The study conducted at the University of California, San Diego School
of Medicine found that feeding Neu5Gc to mice engineered to be
deficient in the sugar (like humans) significantly promoted
spontaneous cancers. The study did not involve exposure to carcinogens
or artificially inducing cancers, further implicating Neu5Gc as a key
link between red meat consumption and cancer.
Principal investigator Ajit Varki, MD, Distinguished Professor of
Medicine and Cellular and Molecular Medicine, said that until now, all
of their evidence linking Neu5Gc to cancer was circumstantial or
indirectly predicted from somewhat artificial experimental setups and
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.
The researchers had previously discovered that animal Neu5Gc can be
absorbed into human tissues. In this study, they hypothesized that
eating red meat could lead to inflammation if the body's immune system
is constantly generating antibodies against consumed animal Neu5Gc, a
foreign molecule. Chronic inflammation is known to promote tumor
Varki added that the final proof in humans will be much harder to come
by but on a more general note, this work may also help explain
potential connections of red meat consumption to other diseases
exacerbated by chronic inflammation, such as atherosclerosis and type
The study is published in the online early edition of the Proceedings
of the National Academy of Sciences.