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 - Tập 1 - 2012
Catherine Tsang1, Nacer Foudil Smail1, Suzana Almoosawi1, Isobel Davidson1, Emad A.S. Al‐Dujaili1
1Department of Dietetics, Nutrition and Biological Sciences, Queen Margaret University, Queen Margaret University Drive, Musselburgh, East Lothian EH21 6UU, UK.

Tóm tắt

AbstractPomegranate 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 (sd3·36) kg/m2; mean age: 50·4 (sd6·1) 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.

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Tài liệu tham khảo

10.1016/j.mam.2010.09.005

Aviram, 2000, Pomegranate juice consumption reduces oxidative stress, atherogenic modifications to LDL, and platelet aggregation: studies in humans and in atherosclerotic apolipoprotein E-deficient mice, Am J Clin Nutr, 71, 1062, 10.1093/ajcn/71.5.1062

Grassi, 2005, Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons, Am J Clin Nutr, 81, 611, 10.1093/ajcn/81.3.611

10.1007/BF00280883

10.1016/j.mce.2010.12.011

10.1046/j.1365-2265.1996.00853.x

10.1021/jf061674h

10.1021/jf9025794

10.1073/pnas.0505870102

10.1016/j.amjcard.2005.05.026

10.1038/oby.2005.137

10.1016/j.clnu.2003.10.002

10.1016/S0140-6736(88)90742-8

10.1042/cs0830171

10.1089/jmf.2004.7.305

10.1016/j.amjcard.2009.05.037

10.1016/j.foodchem.2008.11.093

10.1016/j.foodchem.2009.01.044

10.1016/j.nut.2012.01.001

10.1002/9780470988558.ch7

10.1016/S0891-5849(03)00185-0

Serafini, 1998, Alcohol-free red wine enhances plasma antioxidant capacity in humans, J Nutr, 128, 1003, 10.1093/jn/128.6.1003

10.1021/jf103894m

10.1017/S0007114510003922

10.2337/db08-0495

10.1042/CS20090369

10.1007/s00394-004-0461-7

10.1021/jf000404a

10.1161/01.HYP.0000253258.36141.c7

Kaplan, 2001, Pomegranate juice supplementation to atherosclerotic mice reduces macrophage lipid peroxidation, cellular cholesterol accumulation and development of atherosclerosis, J Nutr, 131, 2082, 10.1093/jn/131.8.2082

10.1016/j.atherosclerosis.2005.09.006

10.1016/S0026-0495(99)90135-X

10.1210/jcem.85.11.6946

10.1016/j.niox.2005.12.004

Seeram, 2006, Pomegranate juice ellagitannin metabolites are present in human plasma and some persist in urine for up to 48 hours, J Nutr, 136, 2481, 10.1093/jn/136.10.2481

10.1042/CS20090063

10.1016/j.ctcp.2010.09.004

10.1210/jc.2007-0334

10.1016/j.jnutbio.2005.01.006

10.1021/jf050384i

10.1021/jf0012502

10.1093/jnci/95.5.346

Manach, 2004, Polyphenols: food sources and bioavailability, Am J Clin Nutr, 79, 727, 10.1093/ajcn/79.5.727

10.1161/01.HYP.0000151325.83008.b4

10.1023/A:1014405730585

10.1016/j.nbd.2006.08.006

10.1016/j.niox.2006.03.001

10.1111/j.1753-4887.2008.00133.x

10.1016/S0021-9150(01)00412-9

Singleton, 1965, Colorimetry of total phenolics with phosphomolybdic–phosphotungstic reagents, Am J Enol Vitol, 16, 144, 10.5344/ajev.1965.16.3.144

10.1093/ije/27.5.808

10.1021/jf073035s

10.1177/0003319711416108

10.1006/abio.1996.0292

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Journal of Nutritional Science

Tập 1

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