DeVries' book: "Therapeutic Fasting" is a classic of fasting literature, so a good choice of purchase.
Q. Have I heard of anyone reversing grey hair when they eat more healthily?
A. No. I'm afraid not.
What I do know from my 30 years' study of nutrition is that grey hair can be prevented by an optimum intake of the mineral copper.....about 900mcg per day.
One ounce of cashews contain approx' 630mcg of copper.
I have several grey hairs with some slight thinning on the top of my scalp, but still have a mostly full head of brown hair at the age of 56!!
If we had the cure for baldness we would be rich men, so unfortunately, I don't think one exists.