2.1: 3.1: web.health/cancer/immune response to mammalian meat and milk:
. eaters of mammalian meat seem more prone to cancer [pnas 2014]
than eaters of other types of animal protein;
a sugar called Neu5Gc, is found in most mammals
but not in humans; and,
humans often have high levels of Neu5Gc-specific antibodies
(perhaps developing inflammation when they eat it)
[Nat Biotechnol. 2010];
scientists wondered if humans are troubled by
eating a foreign sugar such as Neu5Gc
so they engineered mice to not make that sugar
in order to have them better model human reactions;
and, when the new mice were then fed the Neu5Gc,
they were more prone to spontaneous cancers. [ucsd.edu]
"The bound form of Neu5Gc is bioavailable,
undergoing metabolic incorporation into human tissues,
despite being a foreign antigen.
Interactions of this antigen with circulating anti-Neu5Gc antibodies
could potentially incite inflammation.
Indeed, when human-like Neu5Gc-deficient mice
were fed bioavailable Neu5Gc
and challenged with anti-Neu5Gc antibodies,
they developed evidence of systemic inflammation.
Such mice are already prone to develop
occasional tumors of the liver,
an organ that can incorporate dietary Neu5Gc.
Neu5Gc-deficient mice immunized against Neu5Gc
and fed bioavailable Neu5Gc
developed a much higher incidence of hepatocellular carcinomas,
with evidence of Neu5Gc accumulation" [pnas 2014].
. Neu5Gc is found in most mammalian meat and milk protein;
and also in fish eggs but not fish meat
and not in chicken or chicken eggs [pnas 2014].
the article documenting the engineered mice study:
"A red meat-derived glycan promotes
inflammation and cancer progression" [pnas 2014].
conflict of interest:
. the principal investigator is Ajit Varki, MD;
he and Nissi Varki are co-founders and
have equity interest in SiaMab Therapeutics, Inc.,
a biotech company with an interest in Neu5Gc
and anti-Neu5Gc antibodies. In addition,
Ajit Varki is a member of SiaMab Therapeutics,
Inc.’s Board of Directors and is a Scientific Advisor to the company