Smoking
Gastric cancer has a considerable propensity for the people who smoke when compared with nonsmokers. Cigarettes and cigar are made up of dried tobacco leaves. Tobacco consists of carcinogens and up to 70 cancer-causing agents harmful to lungs. A cigar is more harmful because it has more nitrogen, which increases the risk of gastric cancer. Smoking weakens the immune system, which means the white blood cells are incapable to fight cancerous cells. Moreover, the poisonous material present in the tobacco can cause permanent changes in DNA.