Every few months, a new "miracle cure" for cancer trends on social media. From superfoods and supplements to extreme diets, the promises are always bold – and almost always misleading. The latest claim suggests that a 21-day water fast can "starve" cancer cells and trigger the body to heal itself. It sounds simple, even empowering: stop eating and your body will do the rest. But biology is rarely that simple. Cancer is not a single disease , and metabolism does not switch neatly between "sick"