Green tea extract and catechol‐O‐methyltransferase genotype modify the post‐prandial serum insulin response in a randomised trial of overweight and obese post‐menopausal women

• Published in: Journal of human nutrition and dietetics 2017-04, Vol.30 (2), p.166-176
• Main Authors: Dostal, A. M., Arikawa, A., Espejo, L., Bedell, S., Kurzer, M. S., Stendell‐Hollis, N. R.
• Format: Article
• Language: English
• Subjects: Adiponectin - blood; Aged; Antioxidants - administration & dosage; Antioxidants - analysis; Body Mass Index; Carbohydrates; Catechin - administration & dosage; Catechin - analogs & derivatives; Catechol O-Methyltransferase - genetics; Dietary Supplements; Double-Blind Method; Enzymes; Female; Genotype; Genotype & phenotype; Ghrelin - blood; green tea; Humans; Insulin; Insulin - blood; insulin sensitivity; Leptin - blood; Middle Aged; Obesity; Obesity - blood; Overweight - blood; Plant Extracts - administration & dosage; Postmenopause; Postprandial Period - genetics; post‐menopausal women; post‐prandial response; satiety; Surveys and Questionnaires; Tea; Tea - chemistry; Womens health
• ISSN: 0952-3871; 1365-277X
• DOI: 10.1111/jhn.12408

Background Green tea extract (GTE) may be involved in a favourable post‐prandial response to high‐carbohydrate meals. The catechol‐O‐methyltransferase (COMT) genotype may modify these effects. We examined the acute effects of GTE supplementation on the post‐prandial response to a high‐carbohydrate meal by assessing appetite‐associated hormones and glucose homeostasis marker concentrations in women who consumed 843 mg of (−)‐epigallocatechin‐3‐gallate (EGCG) or placebo capsules for 11–12 months. Methods Sixty Caucasian post‐menopausal women (body mass index ≥ 25.0 kg m–2) were included in a randomised, double‐blind feeding study. GTE was consumed with a breakfast meal [2784.0 kJ (665.4 kcal); 67.2% carbohydrate]. Blood samples were drawn pre‐meal, post‐meal, and every 30 min for 4 h. Participants completed six satiety questionnaires. Results Plasma leptin, ghrelin and adiponectin did not differ between GTE and placebo at any time point; COMT genotype did not modify these results. Participants randomised to GTE with the high‐activity form of COMT (GTE‐high COMT) had higher insulin concentrations at time 0, 0.5 and 1.0 h post‐meal compared to all COMT groups randomised to placebo. Insulin remained higher in the GTE‐high COMT group at 1.5, 2.0 and 2.5 h compared to Placebo‐low COMT (P