A new study suggests that Neu5Gc, a non-human sugar found in red meat, promotes inflammation and causes cancer. The study was published in the online edition of the Proceedings of the National Academy of Sciences.

The study was conducted to understand why people who consume a lot of red meat are at higher risk for some cancers than those people who eat other types of meat.

The study was conducted at the University of California, at the San Diego School of Medicine. The researchers initially carried out a methodical survey of common foods and found that red meats such as beef, pork and lamb have high amounts of a sugar called Neu5Gc. These meats are major sources of Neu5Gc in the human diet.

The researchers found that giving Neu5Gc to mice that are lacking in the sugar (similar to humans) considerably promoted spontaneous cancers. The researchers did not expose the mice to other carcinogens, further associating Neu5Gc with cancer.

Principal investigator Dr. Ajit Varki, professor of cellular and molecular medicine at University of California, San Diego, said: “Until now, all of our evidence linking Neu5Gc to cancer was circumstantial or indirectly predicted from somewhat artificial experimental setups.

This is the first time we have directly shown that mimicking the exact situation in humans – feeding non-human Neu5Gc and inducing anti-Neu5Gc antibodies – increases spontaneous cancers in mice.”

Previously, researchers had found that animal Neu5Gc may be absorbed into human tissues. This particular study suggests that eating red meat could result in inflammation if the immune system is continuously creating antibodies against the ingested animal Neu5Gc. Chronic inflammation causes tumour formation.

“This work may also help explain potential connections of red meat consumption to other diseases exacerbated by chronic inflammation, such as atherosclerosis and type 2 diabetes,” Varki noted.

“Of course, moderate amounts of red meat can be a source of good nutrition for young people. We hope that our work will eventually lead the way to practical solutions for this catch-22 situation,” the authors concluded.