George Trevor W, Niwat Chutamat, Waroonphan Saran, Gordon Michael H, Lovegrove Julie A
Department of Food Biosciences, School of Chemistry, Food Biosciences and Pharmacy, The University of Reading, Whiteknights, Reading, Berks, UK.
Proc Nutr Soc. 2009 May;68(2):148-61. doi: 10.1017/S0029665109001165. Epub 2009 Mar 17.
The average UK adult consumes less than three portions of fruit and vegetables daily, despite evidence to suggest that consuming five portions daily could help prevent chronic diseases. It is recommended that fruit juice should only count as one of these portions, as juicing removes fibre and releases sugars. However, fruit juices contain beneficial compounds such as vitamin C and flavonoids and could be a useful source of dietary phytochemicals. Two randomised controlled cross-over intervention studies investigating the effects of chronic and acute consumption of commercially-available fruit- and vegetable-puree-based drinks (FVPD) on bioavailability, antioxidant status and CVD risk factors are described. Blood and urine samples were collected during both studies and vascular tone was measured using laser Doppler imaging. In the chronic intervention study FVPD consumption was found to significantly increase dietary carotenoids (P=0.001) and vitamin C (P=0.003). Plasma carotenoids were increased (P=0.001), but the increase in plasma vitamin C was not significant. There were no significant effects on oxidative stress, antioxidant status and other CVD risk factors. In the acute intervention study FVPD were found to increase total plasma nitrate and nitrite (P=0.001) and plasma vitamin C (P=0.002). There was no effect on plasma lipids or uric acid, but there was a lower glucose and insulin peak concentration after consumption of the FVPD compared with the sugar-matched control. There was a trend towards increased vasodilation following both chronic and acute FVPD consumption. All volunteers were retrospectively genotyped for the eNOS G298T polymorphism and the effect of genotype on the measurements is discussed. Overall, there was a non-significant trend towards increased endothelium-dependent vasodilation following both acute and chronic FVPD consumption. However, there was a significant time x treatment effect (P<0.05) of acute FVPD consumption in individuals with the GG variant of the eNOS gene.
英国成年人平均每天摄入的水果和蔬菜不足三份，尽管有证据表明每天摄入五份有助于预防慢性病。建议果汁只能算作其中一份，因为榨汁会去除纤维并释放糖分。然而，果汁含有有益化合物，如维生素C和类黄酮，可能是膳食植物化学物质的有用来源。本文描述了两项随机对照交叉干预研究，调查了长期和短期饮用市售水果和蔬菜泥基饮料（FVPD）对生物利用度、抗氧化状态和心血管疾病风险因素的影响。两项研究均采集了血液和尿液样本，并使用激光多普勒成像测量血管张力。在长期干预研究中，发现饮用FVPD可显著增加膳食类胡萝卜素（P=0.001）和维生素C（P=0.003）。血浆类胡萝卜素增加（P=0.001），但血浆维生素C的增加不显著。对氧化应激、抗氧化状态和其他心血管疾病风险因素没有显著影响。在短期干预研究中，发现FVPD可增加血浆总硝酸盐和亚硝酸盐（P=0.001）以及血浆维生素C（P=0.002）。对血脂或尿酸没有影响，但与糖匹配的对照组相比，饮用FVPD后葡萄糖和胰岛素的峰值浓度较低。长期和短期饮用FVPD后均有血管舒张增加的趋势。所有志愿者均进行了eNOS G298T多态性的回顾性基因分型，并讨论了基因型对测量结果的影响。总体而言，长期和短期饮用FVPD后内皮依赖性血管舒张均有不显著的增加趋势。然而，在eNOS基因GG变体个体中，短期饮用FVPD有显著的时间×治疗效应（P<0.05）。
