Potato Protein Stimulates Muscle Protein Synthesis At Rest And With Resistance Exercise

Abstract

Skeletal muscle protein synthesis (MPS) is increased in response to amino acid feeding and to resistance exercise (RE) where RE enhances MPS above feeding alone. The use of vegetable based proteins have increased in popularity, however many vegetable based protein sources are of lower protein quality. Potato protein (PP) is a complete protein and has the highest protein quality score of any vegetable protein, however, its efficacy in stimulating MPS beyond the acute setting has yet to be determined. PURPOSE: To determine the effects of PP on MPS with and without RE in healthy young women. METHODS: In a single blind, parallel-group design, twenty-four healthy younger women (21 ± 3 years, n = 12/group) were assigned to consume either 25 g of PP twice daily or a non-protein-containing control (CON). Participants consumed a fully controlled diet for 3 weeks (0.8 g/kg/day CON, 1.6 g/kg/day PP), with non-supplemental protein comprising 51 ± 3% of total protein intake in the PP group. One leg of each participant was randomly allocated to perform RE (Exercise) while the other leg served as a rested control (Rest). RE was performed thrice weekly at ~30% of 1RM (20-25 reps) for 3 sets until volitional fatigue on the leg extension and leg press machines. Myofibrillar MPS was measured at baseline, following supplementation, and at supplementation+RE via the deuterated water method. RESULTS: PP ingestion increased MPS by 0.14 ± 0.09 %/d at Rest and by 0.32 ± 0.14 %/d in Exercise (p = 0.008) while MPS was elevated only in Exercise with CON 0.20 ± 0.11 %/d but was not different from Baseline 0.01 ± 0.04. CONCLUSIONS: Consuming PP in addition to a habitual diet increased rates of MPS at rest and there was a further increase with RE. PP may serve as a high quality, vegetable-based protein supplement to augment muscle protein anabolism in healthy young women. Support by The Alliance for Potato Research & Education