Infections

• "Helicobacter pylori" is a bacteria that can infect the stomach and result in ulcers and inflammation, and this chronic inflammation may cause stomach cancer.
  
  

Chemicals

• Cured meats such as ham, bacon and hot dogs contain nitrates and nitrites that can form cancer causing chemicals in the stomach.
  
  

Preserved Foods

• Foods that are preserved by smoking, curing or pickling such as pickled fish or vegetables increase the risk of developing stomach cancer.
  
  

Red Meat

• According to the Mayo Clinic, eating a diet rich in red meat that is cooked by barbecuing to well-done may be a cause of stomach cancer.
  
  

Tobacco

• Smoking or chewing tobacco can inflame the lining of the stomach, which may result in the development of stomach cancer.
  
  

Alcohol

• Excessive drinking over a long duration of time can inflame and damage the lining of the stomach and cause stomach cancer.
  
  

Genetics

• According to the Mayo Clinic, people with a family history of breast cancer involving the BRCA1 and BRCA2 genes and people with blood type A are more likely to develop stomach cancer.