Water Fasting helping healing?

I've been doing a lot of research on Nuroplasticity over the past couple of month's and on the way I came across fasting as a way to heal your immune system as well as helping the brain heal. There is also some indication that it can help repair the cns. The science seems to be solid regarding a three - five day fast eating or drinking nothing but water (obvs check to make sure it's suitable for you). The science is that fasting uses all of the dead or damaged cells as fule and when you start re feeding, stem cells start to kick in you generate new healthy cells. It essentially resets your immune system, which seems to have taken a kicking in withdrawal and tge same process does seem to help the other systems of the body as well as the brain. It's also got the ablity to heal damaged dna.

I've started one and I'm currently on hour 42 out of 72, so more than half way through. I hungry and a bit foggy but otherwise OK. One of the things I have noticed is a week before my period, I get horrible lower back pain which has only just shown up after bw. I had that pain yesterday and well now I don't. I guess the true benefits will show up after re feeding (if there are any for this)

Has any one tried a long water only fast and if so, did it benefit?

I'll keep this updated and let you all know how I go.

If anyone want's to know the basics, the below link is from a professor at John Hopkins University who has been researching this.