Effects of green tea catechin extract on serum lipids in postmenopausal women: a randomized, placebo-controlled clinical trial.
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.



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.



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.



Compared with placebo, 1-y supplementation with GTE capsules resulted in a significant reduction in circulating TC (-2.1% compared with 0.7%; P = 0.0004), LDL cholesterol (-4.1% compared with 0.9%; P < 0.0001) and non-HDL cholesterol (-3.1% 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).



Supplementation with GTE significantly reduced circulating TC and LDL-cholesterol concentrations, especially in those with elevated baseline TC concentrations. This trial was registered at clinicaltrials.gov as NCT00917735.
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
Hamed
H
Samavat
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN.
April R
AR
Newman
Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA.
Renwei
R
Wang
Division of Cancer Control and Population Sciences, University of Pittsburgh Cancer Institute, Pittsburgh, PA.|Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA; and.
Jian-Min
JM
Yuan
Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA.
Anna H
AH
Wu
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN; mkurzer@umn.edu.
Mindy S
MS
Kurzer
D000975:Antioxidants / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002392:Catechin / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood; D002394:Catechol O-Methyltransferase / Q000235:genetics / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D009765:Obesity / Q000097:blood; D010936:Plant Extracts / Q000008:administration & dosage*; D017698:Postmenopause / Q000097:blood*; D013662:Tea / Q000737:chemistry*; D016896:Treatment Outcome; D014280:Triglycerides / Q000097:blood
D000975:Antioxidants; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008055:Lipids; D010936:Plant Extracts; D013662:Tea; D014280:Triglycerides; D002392:Catechin; C045651:epigallocatechin gallate; D002394:Catechol O-Methyltransferase
EGCG; blood lipids; cardiovascular; green tea; postmenopausal; randomized controlled trial