Plant-based food patterns to stimulate muscle protein synthesis and support muscle mass in humans: a narrative review

Abstract

The interest in a diet with a higher proportion of plant-based foods to animal-based foods is a global food pattern trend. However, there are concerns regarding adopting plants as the main dietary protein source to support muscle protein synthesis and muscle mass. These concerns are centred on three issues: lower protein bioavailability due to antinutritional compounds in plants, lower per-serve scores of protein at similar energy intake, and amino acid scores of plants being lower than optimal. We aimed here to synthesize and discuss evidence around plant protein in human nutrition focusing on the capacity of these proteins to stimulate muscle protein synthesis as a key part of gaining or maintaining muscle mass. In this review, we address the issues of plant protein quality and provide evidence for how plant proteins can be made more effective to stimulate muscle protein synthesis and support muscle mass in partial or total replacement of consumption of products of animal origin. 
 
 Novelty: 
 ● Plant proteins are known, in general, to have lower protein quality scores than animal proteins, and this may have important implications, especially for those aiming to increase their skeletal muscle mass through exercise.
 ● A plant-based diet has been postulated to have lower protein quality limiting MPS responses and potentially compromising exercise-induced gains in muscle mass.
 ● Current evidence shows that plant proteins can stimulate MPS, as can whole foods, especially when combining food groups, increasing portion sizes, and optimizing amino acid bioavailability through processing or common preparation methods.

Going Vegan for the Gain: A Cross-Sectional Study of Vegan Diets in Bodybuilders during Different Preparation Phases

“…A properly designed vegan diet seems to be able to meet the protein needs of an endurance athlete via whole foods alone; however, this may not be ideal for maximising muscle growth, as the protein demands for these objectives are higher [ 5 , 7 ]. Indeed, plant protein quality has been reported to likely limit the stimulation of muscle protein synthesis and, subsequently, the gains in muscle mass [ 10 , 11 ]. In competitive bodybuilding, athletes are judged on their aesthetics: muscle size, muscular proportions, and conditioning (the absence of body fat).…”

Pflanzliche Ernährung und ausreichende Proteinzufuhr für ein gesundes Altern

“…Es wird deutlich, dass eine ausreichende Proteinversorgung für den Erhalt der Muskelgesundheit im Alter essenziell ist. Entscheidend sind dabei nicht nur die Proteinmenge, sondern auch die Proteinqualität [17,18]. Pflanzliche Proteine besitzen generell eine niedrigere Proteinqualität und damit einhergehend geringere anabole Wirkung, die anhand der Verdaulichkeit und Resorption sowie Aminosäurezusammensetzung definiert wird [17,18].…”

“…Entscheidend sind dabei nicht nur die Proteinmenge, sondern auch die Proteinqualität [17,18]. Pflanzliche Proteine besitzen generell eine niedrigere Proteinqualität und damit einhergehend geringere anabole Wirkung, die anhand der Verdaulichkeit und Resorption sowie Aminosäurezusammensetzung definiert wird [17,18]. Pflanzliche Proteine weisen, bis auf wenige Ausnahmen, einen niedrigeren Gehalt essenzieller Aminosäuren auf [18].…”

“…Lebensmittel mit der höchsten Proteinqualität umfassen demnach Eier, Milch(-produkte), (Rind-)Fleisch und Soja [18]. Pseudogetreide wie Quinoa, Amaranth und Buchweizen weisen einen relativ hohen Anteil essenzieller Aminosäuren auf und besitzen damit zumindest theoretisch eine ähnlich hohe Proteinqualität vergleichbar zu Mais oder Bohnen [17,18]. Allerdings fehlen bislang Untersuchungen, um ihre Relevanz in Bezug auf die Muskelproteinsynthese, insbesondere im höheren Alter, zu bewerten.…”

Contribution of Proteins to the Latin American Diet: Results of the ELANS Study

“…While the evidence is strong regarding the role of dietary protein in maintaining health across the lifespan, specific qualities of proteins from different dietary sources are not yet fully understood or agreed upon [ 2 , 11 , 12 ]. Plant proteins, when compared with animal proteins, have recently attracted considerable attention in terms of healthiness, affordability, and production sustainability [ 11 , 12 , 13 , 14 , 15 , 16 ]. It is thus important to understand patterns of protein intake (amounts, sources, and processing) in populations of Latin America.…”