title: Drinks containing anthocyanin-rich blackcurrant extract decrease postprandial blood glucose, insulin and incretin concentrations.
abstract: Blackcurrants are rich in polyphenolic glycosides called anthocyanins, which may inhibit postprandial glycemia. The aim was to determine the dose-dependent effects of blackcurrant extract on postprandial glycemia. Men and postmenopausal women (14M, 9W, mean age 46 years, S.D.=14) were enrolled into a randomized, double-blind, crossover trial. Low sugar fruit drinks containing blackcurrant extract providing 150-mg (L-BE), 300-mg (M-BE) and 600-mg (H-BE) total anthocyanins or no blackcurrant extract (CON) were administered immediately before a high-carbohydrate meal. Plasma glucose, insulin and incretins (GIP and GLP-1) were measured 0-120min, and plasma 8-isoprostane F2α, together with arterial stiffness by digital volume pulse (DVP) was measured at 0 and 120min. Early plasma glucose response was significantly reduced following H-BE (n=22), relative to CON, with a mean difference (95% CI) in area over baseline (AOB) 0-30min of -0.34mmol/l.h (-0.56, -0.11, P<.005); there were no differences between the intermediate doses and placebo. Plasma insulin concentrations (AOB 0-30min) were similarly reduced. Plasma GIP concentrations (AOB 0-120min) were significantly reduced following H-BE, with a mean difference of -46.6ng/l.h (-66.7, -26.5, P<.0001) compared to CON. Plasma GLP-1 concentrations were reduced following H-BE at 90min. There were no effects on 8-isoprostane F2αor vascular function. Consumption of blackcurrant extract in amounts roughly equivalent to 100-g blackcurrants reduced postprandial glycemia, insulinemia and incretin secretion, which suggests that inclusion of blackcurrant polyphenols in foods may provide cardio-metabolic health benefits. This trial was registered at clinicaltrials.gov as NCT01706653.
authors.affiliation: Diabetes & Nutritional Sciences Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK.
authors.forename: Monica L
authors.initials: ML
authors.lastname: Castro-Acosta
authors.affiliation: Diabetes & Nutritional Sciences Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK.
authors.forename: Leanne
authors.initials: L
authors.lastname: Smith
authors.affiliation: GlaxoSmithKline Services Unlimited, GSK House, 980 Great West Road, Middlesex, TW8 9GS, UK.
authors.forename: Rosalind J
authors.initials: RJ
authors.lastname: Miller
authors.affiliation: Suntory Beverage and Food Europe Ltd, 2 Longwalk Road, Stockley Park, Uxbridge UB11 1BA, UK.
authors.forename: Danielle I
authors.initials: DI
authors.lastname: McCarthy
authors.affiliation: Suntory Beverage and Food Europe Ltd, 2 Longwalk Road, Stockley Park, Uxbridge UB11 1BA, UK.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Farrimond
authors.affiliation: Diabetes & Nutritional Sciences Division, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK. Electronic address: wendy.hall@kcl.ac.uk.
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Hall
mesh_terms: D000328:Adult; D000872:Anthocyanins / Q000008:administration & dosage / Q000627:therapeutic use*; D001628:Beverages; D001786:Blood Glucose / Q000032:analysis; D018592:Cross-Over Studies; D000070601:Diet, Carbohydrate Loading / Q000009:adverse effects; D050528:Diet, Carbohydrate-Restricted; D004311:Double-Blind Method; D005260:Female; D005638:Fruit / Q000737:chemistry*; D055951:Functional Food; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000378:metabolism / Q000517:prevention & control*; D006946:Hyperinsulinism / Q000097:blood / Q000378:metabolism / Q000517:prevention & control; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D054795:Incretins / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism; D008297:Male; D062407:Meals; D008875:Middle Aged; D010936:Plant Extracts / Q000008:administration & dosage / Q000627:therapeutic use*; D019518:Postprandial Period; D031965:Ribes / Q000737:chemistry*
chemical_list: D000872:Anthocyanins; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D054795:Incretins; D010936:Plant Extracts
keywords: Anthocyanins; Berries; Incretins; Insulin; Polyphenols; Postprandial glycemia; Randomized controlled trial