Anthocyanin-enriched bilberry extract attenuates glycaemic response in overweight volunteers without changes in insulin. (January 2020)

• Record Type: Journal Article
• Authors: Alnajjar, Mahasin; Kumar Barik, Sisir; Bestwick, Charles; Campbell, Fiona; Cruickshank, Morven; Farquharson, Freda; Holtrop, Grietje; Horgan, Graham; Louis, Petra; Moar, Kim-Marie; Russell, Wendy R; Scobbie, Lorraine; Hoggard, Nigel
• Is Part Of: Journal of functional foods. Volume 64(2020)
• Publication Date: 2020-01
• Subjects: Bilberry -- Anthocyanins -- Type 2 diabetes -- Glycaemic response; T2D type 2 diabetes -- BMI body mass index -- OGTT oral glucose tolerance test -- w/w weight for weight -- AUCi incremental area under the curve -- MCP-1 monocyte chemoattractant protein-1 -- TEAC trolox equivalent antioxidant capacity -- FRAP fluorescence recovery after photobleaching -- LDL low-density lipoprotein -- IL-6 interleukin 6 -- COPD chronic obstructive pulmonary disease -- NOSRES north of Scotland research ethics -- HOMA homeostasis model assessment -- ELISA enzyme-linked immunosorbent assay -- HDL high-density lipoprotein -- NEFAs non-esterified fatty acids -- SD standard deviation -- GI gastrointestinal -- SGLT1 sodium glucose co-transporter 1 -- hsCRP high sensitivity C-Reactive Protein -- ApoA1 Apolipoprotein A1 -- sVCAM-1 soluble vascular cell adhesion molecule-1 -- sICAM-1 soluble intracellular adhesion molecule-1 -- HOMA-IR Homeostatic model assessment of insulin resistance -- HOMA-beta Homeostatic model assessment of beta cell function -- ApoB Apolipoprotein B-100 -- HbA1c Haemoglobin A1c -- TNFα Tumour necrosis factor alpha -- BODIPYL boron-dipyrromethene -- pNPG 4-Nitrophenyl-beta-D-glucopyranoside -- EMEM Eagle's Minimum Essential Medium -- CTB cell titre blue -- AUC area under curve -- 2DG 2-Deoxy-D-glucose -- GLUT2 glucose transporter 2 -- RESAS Rural and Environment Science and Analytical Services; Functional foods -- Analysis -- Periodicals; Food -- Biotechnology -- Periodicals; Nutrition -- Periodicals; 613.2
• DOI: 10.1016/j.jff.2019.103597
• Languages: English
• ISSNs: 1756-4646

Abstract

Graphical abstract: Highlights: This study investigated the effect of a three week supplementation of concentrated bilberry extract on glucose metabolism to determine what the initial mechanisms are causing the improvement in glucose homeostasis. This study demonstrates that the ingestion of a concentrated bilberry extract over a three week intervention period reduces postprandial glycaemia without changes in insulin. We show that the mechanism for the early decreased glycaemic response involves reduced rates of carbohydrate digestion/absorption. There was no change in anti-inflammatory markers (hsCRP, MCP-1, leptin), markers of vascular health (Apo A1, sVCAM-1, sICAM-1) in the plasma, reducing potential and radical scavenging capacity (as assayed through use of electron transfer [ET] and ET/hydrogen atom transfer based assays FRAP and TEAC respectively (Huang, Ou, & Prior, 2005; Apak et al., 2016) in plasma or change in the faecal bacterial microbiota measured between the volunteers receiving the bilberry extract and the placebo. Abstract: This study investigated the effect of a three week supplementation of bilberry extract on glucose metabolism. Overweight volunteers (n = 16; BMI 31) were given three capsules of either 0.47 g bilberry extract (36% (w/w) anthocyanins) or placebo per day for three weeks in a double blinded cross over intervention. The ingestion of the bilberry extract decreased the OGTT AUCi for glucose (20%; p = 0.008) but not for insulin compared with the placebo. There was no change in anti-inflammatory markers (hsCRP, MCP-1, leptin), vascular health markers (Apo A1, sVCAM-1, sICAM-1), reducing potential/ radical scavenging capacity or faecal bacterial microbiota. In vitro studies showed that the bilberry extract decreased α-amylase activity (p < 0.0001), α-glucosidase activity (p < 0.0001) and glucose uptake (p < 0.0001). This study demonstrates that the ingestion of a bilberry extract over a three week intervention period reduces postprandial glycaemia without changes in insulin. This is probably due to reduced rates of carbohydrate digestion and/or absorption.