Manganese-containing foods do not have anti-cancer effects. The main role of food is to provide energy and nutrition for the body to maintain its normal function. There are many manganese-containing foods, including black sesame, black fungus, hazelnut kernel, soybean, shiitake mushroom, seaweed, lotus seed, tea, etc. Green leafy vegetables are also relatively high in manganese, but the main role of these foods is to provide the body with the required trace elements and energy, and they do not have medicinal value, let alone anticancer effects. However, a reasonable diet can enhance the patient’s physical condition, which is also beneficial to the treatment of cancer patients. To fight against cancer, timely and effective treatment should be carried out, and appropriate treatment methods can be chosen according to the stage of disease and the patient’s physical condition, such as surgery, radiotherapy, chemotherapy, immunotherapy, etc.; one should actively cooperate with the doctor’s treatment in order to achieve the purpose of fighting against cancer.