Smoking
Compared to nonsmokers, smokers have a significantly increased risk of developing gastric cancer. Cigarettes and cigars are manufactured from tobacco leaves that have been dried. Tobacco contains carcinogens and up to 70 lung-damaging cancer-causing agents. Cigars are more hazardous because they contain more nitrogen, which increases the risk of developing stomach cancer. Because smoking diminishes the immune system, white blood cells are unable to combat cancerous cells. Moreover, the toxic substances present in tobacco can cause persistent DNA mutations.
