Donuel, aging women lose muscle mass faster than men because we lack both estrogen and testosterone. The best preventives are resistance and weight-bearing exercise and, yes, a high-ptotein diet, but there is no magic bullet. Sarcopoenia is in everyone's future if we're lucky enough to live that long.
That said, the greater frequency of falls among old women is due mostly to weakness in the core muscles, which are critical to balance -- when you slip, it's your back and belly muscles that do the most to jerk you upright again.