The anabolic properties of a vegan diet later in life

Abstract

Plant-based diets are increasingly recommended. Plant-based foods contain proteins of inferior quality when compared to animal-based foods, due to theirunfavorable essential amino acid compositions and lower protein digestibility.Concurrently, ample consumption of high quality dietary protein is necessary for the maintenance of skeletal muscle later in life. The aim of this dissertation wastherefore to examine the effects of plant-based, i.e. vegan, food intake, in the form of a meal or diet, on skeletal muscle in older individuals in a series of randomized controlled trials. It was shown that the muscle protein synthetic response to the consumption of an omnivorous meal is significantly higher when compared to a vegan meal in healthy older adults. However, when implemented for several days, a highly controlled and well-balanced vegan diet did not compromise muscle protein synthesis rates when compared to an omnivorous diet in healthy older adults. Another study in this dissertation identified that a vegan diet that was self-composed by older individuals, and consumed for several weeks, significantly reduced dietary protein intake and skeletal muscle mass when compared to an omnivorous diet. It was additionally shown that participating in a progressive resistance exercise program while consuming a self-composed vegan diet attenuates losses in skeletal muscle mass induced by a self-composed vegan diet, and increases skeletal muscle strength. Furthermore, another study in this dissertation showed that plant-based meat- and dairy analogues frequently exhibit incomplete essential amino acid profiles, which may compromise adequate protein consumption on a plant-based diet. Collectively, the findings of this dissertation provide insight in the anabolic properties of a vegan diet later in life.