At present, scholars from various countries have conducted a lot of researches on malignant tumors and their influencing factors, and it is believed that malignant tumors are caused by the interaction of environmental factors and cytogenetic material, rather than simply by genetic susceptibility. Environmental carcinogenic factors include biological, physical and chemical factors of the natural environment as well as social environmental factors, and most of these carcinogenic factors affect the organism through people’s poor lifestyle, such as smoking, alcohol abuse and unhealthy dietary habits, as well as lack of exercise, except for a small number of people who are exposed to them involuntarily.
It is well known that smoking can increase the risk of lung cancer. In addition to lung cancer, smoking is also associated with the incidence and death of many cancers, such as liver, esophagus, stomach, pancreatic and bladder cancers. Data show that after 15 years of successful smoking cessation, the risk of lung cancer decreases to normal levels.
Alcohol abuse is also associated with many diseases, such as affecting liver function, blood sugar, blood lipids and blood pressure, as well as being a risk factor for the development of liver and stomach cancer. In addition to directly damaging liver cells, alcohol can increase the risk of hepatitis B virus infection and increase the reproduction of hepatitis C virus, further increasing the risk of liver cancer.
Bad dietary habits can increase the risk of digestive tumors, such as eating pickled foods, irregular diet, eating moldy foods, hot food, high salt diet, and eating pickled vegetables. The nitroso compounds in pickled and moldy foods have strong carcinogenic effects; long-term consumption of hot food can cause damage to the mucous membrane of the digestive tract, which can increase the risk of tumor development and cause esophageal cancer and stomach cancer, and a high-calorie diet may increase the risk of intestinal cancer. In addition, factors such as high fat diet, low vegetable intake, and high body mass can also increase the incidence of breast cancer in women.
Many studies have proven that regular and frequent physical activity can reduce the risk of many diseases, especially moderate amount of exercise (more than 2 hours of exercise per week) can reduce the risk of tumors, such as breast cancer, lung cancer, genitourinary system cancer, and digestive system cancer (e.g. rectal cancer).