眼睛的营养素：维生素C有助预防白内障 Vitamin C for preventing cataract
By Shana Hopkins, WAC Nutritionist
维生素C再次显示它在战胜疾病中的力量。这一次维生素C证明可以预防白内障的早期出现。白内障在眼球内晶状体变得混浊时出现，最常见在老年人中，尤其是75岁以上的老人。在这一期的美国临床营养学杂志（AJCN 2002;75:540）上刊登一个新的研究报告，报告收集了年龄介乎53~73岁的妇女的有关资料。他们发现，每天摄取362毫克或以上的60岁以下的妇女，形成楔状性白内障的风险比哪些每天只摄取140毫克的人减少57%。对比哪些不服用补充剂的妇女，哪些服用维生素C10年或以上的妇女减少她们患白内障的风险达60%。这是另一个以富含维生素C的食物如辣椒、木瓜、哈密瓜，花椰菜、和草莓，以及每天额外补充100~500毫克的维生素C来支持你的身体的理由。
大多数人认为维生素C可以预防感冒和感染，但据研究人员说，维生素C在保持我们的眼睛健康方面也起着重要作用。维生素C(抗坏血酸)是一种抗氧化剂，天然存在于水果和蔬菜中。据美国眼科协会 在年龄相关性眼病研究期间发现,维生素C可以保护视力降低白内障的风险,和其他重要的营养物质,可以减缓病情发展所谓的年龄相关性黄斑变性(AMD)和视力丧失。考虑到超过2500万人患有AMD和白内障的形成，潜在的治愈或预防措施是值得探索的。
来源：
https://www.health24.com/Medical/Eye/About-eye/Boost-your-eye-health-with-vitamin-C-20150922
ScientificWorldJournal. 2014; 2014: 750634.
Vitamin C Protected Human Retinal Pigmented Epithelium from Oxidant Injury Depending on Regulating SIRT1
Wei Wei, 1 Langen Li, 1 Yufeng Zhang, 1 Geriletu, 1 Jia Yang, 2 Yanmei Zhang, 3 and Yiqiao Xing 4 ,*
Abstract
The purpose was to investigate the protective effects of Vitamin C (Vit C) and the regulatory mechanism between Vit C and sirtuin 1 (SIRT1) in PREs during oxidative stress as Vit C and SIRT1 exerted famous effects as antioxidants. We found that moderate Vit C (100 µM) prevented ARPE-19 cells from damages induced by H2O2, including increasing viability, reducing apoptosis, and attenuating intracellular ROS levels. But lower and higher concentration of Vit C had no effects. Further results indicated that Vit C caused the dysregulation of some stress responses factors (SIRT1, p53 and FOXO3) in ARPE-19 cells response to H2O2. Moreover we found that SIRT1 activator resveratrol (SRV) stimulated significantly the protective effects of moderate Vit C, provided the property of antioxidative stress for the lower and higher concentration of Vit C in ARPE-19 cells as well. Consistently, nicotinamide (NA) relieved the protective functions of moderate Vit C. Interestingly, data also revealed the dysregulation of p53 and FOXO3 was dependent on the regulation of SIRT1 rather than Vit C. Summarily, the protective effect of Vit C against oxidative stress was involved in regulation of SIRT1. It suggested that combined application of Vit C and RSV might be a promising therapeutic method for AMD.Vitamin C Protected Human Retinal Pigmented Epithelium from Oxidant Injury Depending on Regulating SIRT1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4132313/
