Unfortunately, my skin type is of irish descent. I grew up and still live in a very sunny region. I doubt their exists any kind of elusive diet fix for genetic predisposition to non melanoma skin cancers. Not to mention i can't undo decades of damage from intense summer days of my childhood or the toxic sludge called sunscreen my mom use to slather on me constantly as a child during the 80s. As far as eating a healthy diet, my diet is pretty good, as far as reducing toxins and things like radiation, unless you have a time machine and can go back in time to pre industrialization era it's pretty much impossible living in the modern world/society to significantly reduce exposure to chemicals/pollution/radiation ect,.
My dad eats one of the healthiest diets of anyone I've ever met, and is fit and young looking for someone in his 60s, but having skin problems like bcc has always been a issue with him. He was impressed by my Iodine results though. :)