School of Life Sciences, Kingston University, Penrhyn Road, Kingston, London KT1 2EE, UK.
Immun Ageing. 2008 May 20;5:3. doi: 10.1186/1742-4933-5-3.
Numerous theories of ageing exist and many are interconnected when viewed through a modern integrative biology perspective. Diet provides a link to a large number of the theories that prevail at the molecular levels. In particular, metal ions form key elements of the radical theory along with having established roles in several age-related neurodegenerative disorders. Lifetime exposure to metals has been linked to ageing by contributions to oxidative stress and neurodegenerative disorders. As many foodstuffs contain high levels and diverse profiles of metals, their cumulative effect on ageing warrants investigation. The cumulative level of concern from environmental exposure can be expressed as a dimensionless index of target hazard quotient (THQ) or for known carcinogens, the target cancer risk (TR). This paper posits that a quantifiable relationship exists between ageing and level of concern resulting from cumulated metal exposure; and that this relationship can be used to develop an ageing-related index of concern from chronic metal ion exposure. As individual differences may facilitate or moderate this cumulated exposure, the potential influence on ageing or on the development of neurodegenerative disorders should be included into the model.
存在许多衰老理论，从现代综合生物学的角度来看，许多理论是相互关联的。饮食为在分子水平上流行的许多理论提供了联系。特别是，金属离子是自由基理论的关键元素，并且在几种与年龄相关的神经退行性疾病中具有确定的作用。由于金属在一生中的暴露会导致氧化应激和神经退行性疾病，因此与衰老有关。由于许多食物都含有高水平和多种金属，因此它们对衰老的累积影响值得研究。环境暴露的累积关注水平可以表示为目标危害商数（THQ）的无量纲指数，或者对于已知的致癌物质，可以表示为目标癌症风险（TR）。本文假设，衰老与由于累积金属暴露而引起的关注程度之间存在可量化的关系；并且可以利用这种关系来开发一种与慢性金属离子暴露有关的衰老相关的关注指数。由于个体差异可能促进或调节这种累积暴露，因此应将其对衰老或神经退行性疾病发展的潜在影响纳入模型。
