According to a recent meta-analysis, soy protein is equally effective as animal protein in building muscle mass and strength. Undertaking resistance exercise is key in increasing muscle strength.
Amongst athletes there exists a common misconception that animal proteins, particularly whey, are more effective than soy protein at building muscle mass and strength. This speculation comes from acute studies which find that whey protein stimulates muscle protein synthesis to a greater extent than plant proteins. However, acute differences in muscle synthesis do not reflect longer term impact on muscle strength.
A recent meta-analysis of nine randomised controlled trials compared the longer-term effects of soy protein versus animal proteins, on muscle mass and strength in combination with resistance exercise. Data from 266 individuals were analysed. The majority were men and age ranged between 18 to 70 years.
All the studies found significant increases in muscle strength and muscle mass in response to resistance training after at least 6 weeks of intervention, irrespective of protein source. There was no difference in muscle strength between individuals supplemented with soy protein or with animal (whey, beef, milk or dairy) protein. The main driver for building muscle strength is the combination of protein intake and resistance training.
The results of this meta-analysis indicate that soy protein supplementation produces similar gains in strength and muscle mass compared to animal protein.
According to Mark Messina, PhD, the lead author of the study, soy protein is a good option for meeting protein needs not only because of its ability to promote gains in muscle mass and strength but also because soy protein modestly lowers blood cholesterol and soyfoods are environmentally friendly.
In conclusion, soyfoods and soy protein are an environmentally friendly and delicious plant-based option for building muscle mass and strength.
Reference: Mark Messina, Heidi Lynch, Jared M. Dickinson, Katharine E. Reed. No Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance Exercise. Int J Sport Nutr Exerc Metab. 2018; 28:674-85.