Processed meats can include ham, sausage, bacon, deli meats (such as bologna, smoked turkey and salami), hot dogs, jerky, pepperoni and even sauces made with those products. When meat is processed, it is transformed through curing, fermenting, smoking or salting in order to boost flavor and shelf life.
In 2015, the World Health Organization announced that processed meat was “carcinogenic to humans,” citing “sufficient evidence” that it caused colorectal cancer. The World Cancer Research Fund International recommends eating little, if any, processed meat, and limiting red meat to about three portions (or about 12 to 18 ounces) per week. It’s important to limit intake of red meat — most commonly beef and pork in the United States — even when it’s not processed, because it’s tied to not only cancer, but also heart disease, stroke and an overall risk of death. (In its 2015 announcement about processed meats, the W.H.O. classified red meat as “probably carcinogenic.”)
Experts can’t definitively recommend one type of processed meat over another because of the way research is currently conducted. “Most studies focus on highly consumed processed meats — hot dogs, bacon, sausages,” Dr. Hu said. So, because all types of processed meats get lumped together in most studies, he added, “it’s difficult to make a conclusive statement regarding which processed meats are better or worse than others.” And, he noted, people who tend to eat one type of processed meat tend to eat others, so it’s challenging to tease out the effect of one over another.
“Theoretically, you can argue that processed poultry and fish are not as bad as processed red meat,” Dr. Hu said, citing the lower saturated fat content of poultry and fish and the abundance of omega-3 fatty acids in certain types of fish. “But we don’t have evidence to support this,” he said, so until more research is done, treat processed poultry and fish products with similar caution.