Cooking meat at high temperatures produces heterocyclic amines and polycyclic aromatic hydrocarbons.
Processed meats contain N-nitroso compounds.
Meat intake may increase cancer risk as heterocyclic amines, polycyclic aromatic hydrocarbons, and N-nitroso compounds are carcinogenic in animal models.
Dr Rashmi Sinha and colleagues investigated meat, processed meat, and heterocyclic amines and the risk of colorectal adenoma.
The team also investigated this relationship with the polycyclic aromatic hydrocarbons benzo(a)pyrene.
The researchers included 3696 left-sided descending and sigmoid colon and rectum adenoma cases and 34,817 endoscopy-negative controls.
| Adenoma of the descending and sigmoid colon were observed for the 2 heterocyclic amines|
The research team assessed dietary intake using a 137-item food frequency questionnaire, with additional questions on meats and meat cooking practices.
The questionnaire determined exposure to heterocyclic amines and polycyclic aromatic hydrocarbons.
The team found that intake of red meat, with known doneness, was associated with an increased risk of adenoma in the descending and sigmoid colon.
However, the researchers found that intake of red meat, with known doneness, was not associated with rectal adenoma.
The research team noted that well-done red meat was associated with increased risk of colorectal adenoma.
Increased risks for adenoma of the descending colon and sigmoid colon were observed by the team for the 2 heterocyclic amines.
The 2 heterocyclic amines included 2-amino-3,8-dimethylimidazo[4,5]quinoxaline and 2-amino-1-methyl-6-phenylimidazo[4,5]pyridine.
The team also noted an increased risk for adenoma with benzo(a)pyrene.
Greater intake of bacon and sausage was associated with increased colorectal adenoma risk, however, total intake of processed meat was not.
Dr Sinha's team concludes, “Our study of screening-detected colorectal adenomas shows that red meat, and meat cooked at high temperatures are associated with an increased risk of colorectal adenoma.”