Sies Helmut
Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
J Nutr. 2007 Jun;137(6):1493-5. doi: 10.1093/jn/137.6.1493.
In this contribution, I discuss the applicability of total antioxidant capacity (TAC) data obtained from plasma to human health issues and the use of TAC data for dietary items in epidemiological applications. Against the background of knowledge that major antioxidant defense is enzymatic, the use of the term "total" is not appropriate. Because dietary phytochemicals undergo uptake and metabolism, extrapolation to health effects requires direct molecular information, not a global parameter that uses an arbitrarily selected prooxidant source. Suitable alternatives are given in measuring functional biomarkers (surrogate endpoints). Although using TAC may be helpful in comparing different food items, the extrapolation to their contribution of antioxidant defense in vivo and, further, to health issues, should be discouraged, with the possible exception of the gastrointestinal tract. This is of particular importance because dietary phytochemicals and other small molecules have nonantioxidant activities. Direct assay of urate, ascorbate, and tocopherol, the major small-molecule contributors to TAC, is recommended.
在本论文中，我讨论了从血浆中获得的总抗氧化能力（TAC）数据在人类健康问题中的适用性，以及TAC数据在流行病学应用中用于膳食项目的情况。在主要抗氧化防御是酶促反应这一知识背景下，使用“总”这个术语并不恰当。由于膳食植物化学物质会经历吸收和代谢过程，因此推断其对健康的影响需要直接的分子信息，而不是使用任意选定的促氧化剂来源的全局参数。在测量功能性生物标志物（替代终点）方面有合适的替代方法。尽管使用TAC可能有助于比较不同的食物项目，但除了胃肠道可能的例外情况外，不鼓励将其外推至它们在体内抗氧化防御中的贡献以及进一步外推至健康问题。这一点尤为重要，因为膳食植物化学物质和其他小分子具有非抗氧化活性。建议直接测定尿酸、抗坏血酸和生育酚，它们是TAC的主要小分子贡献者。
