新视点：抗氧化剂可能有损肌肉功能？

 
抗氧化剂有助于消灭人体内的自由基，防止这些有害物质侵袭人体细胞，因而受到越来越多的重视。但美国最新一项研究显示，不恰当地摄入抗氧化剂同样会对人体造成伤害。
 
美国堪萨斯州立大学心肺运动实验室的研究人员长期从事抗氧化剂改善人体活动机能的研究。他们在动物实验中发现，抗氧化剂有时会对人体的肌肉功能造成损伤。
 
研究人员在最新一期《美国生理学和实验生理学杂志》（The American Journal of Physiology and Experimental Physiology）上报告说，抗氧化剂给人体健康带来的好处被夸大了。参与研究的史蒂文·科普说，人体中有些自由基如氢过氧化物对增强血液流动是有益的，但如果抗氧化剂把氢过氧化物或者其他自然生成的血管扩张物质消耗掉，那么人体向肌肉输送氧气的功能就会遭到破坏，使肌肉丧失正常功能。
 
科普指出，目前在商场和超市里到处可以看到广告宣传富含抗氧化剂的食品，其实许多人并不了解抗氧化剂和自由基的平衡实际上是很微妙的，并不是抗氧化剂获取越多越有助于人体健康，要根据个人的身体机能和生理状况摄取这类物质，否则将会适得其反。
 
更多阅读
 
美国堪萨斯州立大学网站相关报道（英文）

这个研究很重要，对抗氧化剂的理解有了新的认识。
Sports Medicine 杂志上也有最新的报道非常精彩的一篇论文。 
                                                                                                                                                                                    

Does antioxidant vi*****in supplementation protect against muscle damage?

McGinley C, Shafat A, Donnelly AE.
Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.

The high forces undergone during repetitive eccentric, or lengthening, contracti***** place skeletal muscle under c*****iderable stress, in particular if unaccustomed. Although muscle is highly adaptive, the resp*****es to stress may not be optimally regulated by the body. Reactive oxygen species (ROS) are one component of the stress resp*****e that may contribute to muscle damage after eccentric exercise. Antioxidants may in turn scavenge ROS, thereby preventing or attenuating muscle damage. The antioxidant vi*****ins C (ascorbic acid) and E (tocopherol) are among the most commonly used sport supplements, and are often taken in large doses by athletes and other sportspers***** because of their potential protective effect against muscle damage. This review assesses studies that have investigated the effects of these two antioxidants, alone or in combination, on muscle damage and oxidative stress. Studies have used a variety of supplementation strategies, with variati***** in dosage, timing and duration of supplementation. Although there is some evidence to show that both antioxidants can reduce indices of oxidative stress, there is little evidence to support a role for vi*****in C and/or vi*****in E in protecting against muscle damage. Indeed, antioxidant supplementation may actually interfere with the cellular signalling functi***** of ROS, thereby adversely affecting muscle performance. Furthermore, recent studies have cast doubt on the benign effects of long-term, high-dosage antioxidant supplementation. High doses of vi*****in E, in particular, may increase all-cause mortality. Although some equivocation remains in the extant literature regarding the beneficial effects of antioxidant vi*****in supplementation on muscle damage, there is little evidence to support such a role. Since the potential for long-term harm does exist, the casual use of high doses of antioxidants by athletes and others should perhaps be curtailed.

Sports Med. 2009;39(12):1011-32.

堪称能令人扭转观念的发现。

 


Handbook of Oxidants and Antioxidants in Exercise

自由基、抗氧化剂等等一直是运动人体科学研究生硕士论文的热点。《运动中的氧化剂和抗氧化剂手册》这本书算是这个领域的巨著了，非常值得阅读。电子版下载地址见下：

http://www.vo2max.com.cn/read.php?tid=6927

其实很多时候人们在夸大某些物质的作用，比如说肉碱,只是在脂肪酸进行B氧化时的一个穿越进入线粒体的载体而已,但市面上很多减肥产品都在夸大其功效,  还有磷酸果糖,只是糖酵解过程的一个限速酶的激活物而已, 人们往往夸大其作用,其实成本很低的个东西,买的很贵.

这种言论很快就会被利用

小弟五年前读书时，恰好做的是抗氧化与氧化的平衡问题，
当年既有很多争论的观点，
所以小弟的观点是不可偏信，要根据自己的情况去思考。
就像去年芬兰的科学家做出了补充维生素的物质对人体有害的结论一样，事实上还没有被完全证明是对的。

学习了一下，但是这种观点.................

谢谢分享，前沿知识，可以对于抗氧化物的作用更客观的认识。

这个研究几乎在各大学术杂志发表了相关的报道。

ACSM's Health & Fitness Journal 最新的一期 May/June 2010 - Volume 14 - Issue 3有文献发表。

Are Antioxidant Supplements Required for Active Adults?

Reports about the dangers of free radicals and their negative impact on human health are common in the news media today. This increased public awareness of the role that free radicals play in human aging and disease has prompted many health-minded individuals to supplement their diet with commercially available antioxidant supplements. It follows that this widespread public interest in antioxidant supplements has motivated supplement suppliers to release an avalanche of antioxidant products into the marketplace. Promotional claims for these products are numerous and include the assertion that antioxidant supplements slow the aging process and decrease the risk of heart disease and cancer. Moreover, some proponents of antioxidant supplementation suggest that exercise training increases the requirements for antioxidants. However, does scientific research support the need for additional antioxidants beyond those contained in a well-balanced diet? This brief article will address this issue by summarizing the current literature on this topic. We begin with an introduction to free radicals and antioxidants.

Are Antioxidant Supplements Required for Active Adults.rar (549 K) 下载次数:1

这个研究很重要，对抗氧化剂的理解有了新的认识。

是否应从补充剂量以及从局部器官的机能与机体稳态考虑，并非凭条件有限的研究简单认为补充有无作用或是否应补充。