Neu5Gc: A Sugar Molecule That May Not Be So Sweet

Neu5Gc: a sugar molecule that many not be so sweet

By Benjamin V. Treadwell, Ph.D.

Parents often complain that the food their children eat does not “stick with them.” That might seem like an advantage if they were aware of what you’re about to read. Recent research shows specific constituents of certain foods go beyond sticking to us. These substances are more like intruders, uninvited guests that can wreak havoc on our bodies instead of nourishing them.

What’s at Steak
This new experimental evidence demonstrates, perhaps for the first time, how and why certain foods can promote cancer growth. Red meat was identified as one of those foods.

Numerous epidemiological studies support the findings. Populations who commonly consume significant amounts of meat, especially red, have reported a higher incidence of certain cancers, compared to populations whose diet is predominantly fish, vegetables, fruit, and legumes. But what, exactly, is the connection between red meat and cancer?

Not-so-sweet Molecules
For some time, scientists studying cancerous tissues have observed that cells of malignant growths contain abnormal sugar and sugar-like molecules, which extrude on the cell’s surface. One of these, a sialic acid sugar called Neu5Gc, is normally present in most mammals but lacking in humans, due to the absence of a gene necessary for its synthesis.

In spite of the human inability to make the sialic acid sugar, Neu5Gc, its presence has been reported in human tumors, including colon carcinomas, retinoblastomas, breast cancers, and melanomas. So the team of investigators, who undertook the recent research, asked: where does the Neu5Gc originate?

Their study suggests the probable source of the Neu5Gc is diet, more specifically foods containing high levels of this sialic acid sugar, among them red meat and milk products. Both of these foods also have a significant association with cancer risk.

Exception and Explanation
If diet is the key, why do some red-meat/milk-product consumers seem to be disease-free? Blood analyses detected antibodies to the sialic acid sugar, indicating its presence. The key determinant seemed to be the absence of precancerous cells.

This observation led to further in vitro cancer cell study. Although the researchers didn’t conclusively demonstrate that Neu5Gc causes cancer, they do present strong evidence that Neu5Gc stimulates pre-existing cancerous growth through the following processes:

The Neu5Gc on the cell’s surface is recognized as a foreign substance. (Remember, humans don’t produce it.) In response, the immune system is mildly activated in an attempt to destroy it. As with many immune reactions, there is associated inflammation. Certain growth factors are secreted by the invading inflammatory cells.

One of these, VEGF, initiates the growth of new blood vessels, which function as conduits, bringing more nutrition to the cells in the area, both malignant and normal. In other words, the foreign Neu5Gc sugar, adhering to the exterior of the tumor cell, indirectly feeds the cancer.

Immune System Malfunction?
Our immune system is supposed to protect us from disease, including cancer. However, it seems to be most effective when it defends with rapid and overwhelming force. On the other hand, an immune response resulting in chronic, low-grade inflammation has long been associated with many diseases (diabetes, heart disease, Alzheimer’s disease, etc.), most prominently cancer. 

It appears, from the study summarized here and others, that a mild or chronic inflammation is just what the malignant cell requires to grow. This hypothesis is also upheld by studies showing decreased cancer risk in people who take non-steroidal, anti-inflammatory drugs such as aspirin and the COX-2 inhibitors.

Experiments with mice, exhibiting tumors bearing the Neu5Gc sugar, corroborated the effectiveness of anti-inflammatory drugs. Tumor growth increased after the mice were injected with the antibody to Neu5Gc. However, if the animals were treated with an anti-inflammatory agent then injected with the antibody, the stimulatory effect was largely eliminated.

Which brings us to the question of the relationship between Neu5Gc, its antibody and cancer. Our cousins, the chimpanzees, may actually hold another clue. Unlike humans, chimps can synthesize this sialic acid sugar. Since it is not foreign to their immune systems, antibodies aren’t produced. Interestingly, chimpanzees rarely develop the types of cancers associated with Neu5Gc-bearing tumors.

Eat No Evil
Although the research results described here are impressive, they are not conclusive. Still, humans may benefit from mimicking the chimps’ condition. The less Neu5Gc we ingest, the fewer antibodies and related chronic low-grade inflammation will be produced.

In other words, it may be prudent to consume modest amounts of red meat and milk, favoring other protein sources (fish, poultry, legumes) instead. By simply changing our food choices, we could reduce the incidence of certain cancers as well as other diseases associated with inflammation.


Research Update

In a recent issue of Proceedings of the National Academy of Sciences (PNAS), four researchers from the University of California, San Diego, publish new “Evidence for a human-specific mechanism for diet and antibody-mediated inflammation in carcinoma progression.” The team discusses the groundbreaking results of their study on the potential role specific molecules may play in human cancer cell growth.

For the first time, these scientists show that a non-human molecule, contained in specific foods we eat, becomes attached to the surface of human cells. They also show that certain food types, already associated with increased cancer risk, contain the molecule in question, a sugar-containing sialic acid, Neu5Gc. In their research, this molecule is recognized by the human host’s immune system as a foreign substance, with subsequent antibody production to the molecule.

The investigators demonstrate that it is this immune reaction to the Neu5Gc that activates the growth of pre-existing cancer cells. Consistent with previous research, they note that mild inflammation associated with an immune reaction attracts specific inflammatory cells to the source of the immune response. The newly recruited cells, which are part of our immune defense, synthesize specific substances that stimulate the growth of blood vessels as well as other cell-growth promoting factors. The presence of new blood vessels supports not only normal cell, but also cancer cell growth, with more nutrients now being delivered to them.

The investigators cite additional work, including epidemiological studies, to support their hypothesis that certain foods – red meat and milk – that contain significant amounts of Neu5Gc are associated with a higher incidence of certain cancers. They also cite work demonstrating that cancer cells contain large amounts of sialic acid sugar residues on their membrane surface.

The group further speculates that some cancers may require a mild immune response, like the one associated with Neu5Gc on the cell surface, to convert a relatively latent cancer to an active, fast-growing pathology.

Read article abstract here.

This Research Update column highlights articles related to recent scientific inquiry into the process of human aging. It is not intended to promote any specific ingredient, regimen, or use and should not be construed as evidence of the safety, effectiveness, or intended uses of the Juvenon product. The Juvenon label should be consulted for intended uses and appropriate directions for use of the product.

Ask Ben

Dr. Treadwell answers your questions about Juvenon™ Cellular Health Supplement

question: As a 73-year-old, steady taker of two Juvenons daily for three years or so, I can generally only report positive results. So, is there any basis for the growing concern that my (of late) increasingly vivid, unpleasantly insistent and circular, often sleep-interrupting dreaming might originate from those same – perhaps by now jubilant – Juvenon-improved mitochondria? Can you shed any light on this dilemma, on the horns of which I sit pondering if reducing or eliminating Juvenon might help? – P 

answer: Many people have commented that Juvenon seems to affect the content of their dreams. In fact, there is some evidence that one of the components in Juvenon may increase the synthesis of a neurotransmitter, acetylcholine. High levels of this transmitter may improve memory retention during the day. Recent evidence, however, indicates elevated acetylcholine levels may also interfere with memory processing during sleep. As this neurotransmitter is short-lived, try taking your second Juvenon tablet at noon, or at least eight hours before bedtime. Please let me know if that helps resolve your dreaming “nightmare.”

Benjamin V. Treadwell, Ph.D., is a former Harvard Medical School associate professor and member of Juvenon’s Scientific Advisory Board.