High protein vegan or omnivorous diets support comparable myofibrillar protein synthesis rates and skeletal muscle hypertrophy in young adults
Although recent dietary guidelines recommend consumption of more plant-based foods, existing literature suggests that plant based proteins may be inferior to animal derived proteins. However, little work has been done to compare the effectiveness of plant derived proteins to animal-derived proteins to support resistance training when dietary protein levels are elevated. These were the conditions used in a study conducted by Monteyne and colleagues and they report their results in the June 2023 issue of The Journal of Nutrition.
During phase 1, 16 healthy adults (8 males, 23 years old, BMI = 23) consumed a high protein (1.8 g.kg bm-1.d-1) diet derived from either non-animal protein (VEG1) or omnivorous (OMNI1) sources while performing daily unilateral leg exercises. Myofibrillar protein synthesis rates were determined at rest and after exercise. Muscle fiber cross-sectional area (CSA), whole-body lean mass, thigh muscle volume, muscle strength, and muscle function were determined pre, after 2 and 5 weeks, and postintervention in phase 2. Participants were 22 healthy young adults (11 males, 24 years old, BMI = 23) that completed 10 weeks of a high volume, progressive resistance exercise program and consumed a high protein (~2 g.kg bm-1.d-1) vegan (VEG2) or omnivorous (OMNI2) diet.
There were no differences in the daily myofibrillar protein synthesis rates between the high protein VEG1 and OMNI1 diets, but rates were 12% higher in the exercised leg. Lean mass, thigh muscle volume, and muscle fiber cross-sectional area were increased by exercise for both the VEG2 and OMNI2 diets, with resulting strength increases for multiple muscle groups. The authors concluded that omnivorous and vegan diets can support comparable rested and exercise induced myofibrillar protein synthesis rates, and adaptation to high-volume resistance training in young individuals with an overall high protein intake.
In an editorial, Hannaian and Churchward-Venne describe the prior literature suggesting that protein derived from plant foods was inferior to those derived from animal sources. They provide an overview of the work by Hannaian and colleagues, and note that the habitual and intervention protein levels consumed by the participants were high and suggest that fact probably explains why there were no differences between the responses generated by the dietary interventions. They conclude by suggesting animal derived proteins are not obligatory to support skeletal muscle anabolism in young adults consuming a high-protein diet.
Monteyne AJ, Coelho MOC, Murton AJ, Abdelrahman DR, Blackwell JR, Koscien CP, et al. Vegan and omnivorous high protein diets support comparable daily myofibrillar protein synthesis rates and skeletal muscle hypertrophy in young adults. Journal of Nutrition, Volume 153, Issue 6, June 2023, Pages 1680-1695, doi.org/10.1016/j.tjnut.2023.02.023.
Hannaian SJ, Churchward-Venne TA. Meatless muscle growth: Building muscle size and strength on a mycoprotein-rich vegan diet. Journal of Nutrition, Volume 153, Issue 6, June 2023, Pages 1665-1667, doi.org/10.1016/j.tjnut.2023.04.011.
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