Diet rich in meat proteins can contribute to colon cancer. Nitrosamines, heterocyclic aromatic amines (HCA), and polycyclic aromatic hydrocarbons (PAH) are compounds exhibiting the documented mutagenic and carcinogenic activity. They commonly appear both in the human environment and in the food products, which are grilled, corned, smoked, and preserved with  nitrogen salts. Those carcinogens can also be formed from their precursors present in the diet or transformed in human colon by intestinal microbiota to their equally harmful derivatives.