Last time I saw this diet being promoted for cancer prevention and/or treatment, it was based on diets given to primates in captivity. It was promoted by Dr. Ax

Last time I saw this diet being promoted for cancer prevention and/or treatment, it was based on diets given to primates in captivity. It was promoted by Dr. Axe types, which leads me to believe it isn't exactly good science. I'd genuinely love to be wrong, because if it actually worked, that would be great. I haven't seen evidence to believe it, though. What evidence do you have for the claim that such a diet would work against cancer?