A Friend Of Mine Has Prostate Cancer And Is Being

A friend of mine has prostate cancer and is being treated with radiation. Age 74. The cancer hasn't spread but has tentacles. The doctor gave him a list of foods NOT to eat and they are all food that are very healthy. They say he has to much gas when they do radiation. Doesn't this seem like the wrong thing to do. I think he should eat healthy but take gas-x or beano etc. Can you give him some advice? Thank you!!!