Scientists from UC San Diego recently discovered that red meat elevates the risk of cancer because it contains a chemical that is unnatural to human biology.
The report, published on Monday in the Proceedings of the National Academy of Sciences, diverges from a popular hypothesis that the higher risk comes from carcinogenic chemicals produces by grilling.
Instead the research concluded that when people consume beef, pork, lamb and bison, a sugar molecule called Neu5Gc from those meats gets fully incorporated into human tissue. Unfortunately, the human immune system attacks that substance, which leads to tissue inflammation and a higher lifetime risk of cancer.
This same process could also occur when people consume whole milk, certain cheeses and caviar. Fish can also produce Neu5Gc, but they store it in their eggs and not their fleshy muscles.
The research was conducted on two groups of mice, one that naturally had Neu5Gc and another that was genetically engineered to no longer have the molecule, thus mimicking human biology. The specially engineered mice showed a cancer rate that was more than five times that of the other group.
The Neu5Gc phenomenon is unprecedented.
This foreign sugar is like a Trojan Horse, it becomes a part of a person’s own cells. This is the first substance that scientists have discovered that is foreign that gets totally incorporated into the body despite the fact that the immune system recognizes it.
Earlier studies have linked red-meat consumption to a number of cancers, especially colorectal, breast, prostate, ovarian and lung cancer.
The scientists participating in the research despite the data do not recommend people cutting red meat from their diets. Lean red meat’s nutritional benefits may outweigh the cancer risks for people younger than 30 or 40. However, after that age threshold, the harmful effects tend to dominate.
Selective breeding may allow ranchers to reduce the amount of Neu5Gc. In addition, it may be possible to develop an antidote to counteract the cancer risk.