Author(s): CAMERA, D., AL REFAI, W., COOKE, M., KEENAN, S., Institution: SWINBURNE UNIVERSITY OF TECHNOLOGY, Country: AUSTRALIA, Abstract-ID: 2303

INTRODUCTION:
Appropriate nutritional support is essential to maximize the beneficial effects of exercise training. Protein ingestion can positively regulate expression of genes implicated in skeletal muscle protein turnover and metabolism. However, a limitation to the current knowledge of gene expression responses after exercise with protein intake is that most studies have been confined to the ingestion of free/ intact amino acids and/ or animal-based proteins. In contrast, little is known about changes in gene expression in response to plant-based proteins which is surprising considering the majority of dietary protein intake worldwide is derived from plant-based sources. The primary aim of this study was to compare the effects of either a short-term (i.e., 2-weeks) vegan or omnivorous diet on the expression of select genes implicated in skeletal muscle mitochondrial biogenesis, inflammation, and protein turnover in recreationally active males.
METHODS:
Twenty, recreationally active and otherwise healthy male participants were recruited. A between-subjects design was employed where participants were pair-matched for leg press and extension strength as well as body mass and allocated to either a vegan (n = 10; Age: 25.6 ± 5.2 years; BMI: 25.9 ± 4.8; Leg Press 1-Rep Max: 170.6 ± 61.3 kg; mean ± standard deviation) or omnivorous (n = 10; Age: 26.2 ± 3.9 years; BMI: 25.0 ± 2.1; Leg Press 1-Rep Max: 166.0 ± 71.3 kg; mean ± standard deviation) group. Following preliminary testing, participants consumed a dietary control meal the evening prior to commencing the 14-day diet and exercise intervention period. For this intervention, participants consumed either a vegan diet (54% Carbohydrate, 26% Fat, 19% Protein; 1.6g protein/kg body mass/day) or omnivorous diet (48% Carbohydrate, 32% Fat, 18% Protein; 1.6g protein/kg body mass/day) and undertook six sessions of resistance exercise throughout the 14-day period. Skeletal muscle samples from the vastus lateralis were collected pre-, mid-, and post-intervention.
RESULTS:
Taqman gene expression primers will be used to measure the expression of genes implicated in skeletal muscle mitochondrial biogenesis (PGC-1alpha, Tfam), inflammation (IL-6, TNF-alpha) and protein turnover (MuRF-1, Atrogin-1, Myostatin, IGF-1). The expression of these markers will be analyzed pre-intervention, as well as mid- and post-intervention. Changes in expression will be normalized to GAPDH.
CONCLUSION:
Findings from this work will be the first to report changes in gene expression in human skeletal muscle comparing the short-term effects of either a vegan or omnivorous diet in young, recreationally trained individuals. Such findings will be important to provide a mechanistic basis to physiological adaptation responses with each diet when combined with resistance training. Moreover, this work will advance knowledge of the capacity for vegan diets to mediate changes in gene expression pertinent to skeletal muscle adaptation responses with exercise.