Influence of Diets with Varying Essential/Nonessential Amino Acid Ratios on Mouse Lifespan

Abstract

An adequate intake of essential (EAA) and non-essential amino acids (NEAA) is crucial to preserve cell integrity and whole-body metabolism. EAA introduced with diet may be insufficient to meet the organismal needs, especially under increased physiological requirements or in pathological conditions, and may condition lifespan. We therefore examined the effects of iso-caloric and providing the same nitrogenous content diets, any diet containing different stoichiometric blends of EAA/NEAA, on mouse lifespan. Three groups of just-weaned male Balb/C mice were fed exclusively with special diets with varying EAA/NEAA ratios, ranging from 100%/0% to 0%/100%. Three additional groups of mice were fed with different diets, two based on casein as alimentary proteins, one providing the said protein, one reproducing the amino acidic composition of casein, and the third one, the control group, was fed by a standard laboratory diet. Mouse lifespan was inversely correlated with the percentage of NEAA introduced with each diet. Either limiting EAA, or exceeding NEAA, induced rapid and permanent structural modifications on muscle and adipose tissue, independently of caloric intake. These changes significantly affected food and water intake, body weight, and lifespan. Dietary intake of varying EAA/NEAA ratios induced changes in several organs and profoundly influenced murine lifespan. The balanced content of EAA provided by dietary proteins should be considered as the preferable means for “optimal” nutrition and the elevated or unbalanced intake of NEAA provided by food proteins may negatively affect the health and lifespan of mice.

Nutrient composition of the Indonesian sago grub (Rhynchophorus bilineatus)

“…The sago grub met the FAO/WHO (1973) requirements of 40% essential amino acids and a 0.60 ratio between essential to non-essential amino acids. In a study on mice by Romano et al (2019), it was concluded that the ratio among EAA and NEAA is the most probable factor responsible for the healthpromoting effects of proteins, and that the higher the ratio (closer to 1 or even greater than 1 if supplemented with additional EAA) in the diet, the more efficient it is to increase the lifespan of people suffering from malnutrition.…”

Amino Acid and Carbohydrate Profiles of <i>Rhynchophorus phoenicis</i> (the Larva of Raffia Palm Weevil)

“…This value is an indication that the larva is a good source of amino acid. In a study on mice by Romano et al [12], it was concluded that the ratio among EAA and NEAA is the most probable factor responsible for the health-promoting effects of proteins, and that the higher the ratio (closer to 1 or even greater than 1 if supplemented with additional EAA) in the diet, the more efficient it is to increase the lifespan of people suffering from malnutrition.…”

Protein Syntheses and Autophagy: In Contrast or in Synchrony?

“…While certain components of aliments positively contribute to protein synthesis [41], autophagy [40], mitochondrial biogenesis, and also reduce renal [37], cardiac and muscular fibrosis and increased life span [26], other components (non essential amino acids: NEAA) acts in an opposite manner, resulting in reduced lifespan [6] not just a question of adequate intake of sufficient amounts of EAA, but of intake relative to NEAA introduction, which, if in excess, blunts EAA effects. Also, not all formulations providing EAA exert the same effects.…”

“…Despite eating up to 60% more food, with quantity to compensate for the lack of quality of AAs, rapid wasting leading to a mortal cachexia occurred in animals fed 30% EAA and 70% NEAA, an amount just 15% less EAA than those provided by the vast majority of alimentary proteins. Animals that had the choice among different pellets, always largely selected the most NEAA-rich, and also the most deadly content [6].…”

“…Indeed, since carbohydrates, lipids and amino acids have similar carbon skeletons, and with the noticeable exception of essential non-saturated fatty acids, sufficient nitrogen amounts can be introduced into mammals metabolism just by amino acids, amino acids provided by food are the most important messengers through which the environment communicates with our body [5]; as well, both oxygen and water should be considered as foods for cells. Therefore, an excess or deficiency of nitrogen in food elicits adaptive mechanisms targeting any tissue or organ and, finally, influencing phenotype and life span [6]. Nutrition also evidently controls the balance between protein synthesis and proteostasis.…”