These two look interesting:
Protein Supplementation Increases Muscle Mass Gain During Prolonged Resistance-Type Exercise Training in Frail Elderly People: A Randomized, Double-Blind, Placebo-Controlled Trial
Old people need to train AND adding some additional protein helps.....
But they need to KEEP OFF STATINS.
Effect of a high dose of simvastatin on muscle mitochondrial metabolism and calcium signaling in healthy volunteers.