A couple of years ago my friend suffered from really bad skin. Then again, she ate a few sweets here and there and drank and ate food containing dairy. She suffered with bad skin for years. She went to all the 'claimed' best skin doctors to provide special creams for her. None of it really made much difference.
I suggested doing a juice fast indefinately. I did a Water Fast while she only drank blended mixed fruits. 2 days later, her skin was better than it had been in years. Unfortunately she gave up after so we never got to see what more the juice could have done for her.