Dietary restriction and lifespan: adaptive reallocation or somatic sacrifice?. (3rd May 2022)

• Record Type: Journal Article
• Authors: Piper, Matthew D. W.; Zanco, Brooke; Sgrò, Carla M.; Adler, Margo I.; Mirth, Christen K.; Bonduriansky, Russell
• Is Part Of: FEBS journal. Volume 290:Number 7(2023)
• Page Start: 1725
• Page End: 1734
• Publication Date: 2022-05-03
• Subjects: ageing -- dietary restriction -- Drosophila melanogaster -- micronutrients -- sterols; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.16463
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : Reducing overall food intake, or lowering the proportion of protein relative to other macronutrients, can extend the lifespan of diverse organisms. A number of mechanistic theories have been developed to explain this phenomenon, mostly assuming that the molecules connecting diet to lifespan are evolutionarily conserved. A recent study using Drosophila melanogaster females has pinpointed a single essential micronutrient that can explain how lifespan is changed by dietary restriction. Here, we propose a likely mechanism for this observation, which involves a trade‐off between lifespan and reproduction, but in a manner that is conditional on the dietary supply of an essential micronutrient – a sterol. Importantly, these observations argue against previous evolutionary theories that rely on constitutive resource reallocation or damage directly inflicted by reproduction. Instead, they are compatible with a model in which the inverse relationship between lifespan and food level is caused by the consumer suffering from varying degrees of malnutrition when maintained on lab food. The data also indicate that animals on different lab foods may suffer from different nutritional imbalances and that the mechanisms by which dietary restriction benefits the lifespan of different species may vary. This means that translating the mechanistic findings from lab animals to humans will not be simple and should be interpreted in light of the range of challenges that have shaped each organism's lifespan in the wild and the composition of the natural diets upon which they would feed. Abstract : Mild dietary restriction can extend lifespan in diverse organisms. We describe a mechanism for Drosophila melanogaster in which mothers on low food diets are longer lived because they commit less to reproduction and so avoid the costs of dietary micronutrient limitations that occur in their natural diets. In detailing this mechanism, we also propose that different dietary restriction treatments are likely to differ in the way they extend life.