It’s not about the quality of the meat, or whether it’s from the local butcher or supermarket, that’s the issue. The evidence so far suggests that it’s probably the processing of the meat, or chemicals naturally present within it, that increases cancer risk. Researchers are still trying to pin down exactly how red and processed meat cause cancer, but the main culprits seem to be certain chemicals found in the meat itself. Processed red meats contain chemicals, such as nitrite preservatives, that generate certain compounds in the gut that can cause cancer.
Cooking meat at high temperatures, such as grilling or barbecuing, can also create chemicals in the meat that may increase the risk of cancer. These chemicals are generally produced in higher levels in red and processed meat compared to other meats. There are also other theories, says Cancer Research UK – some research suggests iron in red meat could play a part, and the bacteria in the gut might play a supporting role, too.