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 (14 M, 9 W, mean age 46 y, SD 14) were enrolled into a randomized, double-blind, crossover trial. Low sugar fruit drinks containing blackcurrant extract providing150 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 0-120 min, and plasma 8-isoprostane F2α, together with arterial stiffness by digital volume pulse (DVP) were measured at 0 and 120 min. 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 -0.34 mmol/L.h (-0.56, -0.11, P <0.005); there were no differences between the intermediate doses and placebo. Plasma insulin concentrations (AOB 0-30 min) were similarly reduced. Plasma GIP concentrations (AOB 0-120 min) were significantly reduced following H-BE, with a mean difference of -46.6 ng/L.h (-66.7,-26.5, P <0.0001) compared to CON. Plasma GLP-1 concentrations were reduced following H-BE at 90 min. There were no effects on 8-isoprostane F2α, or 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.
Original language | English |
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Pages (from-to) | 154-161 |
Journal | JOURNAL OF NUTRITIONAL BIOCHEMISTRY |
Volume | 38 |
Early online date | 14 Sept 2016 |
DOIs | |
Publication status | E-pub ahead of print - 14 Sept 2016 |
Keywords
- Randomized controlled trial
- Clinical trial
- Postprandial glycemia
- Incretins
- Insulin
- Glucose
- Anthocyanins
- Polyphenols
- Berries
- Healthy volunteers