Pharmaceutical companies aren't likely to invest millions studying turmeric, spirulina, chlorella, sunlight, etc. There are credible studies if you intentionally go looking for them, though.
Here are a few that may change your mind: http://jn.nutrition.org/cgi/content/full/137/1/233S http://www.annieappleseedproject.org/lifchancline.html http://bastyrcenter.org/content/view/913/
Surely you must admit that your claim that lifestyle change cannot reduce mortality rate is premature. It's only recently being studied, and with the great early results we will see many more such papers investigating the effects.
My money would be on a combination: Lifestyle change + aggressive supplementation + chemo.
"It just doesn't work" is a statement of fact. I showed you some research that refutes this (lifestyle change alone can cure in certain cases). What more do you need to change your opinion?