Well-done red meat may increase risk of bladder cancer
To investigate whether meat consumption increases the risk of bladder cancer, researchers from The University of Texas M.D. Anderson Cancer Center conducted a 12-year study involving 884 patients with bladder cancer and 878 cancer-free participants. Researchers used a questionnaire designed by the National Cancer Institute (NCI) to gather data about each participant's dietary habits. Participants were then categorized into four groups based on their intake of red meat, ranging from lowest to highest in intake.
Researchers found that the group who consumed the most red meat had almost 1.5 times the risk of developing bladder cancer compared to those with low levels of red meat intake. Consumption of beef steaks, pork chops, and bacon raised the risk significantly. Moreover, people whose diets included well-done meats were almost twice as likely to develop bladder cancer compared to those who preferred meats rare.
Further findings revealed that people with the highest estimated intake of three specific heterocyclic amines (HCAs) - by-products identified as possible carcinogens - were more than 2.5 times more likely to develop bladder cancer than those with low estimated HCA intake. “To quantify intakes of HCAs, we began three or four years ago to gather information on meat-cooking methods and doneness level, and then used a program developed by the NCI to estimate intakes of three major HCAs,” said the study's presenter Jie Lin, PhD, assistant professor in M.D. Anderson's Department of Epidemiology.
Additional research analyzed each participant's DNA and found that genetic variants in the HCA metabolism pathway may interact with red meat intake to increase the risk of cancer.
“This research reinforces the relationship between diet and cancer,” said Xifeng Wu, MD, PhD, professor in M.D. Anderson's Department of Epidemiology and lead author of the study. “These results strongly support what we suspected: people who eat a lot of red meat, particularly well-done red meat, such as fried or barbecued, seem to have a higher likelihood of bladder cancer. This effect is compounded if they carry high unfavorable genotypes in the HCA-metabolism pathway.”