Researchers from Queen's University Belfast are calling for the ban of nitrite-cured meat after a new study found a substantial link with colorectal cancer. The study saw mice fed nitrite-cured meat develop significantly more tumors than animals fed either nitrate-free meat or no meat at all.
Nitrites and nitrates are key preservatives used in the manufacturing of many cured meat products. The vast majority of bacon on supermarket shelves, for example, contains nitrites but a growing body of research has emerged to suggest these chemicals may be linked to cancer.
In 2015 the International Agency for Research on Cancer (IARC), a World Health Organization research organization, classified processed meat as a Group 1 carcinogen. The agency linked diets high in processed meats with a significantly increased risk of several cancers.
Since then, further research has homed in specifically on the relationship between nitrites, a food-preserving chemical, and cancer. A new study, published in the Nature journal NPJ Science of Food, set out to explore the effect of nitrites on mice engineered to be susceptible to colorectal cancer.
Unlike some prior studies which fed animals unusually high volumes of nitrites, this new research attempted a more moderate chemically infused diet. For eight weeks a cohort of mice was fed either nitrite-containing frankfurter sausage, nitrite-free sausage or nitrite-free pork.
Only 15% of the animals' total diet consisted of either nitrite-containing or nitrite-free pork. The researchers note this is still a high dietary intake of processed meat, relative to what a human would consume. However, prior studies have utilized feeding models of over 50% processed meat, so this is a much more moderate amount than previous investigations linking nitrites and cancer.
"In terms of the overall number of GI tumors, the frankfurter group had the highest with a mean of 11.2 and this was significantly more (p = 0.002) than the control which had a mean of 7.3 tumors, it was also significantly higher (p = 0.029) than the sausage group which had a mean of 8.6 tumors, and significantly higher (p = 0.019) than the pork group which had a mean of 8.3 tumors," the researchers write in the study.
Chris Elliot, director of the Institute for Global Food Safety at Queen’s University, said the study findings affirm the relationship between nitrites and cancer. He argues nitrites should be banned from food products as they are easily replaced with natural, safer alternatives.
“The results of this new study make the cancer risk associated with nitrite-cured meat even clearer," Elliot said. "The everyday consumption of nitrite-containing bacon and ham poses a very real risk to public health.”
In mid-2022 France became one of the first countries in the world to formally begin limiting the use of nitrites in food products. Following a report from its food safety agency confirming the association between nitrite-containing processed meat and cancer, the government began to move to reduce nitrite use in food.
The new study was published in the journal spj Science of Food.