Japanese and Australian researchers have recently discovered that smoking a large amount of soy products can reduce the damage of cigarettes to the lungs and reduce the risk of chronic obstructive pulmonary disease, thereby reducing respiratory symptoms such as cough. Researchers believe that a large number of flavonoids in soy products have anti-inflammatory effects, which can slow down the lung inflammation, but more research is needed to confirm the biological mechanism behind it. The soy products that we often touch in our daily life include tofu, dried bean curd, bean sprouts, soy milk, etc. Old smokers can eat more.