Nutritional intervention and impact of polyphenol on glycohaemoglobin (HbA1c) in non-diabetic and type 2 diabetic subjects: systematic review and meta-analysis

Palma Duran, S. A., Vlassopoulos, A., Lean, M. , Govan, L. and Combet, E. (2017) Nutritional intervention and impact of polyphenol on glycohaemoglobin (HbA1c) in non-diabetic and type 2 diabetic subjects: systematic review and meta-analysis. Critical Reviews in Food Science and Nutrition, 57(5), pp. 975-986. (doi: 10.1080/10408398.2014.973932) (PMID:25746842)

Abstract

Polyphenols have been extensively studied for their antioxidant and anti-inflammatory properties. Recently, their antiglycative actions by oxidative stress modulation have been linked to prevention of diabetes and associated complications. This paper assesses the evidence for polyphenol interventions on glycohaemoglobin (HbA1c) in non-diabetic, pre-diabetic and type 2 diabetes mellitus (T2DM) subjects. A systematic review of polyphenols clinical trials on HbA1c in humans was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis. Thirty-six controlled randomized trials with HbA1c values were included. Polyphenols (extracts, supplements, foods), were supplemented (28 mg to 1.5g) for 0.7 to 12 months. Combining all subjects (n=1954, mean baseline HbA1c=7.03%, 53 mmol/mol), polyphenol supplementation significantly (p<0.001) lowered HbA1c% by -0.53±0.12 units (-5.79±0.13 mmol/mol). This reduction was significant (p<0.001) in T2DM subjects, specifically (n=1426, mean baseline HbA1c=7.44%, 58 mmol/mol), with HbA1c% lowered by -0.21±0.04 units (-2.29±0.4 mmol/mol). Polyphenol supplementation had no significant effect (p>0.21) in the non-diabetic (n=258, mean baseline HbA1c=5.47%, 36 mmol/mol) and the pre-diabetic subjects (n=270, mean baseline HbA1c=6.06%, 43 mmol/mol) strata: -0.39±0.27 HbA1c% units (-4.3±0.3 mmol/mol), and -0.38±0.31 units (-4.2±0.31 mmol/mol), respectively. In conclusion, polyphenols can successfully reduce HbA1c in T2DM, without any intervention at glycaemia, and could contribute to the prevention of diabetes complications.

• Item Type: Articles
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Critical Reviews in Food Science and Nutrition on 06/03/15, available online: http://wwww.tandfonline.com/10.1080/10408398.2014.973932
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Govan, Dr Lindsay and Lean, Professor Michael and Combet Aspray, Professor Emilie
• Authors: Palma Duran, S. A., Vlassopoulos, A., Lean, M., Govan, L., and Combet, E.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Health Economics and Health Technology Assessment; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Critical Reviews in Food Science and Nutrition
• Publisher: Taylor and Francis
• ISSN: 1040-8398
• ISSN (Online): 1549-7852
• Published Online: 06 March 2015
• Copyright Holders: Copyright © 2015 Taylor & Francis
• First Published: First published in Critical Reviews in Food Science and Nutrition 2015
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher