Age-related effects of vegetarian diet on protein and amino acid bioavailability – VegAA

Health, environmental and animal welfare concerns have led to a recent reduction of animal products intake. Public health authorities also recommend transitioning towards more sustainable, plant-based diets. While animal proteins are known as good quality proteins with high digestibility, plant proteins are generally considered of lower nutritional values. Plant proteins come with high amount of vitamins and minerals, but also with dietary fibers and anti-nutritional factors, which are known to decrease digestibility acutely. However, the long-term synergetic effects of plant-based foods on adaptation of intestinal functions and protein digestive capacity remain mainly unexplored. In the context of the nutritional transition, a global approach is necessary to understand the effects of the different components of the diet on digestion. This is of particular importance for population with specific needs such as elderly, for which protein requirements are increased and intake usually decreased. Hence, VEGAA project aims at better understanding the influence of a diet rich in plant-based foods on amino acid bioavailability of vegetable proteins throughout adult life, using innovative isotopic tracer techniques. First, we will explore the age-related acute and chronic effects of a diet rich in plant-based foods on amino acid bioavailability, protein metabolism and digestion physiology in a preclinical study. Second, thanks to the recently developed dual isotope method, we will determine amino acid bioavailability changes in young or old adults consuming a vegetarian or omnivorous diet. Overall, VEGAA project will provide important knowledge on plant protein digestibility and adaptive mechanisms that might occur during a long-term change in protein source and as a function of age. Ultimately, VEGAA results will help to estimate protein and amino acid adequacy in the context of plant-based diets to promote healthy aging.