Researchers at the University of California, San Diego School of Medicine, led by Dr. Ajit Varki, studied a non-human cellular molecule called N-glycolylneuraminic acid -- Neu5Gc. Neu5Gc is a type of glycan, or sugar molecule, that humans don't naturally produce, but that can be incorporated into human tissues as a result of eating red meat, Varki said.
The body then develops anti-Neu5Gc antibodies -- an immune response that could potentially lead to chronic inflammation.
"We've shown that tumor tissues contain much more Neu5Gc than is usually found in normal human tissues," Varki said in a statement. "We therefore surmised that Neu5Gc must somehow benefit tumors."
Using specially bred mouse models that lacked the Neu5Gc molecule -- mimicking humans before the molecule is absorbed into the body through ingesting red meat -- the researchers induced tumors containing Neu5Gc, and then administered anti-Neu5Gc antibodies to half of the mice.
In mice that were given antibodies, inflammation was induced and the tumors grew faster. In mice that were not treated with antibodies, the tumors were less aggressive, Varki said.
The study is published online in advance of print publication in the Proceedings of the National Academy of Sciences.