在若干種生物中,，限制飲食已被發(fā)現(xiàn)能延長(zhǎng)壽命，但這是以降低生殖力為代價(jià)的,。人們一般認(rèn)為,，這是競(jìng)爭(zhēng)有限資源的一個(gè)例子，因?yàn)樵谶@個(gè)過(guò)程中營(yíng)養(yǎng)從生殖被重新分配到身體維持,。

現(xiàn)在,，Grandison等人發(fā)現(xiàn)，對(duì)果蠅來(lái)說(shuō),，限制飲食不會(huì)誘導(dǎo)營(yíng)養(yǎng)重新分配,，因?yàn)橄拗茐勖蜕沉Φ氖遣煌被帷Ｋ麄儼l(fā)現(xiàn),，長(zhǎng)壽命果蠅的生殖力只需通過(guò)添加蛋氨酸就可得以挽救,。因此，在沒(méi)有飲食限制時(shí),，通過(guò)調(diào)整飲食中氨基酸的比例,，長(zhǎng)壽命和高生殖力就可以同時(shí)實(shí)現(xiàn)。這些發(fā)現(xiàn)意味著,，人類也許能通過(guò)調(diào)整飲食營(yíng)養(yǎng)成分來(lái)獲得減少食物攝取量的好處,，而不會(huì)產(chǎn)生副作用。（生物谷Bioon.com）

熱量攝入與壽命：

Nature：蛔蟲(chóng)的啟示 少食而長(zhǎng)壽

FASEB：長(zhǎng)壽老鼠揭開(kāi)人類衰老的秘密

Nature：反復(fù)禁食可延長(zhǎng)線蟲(chóng)壽命

Science：蠕蟲(chóng)燃燒油脂以增長(zhǎng)壽命

Molecular Cell：能延長(zhǎng)壽命和降低膽固醇的基因

Science：敲除一種激酶基因限制熱量攝入可延長(zhǎng)壽命

長(zhǎng)壽基因：

Hum. Reprod.：父本基因或可縮短子代壽命

HMG：發(fā)現(xiàn)兩個(gè)與長(zhǎng)壽相關(guān)基因

Genes and Development：發(fā)現(xiàn)哺乳動(dòng)物新長(zhǎng)壽基因Cisd2

PNAS：FOXO3A基因變異的人更加長(zhǎng)壽

生物谷推薦原始出處：

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.