Cancer of the colon develops from benign adenomas, or polyps, that project into the bowel lumen. Most polyps do not progress to cancer, but a small percentage do. It takes approximately 10 years for an adenoma to become cancer. Certain foods can contribute to the development of colorectal cancer.
Red Meat
Beef, pork, veal and lamb can cause colorectal cancer. According to a study in "Journal of Lipid Research" by Dr. Jason M. Ridlon, a diet high in red meat significantly increases taurine levels in the colon. Taurine, an amino acid in bile, aides digestion, but during metabolism produces hydrogen sulfide, which, even in low concentrations, can be toxic and damage DNA. According to a study published in the journal "Carcinogenesis" by Dr. Amit D. Joshi, consumption of more than three servings of red meat per week leads to an increased risk of colorectal cancer.
Grilled meat, especially when well done, can produce carcinogens called heterocyclic amines, or HCAs. Other toxic substances called polycyclic aromatic hydrocarbons, or PAHs, result when fat drips on charcoals causing smoke that combines with the meat.
Processed Meat
Processed meats include hot dogs, ham and salami. Cooked and processed meat may contain chemicals that can cause cells to become cancerous. According to "Harrison's Principles of Internal Medicine," animal fats in meat may increase anaerobic bacteria in the colon that transform bile acids into carcinogens. For example, anaerobic bacteria break down cholic acid to deoxycholic acid, which triggers gene mutations and causes normal cells to become cancer cells.
Salted and Smoked Fish
A diet high in salted and smoked fish is a potent risk factor for colorectal cancer. Nitrites and other chemicals used in smoked, salted foods are converted to carcinogenic N-nitroso compounds in the colon. According to an article in the journal "Lancet" by Dr. T.J. Key, iron in the colon could increase the formation of cancer-causing chemicals.
References
- "Office Practice of Medicine"; William T. Branch; 2003
- Carcinogeneis: Red meat and poultry intake, polymorphisms in the nucleotide excision repair and mismatch repair pathways and colorectal cancer risk
- "Harrison's Principles of Internal Medicine"; Dennis Kasper, M.D.; 2005
- Journal of Lipid Research: Bile salt biotransformations by human intestinal bacteria
- "Lancet"; The effect of diet on risk of cancer; T.J. Key; 2002
