A. Diets are much more complex. Recently a Norwegian study showed that a vegetarian diet was helpful in the treatment of rheumatoid arthritis. It is probably not going to be true for everyone. Certain foods have been shown to be helpful in reducing inflammatory proteins, most notably the fish oils or Omega-3 fatty acids. Omega-3 interferes with prostaglandin synthesis.
Prostaglandins are proteins some of which can cause inflammation.
The use of Omega 3 has been shown to reduce inflammation in rheumatoid arthritis. Overall a healthy diet is always recommended as well as maintaining an ideal body weight. This helps avoid putting more weight and pressure on the knees and hips with standing or walking. By far and away, infection is the most feared complication of a joint replacement. The possibility of blood clots forming after surgery exists and preventative measures need to be instituted.