After a cancer diagnosis, the dinner table suddenly gets complicated. A side dish you ate yesterday without a second thought now makes your hand hesitate. And before long you find yourself poring over those "bad foods for cancer" lists that circulate online and in patient groups, only to feel even heavier once you actually read them. No red meat, no sugar, cut out dairy too... and pretty soon there's nothing left to eat.
These articles tend to rattle the family doing the caregiving even more than the patient. A recipe someone shared with the best of intentions, "for your mother-in-law to try," can come back to another person as guilt: "So was everything I've been feeding her this whole time poison?" The truth is, fragmentary information from no clear source causes plenty of awkwardness between people. And it's all the more true when the subject is food.
During treatment, what really matters about meals isn't strictly cutting out some single food, but eating enough overall and eating a variety. Chemotherapy or radiation tends to kill your appetite and make you lose weight, and if you fall short on protein during that time, recovery slows and even your next treatment schedule can wobble. So getting a little protein at every meal, even just a bit, from lean meat, fish, eggs, tofu, or beans, is actually the priority. Dropping protein entirely over one line like "meat is bad for cancer" often costs you more than it gains.
Of course, there are things worth steering clear of. When your immune system is low, it makes sense to be careful with raw fish, undercooked food, and unpasteurized milk because of the infection risk. There's no real reason to go out of your way to have alcohol, very salty food, or charred bits either. But this is a different matter from the fear that "a particular food makes cancer grow." It's a question of hygiene and balance, not a question of some banned-food list.
The most reliable thing is to ask the care team or dietitian where you're being treated, rather than some list making the rounds. Even with the same cancer, the stage of treatment and the state of the body differ from person to person, and if your kidneys are weak you may even need to adjust your protein. The answer that fits your body ultimately comes from the people who are seeing you in person. So I hope you won't take it too hard when someone posts something with good intentions, and won't let it sway you too much either.
What's written here is just general information, so please be sure to decide your actual diet in consultation with your own medical team.