The Muscle Protein Synthetic Response to the Ingestion of a Plant-Derived Protein Blend Does Not Differ from an Equivalent Amount of Milk Protein in Healthy Young Males

Background: Plant-derived proteins are considered to have lesser anabolic properties when compared with animal-derived proteins. The attenuated rise in muscle protein synthesis rates following ingestion of plant-derived compared with animal-derived protein has been, at least partly, attributed to deficiencies in specific amino acids such as leucine, lysine, and/or methionine. Combining different plant-derived proteins could provide plant-derived protein blends with a more balanced amino acid profile. Objectives: This study aimed to compare postprandial muscle protein synthesis rates following the ingestion of 30 g milk protein with a 30 g blend combining wheat, corn, and pea protein in healthy young men. Methods: In a randomized, double-blind, parallel-group design, 24 young males (aged 24 +/- 4 y) received a primed continuous L-[ring-C-13(6)]-phenylalanine infusion after which they ingested 30 g milk protein (MILK) or a 30 g plant-derived protein blend combining 15 g wheat, 7.5 g corn, and 7.5 g pea protein (PLANT-BLEND). Blood and muscle biopsies were collected frequently for 5 h to assess postprandial plasma amino acid profiles (secondary outcome) and subsequent muscle protein synthesis rates (primary outcome). Data were analyzed by 2-factor repeated measures ANOVA and 2-samples t tests. Results: MILK increased plasma essential amino acid concentrations more than PLANT-BLEND over the 5 h postprandial period (incremental AUC = 151 +/- 31 compared with 79 +/- 12 mmol.300 min.L-1, respectively; P < 0.001). Ingestion of both MILK and PLANT-BLEND increased myofibrillar protein synthesis rates (P < 0.001), with no significant differences between treatments (0.053 +/- 0.013%/h and 0.064 +/- 0.016%/h, respectively; P = 0.08). Conclusions: Ingestion of 30 g plant-derived protein blend combining wheat-, corn-, and pea-derived protein increases muscle protein synthesis rates in healthy young males. The muscle protein synthetic response to the ingestion of 30 g of this plant-derived protein blend does not differ from the ingestion of an equivalent amount of a high-quality animal-derived protein.