Smoking is harmful to health. As we all know, smoking has the following eleven main crimes: loose and dull skin, easy to suffer from eye diseases, easy to lose teeth, wrinkled lips, less and less hair, easy to suffer from breast cancer, easy to suffer from psoriasis, loose and fragile bones, men's failure to relieve female infertility, abnormal blood pressure and heart, and damage to endocrine system.
Carcinogenesis:
People have realized that smoking can cause cancer. Epidemiological investigation shows that smoking is one of the important pathogenic factors of lung cancer, especially squamous cell carcinoma and small cell undifferentiated carcinoma. The risk of lung cancer of smokers is 13 times that of non-smokers. If you smoke more than 35 cigarettes a day, your risk is 45 times that of non-smokers.
The mortality rate of lung cancer in smokers is 10 ~ 13 times higher than that in non-smokers. About 85% of lung cancer deaths are caused by smoking. If smokers are exposed to chemical carcinogens (such as asbestos, nickel, uranium and arsenic, etc. ), the risk of lung cancer will be higher. PAHs in tobacco smoke are cytotoxic and mutagenic only after being metabolized by PAH hydroxylase, and the concentration of this hydroxylase in smokers is higher than that in non-smokers.
Smoking will reduce the activity of natural killer cells, thus weakening the body's function of monitoring, killing and clearing tumor cells, which further explains that smoking is a high risk factor for many cancers. The incidence of laryngeal cancer in smokers is ten times higher than that in non-smokers. The incidence of bladder cancer increased by 3 times, which may be related to β -naphthylamine in smoke.
In addition, smoking is also related to the occurrence of lip cancer, tongue cancer, oral cancer, esophageal cancer, gastric cancer, colon cancer, pancreatic cancer, renal cancer and cervical cancer. Clinical research and animal experiments show that carcinogens in smoke can also affect the fetus through the placenta, leading to a significant increase in the incidence of cancer in its offspring.
Effects on digestive tract:
Smoking can increase gastric acid secretion, which is generally 965438 0.5% higher than that of non-smokers, and can inhibit the secretion of sodium bicarbonate by pancreas, thus increasing duodenal acid load and inducing ulcer. Nicotine in tobacco can reduce the tension of pyloric sphincter, make bile easy to reflux, thus weaken the defense factors of gastric and duodenal mucosa, promote chronic inflammation and ulcer, and delay the healing of original ulcer. In addition, smoking can reduce the tension of lower esophageal sphincter and easily cause reflux esophagitis.