Soy Protein May Reduce Breakdown of Muscle Protein
TOKUSHIMA, Japan--Soy protein may prevent exercise-induced protein degradation in skeletal muscle, according to Japanese researchers in the June issue of Nutrition (18, 6:490-5, 2002) (www.sciencedirect.com). Researchers fed rats either a 20-percent casein diet (the control) or a 20-percent soy protein isolate diet, and then had them run at 80 kg/m on a treadmill. Rats on the soy diet experienced a suppressed breakdown of the muscle enzymes calpain and creatine kinase. The soy diet also had an inhibitory effect on myosin degradation, which affects the protein responsible for the elastic and contractile properties of muscle.