A new paper in the Proceedings of the National Academy of Sciences appears to offer a real explanation for the association between consumption of red meat and risk for cancer.
More than a decade ago, Tangvoranuntakul et al. initially postulated the idea that a product known as N-glycolylneuraminic acid (Neu5Gc) might be the defining culprit. They had discovered that Neu5Gc is commonly found in meat and dairy products from animals like cows, bison, sheep, goats, etc., but was not found naturally in humans, and was found at only very low levels in fish and in poultry. Eating products containing Neu5Gc seemed to have the potential to trigger abnormal responses in man.
In a new study published on line, and discussed in detail in an article on the U-T San Diego web site, Samraj et al. have now reported clear evidence that, when genetically human-like, Neu5Gc-deficient mice are fed a bioavailable form of Neu5Gc:
- They exhibit early evidence of systemic inflammation.
- They exhibit a a significantly higher (fivefold) incidence of carcinomas after long-term exposure to bioavailable Neu5Gc in their diet.
- There is a clear association between consumption of bioavailable Neu5Gc by the mice and accumulation of Neu5Gc in the tumors.
There may be a long way to go before we can establish with any degree of certainty that accumulation of unnaturally high levels of Neu5Gc in men as a consequence of eating red meat and dairy products is one of the key reasons for risk of prostate cancer in the “developed” world. However, one might very reasonably conclude, based on these data, that reducing one’s level of consumption of red meat and dairy products would lower one’s dietary consumption of bioavailable Neu5Gc and thus lower one’s risk for cancers of many types (prostate cancer included).
Indeed, Samraj et al. suggest that their research may also have implications for risk of other disorders exacerbated by inflammation, such as atherosclerosis and type 2 diabetes.
We would note that we have long argued that the development of prostate cancer, which may well take decades, may be stimulated by things we start to do in our childhood. This research would certainly seem to support that possibility, since high intake of red meat and dairy products is commonly initiated in childhood and continues over the next 40+ years until prostate cancer starts to become common among men in the 50s!
Filed under: Diagnosis, Prevention, Risk | Tagged: dairy, meat, N-glycolylneuraminic acid, Neu5Gc, red |
THE "NEW" PROSTATE CANCER INFOLINK 
Fascinating stuff! I wonder of organic dairy and meat have that substance in any lesser quantity. …
Thank you so much for posting this! While Neu5Gc clearly has a research history, I was not aware of it despite being reasonably current on prostate cancer nutritional developments. My diet has featured virtually no red meat (including pork) and very little dairy for the past decade and a half in order to combat prostate cancer. This research will strike many of us as highly relevant in elucidating the possible increased risk posed by red meat and dairy products and provide a lead to teasing out the extent of that risk.
There is a nominal cost for the full paper, but I hope to read it in the next few days.
Walt:
Mrs. Sitemaster had a similar reaction … thinking in terms of grass-fed as opposed to corn-fed animals. My personal suspicion is that it is likely to be more complex than that. If you read the article on the San Diego Union-Tribune web site, the research team actually suggests that the real opportunity here may be selective breeding for animals that express lower levels of Neu5Gc in their milk and their meat.
Hmm. perhaps what would have a benefit.
Sitemaster:
Selective breeding to eliminate Neu5Gc seems like a brilliant idea. Keep us posted on the progress of any efforts in that regard.
I totally believe this, in terms of dairy.
I have been a very heavy milk drinker since childhood, and began experiencing worrisome PSA levels between 4 and 7.25 ng/ml from age 40. I have long suspected milk, and wonder if the milk here in South Korea is somehow worse than back home in the USA?
After interviewing dozens of patients in my personal prostate cancer research, including post-treatment, I could find very few who did not eat red meat for decades. It seems all of us grew up with red meat and dairy. And even fewer wanted to change their diet to more vegetables, fruits, omega-3 fish, etc. Giving up red meat, dairy, and sugar seemed to be the most difficult thing to do, until they were diagnosed with cancer. They all talked a good game, but in reality, eating habits are hard to break. Please pass the brownies.
I would suggest anyone diagnosed with cancer or who knows others who are so diagnosed read Radical Remission by Dr. Kelly Turner. She discusses not only dietary changes, but also taking control of one’s health through nutrition, releasing suppressed emotions, and focusing on positive emotions, too. Diet alone is just one part of the movie.
Hi elucidated1,
Thanks for your observations on eating habits among prostate cancer patients. Your thoughts tally with my own experience. On the positive side, there is a sizable population that does follow these wise guidelines, even as young adults: marathon runners. I’m basing that on hundreds of conversations over the years with attendees and competitors at the Health and Fitness Expos that precede the Marine Corps Marathon each October in Washington, DC, and the Historic Half Marathons in late spring in Fredericksburg, VA, near the Marine base at Quantico. Our Virginia Prostate Cancer Coalition usually has an information booth at these events, and we find we typically are “speaking to the choir” about diet and nutrition.
I made all those changes 15 years ago after diagnosis … except for sugar. I haven’t added any sugar to cereal for decades and drink no sodas, but I get sugar through daily wine, fruit, daily dark chocolate, and a few other sweets. Fortunately, sugar seems not to be a significant energy source for prostate cancer, except for a small proportion of cases, such as some cases with very aggressive prostate cancer. And don’t hog all the brownies!
CORN- VS. GRASS-FED ISSUE
Hi Sitemaster and Walt.
Dr. Charles Myers, known to many of us as Snuffy, is convinced that the feed does make a significant difference, and he cites a respectable body of supportive research. He’s keenly concerned about the omega-6/omega-3 ratio, with corn as a prominent source of omega-6 in the American diet.
I have never heard him (or anyone else) discuss Neu5Gc, but he has repeatedly cautioned about foods such as red meat that are major sources of arachidonic acid.
It would be great if Snuffy would notice this discussion and chime in.
I don’t think Dr. Myers will enter this discussion here. I posted comments on his website and they were deleted. It seems his posts are proprietary and he’s looking for revenue.