Hi Susie...I was a serious distance runner for years, but gradually my knees were so painful I had to give up. Even walking was painful and I feared I would need knee reconstruction.
This happened to coincide with our daughter being sick and though I thought we ate well at the time (and compared to most we did!), the truth was otherwise.
Anyway, I threw out all processed food and cooked everything from scratch...difficult because I was teaching full time as well.
Within a few weeks I realized my knee pain had completely gone. It has never returned.
I also had disc injury from a car crash, and used to have physio regularly, but with appropriate stretching I now rarely suffer referred pain.
I think we all need to take charge of our own bodies.