Strawberry and cranberry polyphenols improve insulin sensitivity in insulin-resistant, non-diabetic adults: a parallel, double-blind, controlled and randomised clinical trial. Issue 4 (14th March 2017)

• Record Type: Journal Article
• Authors: Paquette, Martine; Medina Larqué, Ana S.; Weisnagel, S. J.; Desjardins, Yves; Marois, Julie; Pilon, Geneviève; Dudonné, Stéphanie; Marette, André; Jacques, Hélène
• Is Part Of: British journal of nutrition. Volume 117:Issue 4(2017)
• Page Start: 519
• Page End: 531
• Publication Date: 2017-03-14
• Subjects: Polyphenols, -- Strawberries, -- Cranberries, -- Insulin sensitivity, -- Glucose metabolism, -- Insulin secretion, -- Insulin-resistant subjects; Nutrition -- Periodicals; 572.4
• DOI: 10.1017/S0007114517000393
• Languages: English
• ISSNs: 0007-1145

Abstract

Abstract: Plant-derived foods rich in polyphenols are associated with several cardiometabolic health benefits, such as reduced postprandial hyperglycaemia. However, their impact on whole-body insulin sensitivity using the hyperinsulinaemic-euglycaemic clamp technique remains under-studied. We aimed to determine the effects of strawberry and cranberry polyphenols (SCP) on insulin sensitivity, glucose tolerance, insulin secretion, lipid profile, inflammation and oxidative stress markers in free-living insulin-resistant overweight or obese human subjects ( n 41) in a parallel, double-blind, controlled and randomised clinical trial. The experimental group consumed an SCP beverage (333 mg SCP) daily for 6 weeks, whereas the Control group received a flavour-matched Control beverage that contained 0 mg SCP. At the beginning and at the end of the experimental period, insulin sensitivity was assessed by a hyperinsulinaemic-euglycaemic clamp, and glucose tolerance and insulin secretion by a 2-h oral glucose tolerance test (OGTT). Insulin sensitivity increased in the SCP group as compared with the Control group (+0·9 (sem 0·5)×10 −3 v . −0·5 (sem 0·5)×10 −3 mg/kg per min per pmol, respectively, P =0·03). Compared with the Control group, the SCP group had a lower first-phase insulin secretion response as measured by C-peptide levels during the first 30 min of the OGTT ( P =0·002). No differences were detected between the two groups for lipids and markers of inflammation and oxidative stress. A 6-week dietary intervention with 333 mg of polyphenols from strawberries and cranberries improved insulin sensitivity in overweight and obese non-diabetic, insulin-resistant human subjects but was not effective in improving other cardiometabolic risk factors.