Rayman Margaret P, Infante Heidi Goenaga, Sargent Mike
Nutritional Sciences Division, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
Br J Nutr. 2008 Aug;100(2):238-53. doi: 10.1017/S0007114508922522. Epub 2008 Mar 18.
There is a growing appreciation that it is not just the total intake of dietary Se that is important to health but that the species of Se ingested may also be important. The present review attempts to catalogue what is known about Se species in foods and supplements and the health effects in which they are implicated. The biosynthetic pathways involved in Se assimilation by plants and the way in which Se species are metabolised in animals are presented in order to give an insight into the species likely to be present in plant and animal foods. Known data on the species of Se in the food chain and in food supplements are tabulated along with their concentrations and the analytical methodology used. The latter is important, since identification that is only based on retention-time matching with authentic standards must be considered as tentative: for evidence of structural confirmation, fragmentation of the molecular ion in addition to MS data is required. Bioavailability, as normally defined, is higher for organic Se species. Health effects, both beneficial and toxic, thought to be associated with specific Se species are described. Potent anti-tumour effects have been attributed to the low-molecular-weight species, Se-methyl-selenocysteine and its gamma-glutamyl-derivative, found in a number of edible plants of the Allium and Brassica families. There remain considerable gaps in our knowledge of the forms of Se that naturally occur in foods. Without adequate knowledge of Se speciation, false conclusions may be drawn when assessing Se requirements for optimal health.
人们越来越认识到，对健康重要的不仅仅是膳食硒的总摄入量，摄入的硒的种类可能也很重要。本综述试图梳理关于食物和补充剂中硒种类及其所涉及的健康影响的已知信息。介绍了植物吸收硒所涉及的生物合成途径以及动物体内硒种类的代谢方式，以便深入了解植物性和动物性食物中可能存在的硒种类。列出了食物链和食品补充剂中硒种类的已知数据，以及它们的浓度和所使用的分析方法。后者很重要，因为仅基于与标准品保留时间匹配的鉴定必须被视为初步的：为了进行结构确认，除了质谱数据外，还需要分子离子的碎片信息。通常定义的有机硒种类的生物利用度更高。描述了被认为与特定硒种类相关的有益和有害健康影响。低分子量的硒甲基硒代半胱氨酸及其γ-谷氨酰衍生物具有强大的抗肿瘤作用，这些物质存在于许多葱属和十字花科可食用植物中。我们对食物中天然存在的硒形态的了解仍然存在很大差距。如果没有足够的硒形态知识，在评估最佳健康所需的硒摄入量时可能会得出错误的结论。
