Studies have shown that individuals that eat red or processed meat have a higher risk of developing breast cancer, prostate cancer, and pancreatic cancer.[39] This may be partially explained by the presence of carcinogens in food cooked at high temperatures.[40] Several risk factors for the development of colorectal cancer include high intake of fat, alcohol, red and processed meats, obesity, and lack of physical exercise.[41] A high-salt diet is linked to gastric cancer. Aflatoxin B1, a frequent food contaminate, is associated with liver cancer. Betel nut chewing has been shown to cause oral cancers.[42]