin users (P-interaction = 0.06). Conclusion: Supplementation with GTE significantly reduced circulating TC and LDL-cholesterol concentrations, especially in those with elevated baseline TC concentrations.

Original languageEnglish (US)
Pages (from-to)1671-1682
Number of pages12
JournalAmerican Journal of Clinical Nutrition
Volume104
Issue number6
DOIs
StatePublished - Dec 1 2016

Bibliographical note

Funding Information:
Supported by the NIH/National Cancer Institute (grant R01 CA127236), the Department of Defense/US Army Medical Research and Materiel Command (award W81XWH-11-1-0013), the Minnesota Agricultural Experiment Station (project MIN-18-103), the National Center for Advancing Translational Sciences of the NIH (award UL1TR000114), and the University of Minnesota Graduate School Doctoral Dissertation Fellowship. Corban Laboratories/Eniva Nutraceutics (Plymouth, MN) provided the study supplements.

Publisher Copyright:
© 2016 American Society for Nutrition.

Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

Keywords

  • Blood lipids
  • Cardiovascular
  • EGCG
  • Green tea
  • Postmenopausal
  • Randomized controlled trial

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