Please tell me what the latest research says about what kind of diet is beneficial and healthy in the prevention and treatment support of joint degeneration especially in the case of young men with chondromalacia patellae enhanced by running. N-acetylglucosoamine, haylurionic acid and chondroitine sulfate present in common pills - dietary supplements - are they only a placebo or do they actually work? What kind of food should be avoided and what is especially beneficial?