While the effect of eating meat on the risk of developing cancer is a contentious topic, the evidence that long-term consumption of red meat is strongly linked with a modest, but significant, increase in the risk of developing bowel cancer is convincing.
However, scientists found that a particular sugar, which is present in high quantities in red meat, could be triggering an inflammatory immune response, which is known to encourage the development of cancers.
One factor that scientists identified as a potential culprit for red meat’s apparent carcinogenic effects is a sugar called Neu5Gc, which is found in most carnivores but not humans. Even though humans can’t synthesize this molecule, it has been found in high levels in some cancerous tissue.
To find out more about whether this sugar could be contributing to the increased cancer risk, scientists from the University of California, San Diego, surveyed common foods to find out which contained the most Neu5Gc. They found that it is highly and selectively enriched in red meat, such as pork, beef and lamb.
The researchers found that the presence of this sugar in our bodies could be triggering an immune response, which in turn leads to inflammation and subsequently the promotion of tumor formation.
They fed mice a diet enriched with Neu5Gc for 12 weeks and gave them regular injections with Neu5Gc antibodies to replicate what happens in our bodies. Sure enough, the mice developed systemic inflammation and experienced a five-fold increase in the incidence of cancers.
The results could provide a possible explanation for the links between red meat consumption and other diseases worsened by chronic inflammation, such as type 2 diabetes.