Neu5Gc: A Sugar Molecule That May Not Be So Sweet

Parents often complain that the food their childrenactivated in an attempt to destroy it. As with many
eat does not "stick with them." That might seem likeimmune reactions, there is associated inflammation.
an advantage if they were aware of what you'reCertain growth factors are secreted by the invading
about to read. Recent research shows specificinflammatory cells.
constituents of certain foods go beyond sticking toOne of these, VEGF, initiates the growth of new
us. These substances are more like intruders,blood vessels, which function as conduits, bringing
uninvited guests that can wreak havoc on our bodiesmore nutrition to the cells in the area, both malignant
instead of nourishing them.and normal. In other words, the foreign Neu5Gc
What's at Steaksugar, adhering to the exterior of the tumor cell,
This new experimental evidence demonstrates,indirectly feeds the cancer.
perhaps for the first time, how and why certainImmune System Malfunction?
foods can promote cancer growth. Red meat wasOur immune system is supposed to protect us from
identified as one of those foods.disease, including cancer. However, it seems to be
Numerous epidemiological studies support the findings.most effective when it defends with rapid and
Populations who commonly consume significantoverwhelming force. On the other hand, an immune
amounts of meat, especially red, have reported aresponse resulting in chronic, low-grade inflammation
higher incidence of certain cancers, compared tohas long been associated with many diseases
populations whose diet is predominantly fish,(diabetes, heart disease, Alzheimer's disease, etc.),
vegetables, fruit and legumes. But what, exactly, ismost prominently cancer.
the connection between red meat and cancer?It appears, from the study summarized here and
Not-so-sweet Moleculesothers, that a mild or chronic inflammation is just
For some time, scientists studying cancerous tissueswhat the malignant cell requires to grow. This
have observed that cells of malignant growthshypothesis is also upheld by studies showing
contain abnormal sugar and sugar-like molecules,decreased cancer risk in people who take
which extrude on the cell's surface. One of these, anon-steroidal, anti-inflammatory drugs such as aspirin
sialic acid sugar called Neu5Gc, is normally present inand the COX-2 inhibitors.
most mammals but lacking in humans, due to theExperiments with mice, exhibiting tumors bearing the
absence of a gene necessary for its synthesis.Neu5Gc sugar, corroborated the effectiveness of
In spite of the human inability to make the sialic acidanti-inflammatory drugs. Tumor growth increased
sugar, Neu5Gc, its presence has been reported inafter the mice were injected with the antibody to
human tumors, including colon carcinomas,Neu5Gc. However, if the animals were treated with
retinoblastomas, breast cancers, and melanomas. Soan anti-inflammatory agent then injected with the
the team of investigators, who undertook the recentantibody, the stimulatory effect was largely
research, asked: where does the Neu5Gc originate?eliminated.
Their study suggests the probable source of theWhich brings us to the question of the relationship
Neu5Gc is diet, more specifically foods containing highbetween Neu5Gc, its antibody and cancer. Our
levels of this sialic acid sugar, among them red meatcousins, the chimpanzees, may actually hold another
and milk products. Both of these foods also have aclue. Unlike humans, chimps can synthesize this sialic
significant association with cancer risk.acid sugar. Since it is not foreign to their immune
Exception and Explanationsystems, antibodies aren't produced. Interestingly,
If diet is the key, why do some red-meatchimpanzees rarely develop the types of cancers
milk-product consumers seem to be disease-free?associated with Neu5Gc-bearing tumors.
Blood analyses detected antibodies to the sialic acidEat No Evil
sugar, indicating its presence. The key determinantAlthough the research results described here are
seemed to be the absence of precancerous cells.impressive, they are not conclusive. Still, humans may
This observation led to further in vitro cancer cellbenefit from mimicking the chimps' condition. The less
study. Although the researchers didn't conclusivelyNeu5Gc we ingest, the fewer antibodies and related
demonstrate that Neu5Gc causes cancer, they dochronic low-grade inflammation will be produced.
present strong evidence that Neu5Gc stimulatesIn other words, it may be prudent to consume
pre-existing cancerous growth through the followingmodest amounts of red meat and milk, favoring
processes:other protein sources (fish, poultry, legumes) instead.
The Neu5Gc on the cell's surface is recognized as aBy simply changing our food choices, we could
foreign substance. (Remember, humans don't producereduce the incidence of certain cancers as well as
it.) In response, the immune system is mildlyother diseases associated with inflammation.