在若干种生物中，限制饮食已被发现能延长寿命，但这是以降低生殖力为代价的。人们一般认为，这是竞争有限资源的一个例子，因为在这个过程中营养从生殖被重新分配到身体维持。
现在，Grandison等人发现，对果蝇来说，限制饮食不会诱导营养重新分配，因为限制寿命和生殖力的是不同氨基酸。他们发现，长寿命果蝇的生殖力只需通过添加蛋氨酸就可得以挽救。因此，在没有饮食限制时，通过调整饮食中氨基酸的比例，长寿命和高生殖力就可以同时实现。这些发现意味着，人类也许能通过调整饮食营养成分来获得减少食物摄取量的好处，而不会产生副作用。（生物谷Bioon.com）
热量摄入与寿命：
Nature：蛔虫的启示 少食而长寿
FASEB：长寿老鼠揭开人类衰老的秘密
Nature：反复禁食可延长线虫寿命
Science：蠕虫燃烧油脂以增长寿命
Molecular Cell：能延长寿命和降低胆固醇的基因
Science：敲除一种激酶基因限制热量摄入可延长寿命
长寿基因：
Hum. Reprod.：父本基因或可缩短子代寿命
HMG：发现两个与长寿相关基因
Genes and Development：发现哺乳动物新长寿基因Cisd2
PNAS：FOXO3A基因变异的人更加长寿
生物谷推荐原始出处：
Nature 462, 1061-1064 (24 December 2009) | doi:10.1038/nature08619
Amino-acid imbalance explains extension of lifespan by dietary restriction in Drosophila
Richard C. Grandison1,2, Matthew D. W. Piper1,2 & Linda Partridge1
1 Institute of Healthy Ageing, Department of Genetics Evolution and Environment, University College London, Gower St, London WC1E 6BT, UK
2 These authors contributed equally to this work.
3 Correspondence to: Linda Partridge1 Correspondence and requests for materials should be addressed to L.P.
Dietary restriction extends healthy lifespan in diverse organisms and reduces fecundity1, 2. It is widely assumed to induce adaptive reallocation of nutrients from reproduction to somatic maintenance, aiding survival of food shortages in nature3, 4, 5, 6. If this were the case, long life under dietary restriction and high fecundity under full feeding would be mutually exclusive, through competition for the same limiting nutrients. Here we report a test of this idea in which we identified the nutrients producing the responses of lifespan and fecundity to dietary restriction in Drosophila. Adding essential amino acids to the dietary restriction condition increased fecundity and decreased lifespan, similar to the effects of full feeding, with other nutrients having little or no effect. However, methionine alone was necessary and sufficient to increase fecundity as much as did full feeding, but without reducing lifespan. Reallocation of nutrients therefore does not explain the responses to dietary restriction. Lifespan was decreased by the addition of amino acids, with an interaction between methionine and other essential amino acids having a key role. Hence, an imbalance in dietary amino acids away from the ratio optimal for reproduction shortens lifespan during full feeding and limits fecundity during dietary restriction. Reduced activity of the insulin/insulin-like growth factor signalling pathway extends lifespan in diverse organisms7, and we find that it also protects against the shortening of lifespan with full feeding. In other organisms, including mammals, it may be possible to obtain the benefits to lifespan of dietary restriction without incurring a reduction in fecundity, through a suitable balance of nutrients in the diet.
