Red Meat’s Smoking Gun
For years, I and other nutrition experts have warned that red meat consumption is linked to a greater risk of certain cancers. This association between higher red meat consumption and the risk of serious disease is apparent from numerous studies. They’ve noted a significantly higher risk of colon cancer, for instance, among meat eaters. These studies have also implicated processed meats; sausages, salami, bacon, lunch meats, etc. Pork—which has been marketed as “the other white meat”—is, unfortunately, also implicated.
Poultry and fish are NOT associated with any increased cancer risk.
For years, scientists speculated that a class of chemicals formed when red meat is exposed to high heat—heterocyclic amines (HCAs)—was responsible for this risk. HCAs are known carcinogens. But even when red meat is not cooked at high temperatures, the risk remains. Other suspects include the nitrates and nitrites, which are used as preservatives in processed meats (hot dogs are a notable source of these troubling chemicals). Nitrites are converted in the body to nitrosamines, which are also carcinogenic.
Not all red meat contains added nitrites, however. Yet the increased risk of cancer remains. This suggests there’s something else about red meat that causes problems. Now investigators say they’ve finally discovered what it is. Turns out it’s a form of sugar; a molecule found only in the meat of mammals. It’s called NEU5Gc.
The human body treats this compound as an invasive foreign substance. In fact, NEU5Gc triggers an immune response, prompting inflammation and provoking the production of antibodies. Scientists now think these anti-NEU5Gc antibodies, and the chronic inflammation they signal, are responsible for the promotion of tumors. Researchers at the University of California, San Diego, have demonstrated this process in mice bred to mimic the process that occurs in humans.
As it turns out, the term “red meat” may be misleading. As I mentioned, pork may be the “other white meat,” but it’s also problematic. That’s because a more accurate term would be “mammalian meat”. NEU5Gc is a mammalian compound, so it’s only the meat of other mammals that is of concern to us. Virtually all mammals eaten for meat possess this compound, but humans do not. As such, our bodies treat it as a foreign substance. And foreign substances are invariably identified by the immune system as a threat, to be neutralized.
It’s interesting to note than the extremely healthful Mediterranean diet has never included much red meat. In traditional Mediterranean cultures, red meat was seldom available. When consumed at all, it’s more likely to be used as an incidental flavoring ingredient, and far less often as a main course item.
And now you know. For optimal, vibrant health, just say “no” to mammalian meat. Choose fish, chicken, turkey, or duck, instead, when you’re feeling carnivorous. In theory, you could experience relief from any number of inflammation-related conditions.
Annie N. Samraj, Oliver M. T. Pearce, Heinz Läubli, Alyssa N. Crittenden, Anne K. Bergfeld, Kalyan Banda, Christopher J. Gregg, Andrea E. Bingman, Patrick Secrest, Sandra L. Diaz, Nissi M. Varki, and Ajit Varki. A red meat-derived glycan promotes inflammation and cancer progression. PNAS, December 2014 DOI: 10.1073/pnas.1417508112