Jim, if you like to experiment you may want to see this:

Minding your mitochondria | Dr. Terry Wahls | TEDxIowaCity - YouTube

This is Dr. Terry Wahls video on how she reversed MS with a diet.

I'm on this diet for 4 months. No grains, no sweets, green smoothy in the morning. I wouldn't be able to eat so many leaves, smoothy is disgusting but doable. Red veggies I couldn't do.

Lost 14lbs, no constipation.
My PD didn't reverse. May be it develops slower but how would I know?
Hope this helps,
Jacob