title: Parsing the life-shortening effects of dietary protein: effects of individual amino acids.
abstract: High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins; (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves; (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins; and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome; surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan.
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France sarganda@bu.edu.|Department of Biology, Boston University, Boston, MA, USA.
authors.forename: Sara
authors.identifier: 0000-0002-9875-2379
authors.initials: S
authors.lastname: Arganda
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Sofia
authors.initials: S
authors.lastname: Bouchebti
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Bazazi
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Le Hesran
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Puga
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Latil
authors.affiliation: School of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia.|Charles Perkins Centre, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Simpson
authors.affiliation: Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France.
authors.forename: Audrey
authors.identifier: 0000-0002-1377-3550
authors.initials: A
authors.lastname: Dussutour
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001000:Ants / Q000502:physiology*; D004032:Diet; D004044:Dietary Proteins / Q000737:chemistry*; D008136:Longevity
chemical_list: D000596:Amino Acids; D004044:Dietary Proteins
keywords: argentine ants; free amino acids; lifespan; nutrition; protein