Intake of polyphenol-rich pomegranate pure juice influences urinary glucocorticoids, blood pressure and homeostasis model assessment of insulin resistance in human volunteers

Tsang, Catherine and Smail, Nacer Foudil and Almoosawi, Suzana and Davidson, Isobel and Al-Dujaili, Emad A S (2012) Intake of polyphenol-rich pomegranate pure juice influences urinary glucocorticoids, blood pressure and homeostasis model assessment of insulin resistance in human volunteers. Journal of Nutritional Science, 1. ISSN 2048-6790

[img] PDF (The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution-NonCommercial-ShareAlike licence )
3109.pdf
Available under License Creative Commons Attribution Non-commercial Share Alike.

Download (890kB)
Official URL: http://dx.doi.org/10.1017/jns.2012.10

Abstract

Pomegranate juice (PJ; also known as pomegreat pure juice) provides a rich and varied source of polyphenolic compounds that may offer cardioprotective, anti-atherogenic and antihypertensive effects. The aim of this study was to investigate the effect of PJ consumption on glucocorticoids levels, blood pressure (BP) and insulin resistance in volunteers at high CVD risk. Subjects (twelve males and sixteen females) participated in a randomised, placebo-controlled cross-over study (BMI: 26·77 (sd 3·36) kg/m2; mean age: 50·4 (sd 6·1) years). Volunteers were assessed at baseline, and at weeks 2 and 4 for anthropometry, BP and pulse wave velocity. Cortisol and cortisone levels in urine and saliva were determined by specific ELISA methods, and the cortisol/cortisone ratio was calculated. Fasting blood samples were obtained to assess plasma lipids, glucose, insulin and insulin resistance (homeostasis model assessment of insulin resistance). Volunteers consumed 500 ml of PJ or 500 ml of a placebo drink containing a similar amount of energy. Cortisol urinary output was reduced but not significant. However, cortisol/cortisone ratios in urine (P = 0·009) and saliva (P = 0·024) were significantly decreased. Systolic BP decreased from 136·4 (sd 6·3) to 128·9 (sd 5·1) mmHg (P = 0·034), and diastolic BP from 80·3 (sd 4·29) to 75·5 (sd 5·17) mmHg (P = 0·031) after 4 weeks of fruit juice consumption. Pulse wave velocity decreased from 7·5 (sd 0·86) to 7·44 (sd 0·94) m/s (P = 0·035). There was also a significant reduction in fasting plasma insulin from 9·36 (sd 5·8) to 7·53 (sd 4·12) mIU/l (P = 0·025) and of homeostasis model assessment of insulin resistance (from 2·216 (sd 1·43) to 1·82 (sd 1·12), P = 0·028). No significant changes were seen in the placebo arm of the study. These results suggest that PJ consumption can alleviate key cardiovascular risk factors in overweight and obese subjects that might be due to a reduction in both systolic and diastolic BP, possibly through the inhibition of 11β-hydroxysteroid dehydrogenase type 1 enzyme activity as evidenced by the reduction in the cortisol/cortisone ratio. The reduction in insulin resistance might have therapeutic benefits for patients with non-insulin-dependent diabetes, obesity and the metabolic syndrome.

Item Type: Article
Uncontrolled Keywords: Pomegranate juice; Blood pressure; Glucocorticoids; Obesity; 11β-Hydroxysteroid dehydrogenase; Homeostasis model assessment of insulin resistance
Divisions: School of Health Sciences > Dietetics, Nutrition and Biological Sciences
Date Deposited: 21 Jan 2013 14:49
Last Modified: 02 Feb 2017 15:42
URI: http://eresearch.qmu.ac.uk/id/eprint/3109

Statistics

Downloads
Activity Overview
752Downloads
459Hits

Altmetric

Actions (login required)

Edit Item Edit Item