It is well known that cigarettes are the most definitive cause of lung cancer. So can food eaten into the digestive tract, without direct contact with the lungs, also cause lung cancer? The answer is yes. Natural foods may seem harmless, but improper methods of cooking food can also lead to lung cancer. For example, cooking methods such as grilling and deep-frying produce polycyclic aromatic hydrocarbons such as benzopyrene, which, among others, has a definite carcinogenic effect, during the production process. Therefore, when cooking for lung cancer patients, try to use cooking methods with less fumes, such as steaming, boiling, boiling and stewing. In addition, car exhaust also contains benzo(a)pyrene, so lung cancer patients should try to reduce staying and exercising on roads with many vehicles for a long time. In addition to marinated, grilled and fried foods and alcohol, which are class 1 carcinogens and can cause cancer, excess red meat, processed meats are class 2A carcinogens, and studies have found that they can increase the risk of many cancers in animals, including lung cancer, but the role in humans is uncertain and it is prudent not to eat them or to eat them sparingly.