The outcry from the establishment who represent your version of science-proven therapies is very germaine to this forum in general and your post in particular, because you headline stated that fraud attached itself to "unproven therapies" of which, by implication, you made Gerson's treatment protocol out to be. My point is that, according to scientifically proven records and to statements from within the scientifically proven community, there was more quackery and fraud attached to mainstream medicine.
The problem I have with your "science" is that what you see as science has been bought and sold to the highest bidder - mainstream managed illness germ theory medicine and the evil empire of world pharma. I am a great fan of true science, meaning unbiased observable and provable science, and have been all my life. That is why I had completed college calculus and college chemistry before graduating from high school.
The corrupted studies of research that consistently delivers results favorable to those who fund the studies is not science. That is fraud - a topic of your original post. If true science held sway, it would be natural alternatives, diet and nutrition that held sway instead of the corrupt and side effect laden drugs and the ineffective treatment of symptoms we are subjected to.