How about looking at he overall picture of his health? What is his diet? How is his nutrition? What are you feeding the body so that it can repair? What are you feeding the body for energy? How much artificial chemicals and preservatives is his system having to fight during digestion and absorption? I have helped clients see great improvements in their health simply by eliminating foods that are difficult to digest and hinder absorption. I work with guys that are over 60 and can workout with a heart rate
over 180. It is because they have a base of nutrition that allows them to do so.
How much time has your doctor spent on his diet and nutrition? How much training has your doctor had in that area?
If you are interested I can give you some simple changes that should make a big difference.