Speakman John R, Hambly Catherine
School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland, UK.
J Nutr. 2007 Apr;137(4):1078-86. doi: 10.1093/jn/137.4.1078.
Caloric restriction (CR) is the only experimental nongenetic paradigm known to increase lifespan. It has broad applicability and extends the life of most species through a retardation of aging. There is considerable interest in the use of CR in humans, and animal studies can potentially tell us about the impacts. In this article we highlight some of the things that animal studies can tell us about CR in humans. Rodent studies indicate that the benefits of CR on lifespan extension are related to the extent of restriction. The benefits of CR, however, decline as the age of onset of treatment is delayed. Modeling these impacts suggests that if a 48-y-old man engaged in 30% CR until his normal life expectancy of 78, he might increase his life expectancy by 2.8 y. Exercise and cold exposure induce similar energy deficits, but animals respond to these energy deficits in different ways that have a minor impact on lifespan. Measurements of animal responses when they cease restriction indicate that prolonged CR does not diminish hunger, even though the animals may have been in long-term energy balance. Neuroendocrine profiles support the idea that animals under CR are continuously hungry. The feasibility of restricting intake in humans for many decades without long-term support is questionable. However, what is unclear from animal studies is whether taking drugs that suppress appetite will generate the same impact on longevity or whether the neuroendocrine correlates of hunger play an integral role in mediating CRs effects.
热量限制（CR）是已知的唯一一种能延长寿命的非基因实验范式。它具有广泛的适用性，可通过延缓衰老来延长大多数物种的寿命。人们对在人类中应用热量限制颇感兴趣，动物研究有可能让我们了解其影响。在本文中，我们重点介绍一些动物研究能告诉我们的关于热量限制对人类影响的情况。啮齿动物研究表明，热量限制对延长寿命的益处与限制程度有关。然而，随着开始进行热量限制治疗的年龄推迟，其益处会下降。对这些影响进行建模表明，如果一名48岁的男性进行30%的热量限制直至其正常预期寿命78岁，他的预期寿命可能会延长2.8年。运动和寒冷暴露会导致类似的能量不足，但动物对这些能量不足的反应方式不同，对寿命的影响较小。当动物停止限制时对其反应的测量表明，长期的热量限制并不会减轻饥饿感，即便动物可能一直处于长期能量平衡状态。神经内分泌特征支持这样一种观点，即处于热量限制状态下的动物一直处于饥饿状态。在没有长期支持的情况下，人类持续数十年限制热量摄入的可行性值得怀疑。然而，动物研究尚不清楚的是，服用抑制食欲的药物是否会对寿命产生同样的影响，或者饥饿的神经内分泌关联因素在介导热量限制的作用中是否起着不可或缺的作用。
