you live in an entropic universe. everything is killing you at all times.
its extremely difficult to explain the nuances of why 'everything is bad for you.' apples are bad for you if your diet was 100% apples, as you would have a very high glycemic load, very low amount of usable proteins, inflammatory, no fats, and likely quickly arrive at some sort of deficiency. hell, if your diet is 100% carrots, you will turn orange. too much milk creates way too much lactic acid, hard on your body (also produces excess mucous, which feeds cancer cells). red meat is an excellent protein source, and is typically packed with vitamins and minerals, however, its extremely easy to eat too much red meat and send your saturated fat and cholesterol levels through the roof. im just rattling off random things here. the point is to learn how to balance.
oh, and you have cancer. everyone does. at all times. the question is, how much? and conversely, how are the antioxidant levels of your body, which are used to destroy randomly roaming particles/atoms that bust apart your mitochondrial dna? or worse, how many elemts are you putting into your body that results in molecules/particles that damage your cells?
basically, if youre looking for something that is 100% never bad for you, youre in the wrong universe. even the sun, which we need to survive, kills us. so does oxygen. how bout that?
growth hormones, antibiotics, non digestible agents in food, imitation sugars, neurotoxic zero carb replacements, carcinogenic cooking techniques, genetically modified foods, preservatives, etc, these things are very difficult to avoid in a modern society. all you can do is read up on them, know how they affect your physiology, and know how to moderate your daily diet to guide your body into a state of balance.
