Red meat and heterocyclic amine intake, metabolic pathway genes and bladder cancer risk

Newswise, April 2010-- High consumption of red meat or fried meat and a person’s genetic makeup are all associated with an increased risk of developing bladder cancer.

“The most interesting finding was that the magnitude of the meat-cancer association depends on a person’s genetic background,” said first author of the study Jie Lin, Ph.D., assistant professor in the department of epidemiology at the University of Texas M. D. Anderson Cancer Center, Houston.

Using data collected in a large Texas bladder cancer case-control study, Lin and colleagues analyzed the association between meat consumption, cooking methods, genetic predisposition and bladder cancer risk.

The study included 884 patients with confirmed bladder cancer and 878 controls. Epidemiologic and dietary data, including meat intake and meat cooking methods, were collected using standard food frequency questionnaires.

Higher consumption of beef steaks, pork chops and bacon were each associated with increased bladder cancer risk, according to Lin. But these results were not limited to just red meat; fried chicken and fried fish conferred an increased bladder cancer risk when consumed in high amounts.

When evaluating the effect of cooking method, Lin and colleagues found meats cooked at the medium-done and well-done level were associated with a 1.46-fold and 1.94-fold increased risk, respectively, when compared to the rare-done level. Lin explained that high temperature-cooking methods generate heterocyclic amines, which are carcinogenic compounds that increase cancer risk.

“Reducing red meat consumption and/or avoiding eating meats cooked at very high temperature, like those pan-fried, grilled or barbecued, may reduce one’s risk for developing bladder cancer,” said Lin.

Results also indicated that some participants were genetically predisposed to cancer risk; those who carried a high number of unfavorable genotypes in the pathway had a more significant risk of developing bladder cancer. This suggests that red meat intake and genetic variants in the metabolic pathways influence bladder cancer susceptibility.

“Cancer is caused by multiple risk factors — such as environmental exposure, diet and genetic background — and their interactions,” Lin said. “The current results highlight the importance of studying gene-diet interactions in cancer risk assessment and have valuable implications in bladder cancer prevention.”