I just saw an Rheumatologist a month ago for the pain in my right knee. He had blood work done and a scan done on my vertebra. The pain is caused by osteoarthritis and he gave me a prescription for pain meds. I tore it up. I don't take medication.
I went to see a friend of mine who has a phd in nutrition about my problem. She said never eat "nightshade" vegetables, which are peppers, potatoes, tomatoes, eggplant, curry, chili & paprika, and to take Omega three times a day. She said these "nightshade" vegetables block the bodies ability to stop pain.
Anyway, here are a couple of articles I found too.
Nightshade Vegetables: Should People With Arthritis Avoid Nightshade Foods? Nightshade Vegetables and Arthritis