I should have qualified my concerns and theories as being limited just to head and neck cancers. I am questioning the common advice about diet in relationship to the subset of cancer this forum focuses on. Does Smoking causing cancer for most people, that's the impression I got from this NCI web site
NCI & smoking/cancer and the printed warnings on the cigarette packages.
I don't think there is any serious doubt that HPV and smoking cause the majority of head & neck cancers, which of course is my focus. There may be valid studies out there that have been validated and show some efficacy of diet and nutrition in not getting head and neck cancer, but I am unaware of them. I have read lots of valid studies showing that diet and nutrition can indeed prevent heart condition and diabetes, plus of course obesity.