title: Effect of 2-month controlled green tea intervention on lipoprotein cholesterol, glucose, and hormone levels in healthy postmenopausal women.
abstract: There have been no controlled intervention studies to investigate the effects of green tea on circulating hormone levels, an established breast cancer risk factor. We conducted a double-blind, randomized, placebo-controlled intervention study to investigate the effect of the main green tea catechin, epigallocatechin gallate (EGCG), taken in a green tea extract, polyphenon E (PPE). Postmenopausal women (n = 103) were randomized into three arms: placebo, 400-mg EGCG as PPE, or 800-mg EGCG as PPE as capsules per day for 2 months. Urinary tea catechin and serum estrogen, androgen, lipid, glucose-related markers, adiponectin, and growth factor levels were measured at baseline and at the end of months 1 and 2 of intervention. On the basis of urinary tea catechin concentrations, compliance was excellent. Supplementation with PPE did not produce consistent patterns of changes in estradiol (E2), estrone (E1), or testosterone (T) levels. Low-density lipoprotein (LDL)-cholesterol decreased significantly in both PPE groups but was unchanged in the placebo group; the change in LDL-cholesterol differed between the placebo and PPE groups (P = 0.02). Glucose and insulin levels decreased nonsignificantly in the PPE groups but increased in the placebo group; statistically significant differences in changes in glucose (P = 0.008) and insulin (P = 0.01) were found. In summary, green tea (400- and 800-mg EGCG as PPE; ∼5-10 cups) supplementation for 2 months had suggestive beneficial effects on LDL-cholesterol concentrations and glucose-related markers.
authors.affiliation: Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California, USA. annawu@usc.edu
authors.forename: Anna H
authors.initials: AH
authors.lastname: Wu
authors.forename: Darcy
authors.initials: D
authors.lastname: Spicer
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.forename: Chiu-Chen
authors.initials: CC
authors.lastname: Tseng
authors.forename: Chung S
authors.initials: CS
authors.lastname: Yang
authors.forename: Malcolm C
authors.initials: MC
authors.lastname: Pike
mesh_terms: D000728:Androgens / Q000097:blood*; D002392:Catechin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000652:urine; D002784:Cholesterol / Q000097:blood*; D004311:Double-Blind Method; D004967:Estrogens / Q000097:blood*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008875:Middle Aged; D017698:Postmenopause; D011379:Prognosis; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013662:Tea; D013997:Time Factors; D016387:Women's Health
chemical_list: D000728:Androgens; D004967:Estrogens; D008074:Lipoproteins; D012738:Sex Hormone-Binding Globulin; D013662:Tea; C030104:lipoprotein cholesterol; D002392:Catechin; D002784:Cholesterol; C045651:epigallocatechin gallate; D005947:Glucose