My oncology dietitian recommended a Mediterranean diet. Once I researched that I found Dr. William Li's book: EAT TO BEAT YOUR DISEASE. I'm now eating ? Stokes purple potatoes as often as I can get them (the true purple potatoes are reputed to kill cancer stem cells), and a number of other things that I have never had before. Matcha green tea is now a staple in my diet. He encourages dark chocolate. I'm allowing myself 2 squares of HU Salty Dark Chocolate per day (currently). It's 70% Cacao and uses coconut sugar instead of cane sugar. (It's too expensive, so I may eliminate it before I really want to!!) Unfortunately, I also have autoimmune diseases, which complicates things for me, so I have eliminated all gluten, and milk products with lactose. (I use ghee or lactose free half and half - also too expensive!!) The Mediterranean diet also helps the inflammatory issues associated with the autoimmune diseases.
Best wishes!!