Yet Another Reason Not To Eat Meat

Recently, I've been reading a lot about the "natural" human diet. Some people argue we've evolved to be meat eaters, others that we're naturally vegetarians. Obviously, we're pro-vegan here, but the question still rages. Are humans natural omnivores?

A few weeks ago, I bookmarked an article I saw referenced on It's taken me awhile to get around to reading it, but I'm glad I did. The article, entitled "Mystery of the meat-eaters' molecule" was published in The Telegraph, and postulates that human physiology may not be able to tolerate meat and dairy. The study is being conducted by Ajit Varki, co-director of the Glycobiology Research and Training Center at the University of California, San Diego.

Varki has built up a range of evidence that potentially links Neu5Gc, a so-called sialic acid, to chronic disease. This is because the animal version is absorbed by humans as a result of eating red meat and milk products, and there is evidence that the body views it as an invader.

Professor Varki has determined that we are the only primates who do not produce this molecule, Neu5Gc. Instead, we produce Neu5Ac, a precursor to Neu5Gc. So what does this mean?

This tiny change could potentially explain some of the more unusual differences between humans and apes. Chimpanzees do not seem to suffer from heart disease, cancers, rheumatoid arthritis or bronchial asthma - common conditions in humans.

Professor Varki believes that Neu5Gc elicits an immune reaction that might contribute to a whole spectrum of human-specific diseases.

After testing a range of foods, they found the highest levels of Neu5Gc in red meat: up to 11,600 micrograms could be absorbed from the recommended daily serving of beef, 5,100 from pork and 4,900 from lamb. The level in goat's cheese was 5,500, but fell to around 700 in milk and salmon. Cod, tuna, turkey and duck were in the twenties.

Not only did the foreign sugar show up in the body soon after eating, but tests also revealed that many people carry antibodies that react to Neu5Gc - a protective immune response, but one which could trigger damaging inflammation.

Interestingly, we've been reading more and more about how better health can be achieved by eating vegan, or at least cutting down on meat and dairy products. We've found information showing that rheumatoid arthritis can be improved with a vegan diet, and that non-fat and lo-fat milk can be linked to an increased risk of prostate cancer.

Of course, Varki's studies are still in their preliminary stages. As he stresses:

"we have not proven any link to disease, just suggested that it is something to explore."

I'm looking forward to reading more about his findings. On a lighter note, Kate posted this YouTube video and commented it's one of the funniest she's seen. I agree, so here it is, it may not be the definitive explanation, but hey, it supports my point of view ;).

For further reading:
Dept of Cellular and Molecular Medicine at UCSD
Varki Lab page


  1. I have also read, when I was researching MS after a friend of many years was diagnosed with it, that many resarchers believe that MS is caused by an immune-system reaction to dairy.

    Interestingly, I came to read this blog entry right after posting a response on the PCRM diabetes forum to someone asking whether people who are vegan are more likely to stay away from meat and dairy than people who are vegan for health reasons and can rationalize that “one turkey sandwich won’t hurt me.”

    My full response can be read here:

    But the short answer is – no, but only if the health vegan is really keeping up on the latest research. Dr. Caldwell Esselstyn has found that ***one meal*** with meat, dairy, or high fat foods like olive oil does a measurable amount of damage to the cardiovascular system.

    To me, something that visibly damages in one dose is not something I want to be putting into my body “in moderation” or, really, at all.

  2. There is one thing to keep in mind – and I say this as someone who is both a medical writer and a vegetarian who hopes to become a vegan – the risk of all of the illnesses mentioned in the article and the comments (with the possible exception of asthma) can be significantly (as much as 50% or more) lowered by vitamin D.

    However, not everyone produce vitamin D effectively from sunlight, and people living far from the equator (like me) can only get it from the sun less than half of the year. We need to take supplements. Not taking high-dose vitamin D supplements is a health risk similar to obesity or smoking!

    The problem is that vegan vitamin D, vitamin D2, is quite ineffective compared to vitamin D3, which is derived from animal sources. This is why I am taking vitamin D3. I have a serious immune system illness (most likely not autoimmune, but caused by a chronic viral infection) CFS/ME, which is also considered a pre-cancerous condition. I’m not going to take the risk of not taking vitamin D3.

    It could be that we would not need the protection from vitamin D if we ate a vegan diet. At the moment, no one knows. I don’t think there are any completely vegan human populations which could prove that being 100% vegan from birth [almost completely] prevents these illnesses. Thousands of people would be needed for a reliable study.

  3. The China Study makes a compelling case against the consumption of meat and dairy for similar reasons.

    Also, my mom has rheumatoid arthritis and she says it’s been improved since she switched to a vegan diet.

  4. Sparrow,

    With all due respect to Dr. Esselstyn, ingesting one turkey sandwich is unlikely to seriously hurt a healthy person (my 76-year old dad has eaten thousands of them and he wins 10K races in his age group). It will seriously hurt the turkey, however. That’s what prevents me from eating it.


    What do you think of the research (also discussed in The China Study) showing that both animal protein and high intake of calcium interfere with the body’s ability to produce the 1,25 vitamin D metabolite, which, according to China Study author T. Colin Campbell, PhD, “does most of the important work of vitamin D in our bodies?”

  5. Hi Sparrow,
    Yes, we saw a similar study and wrote about it here. But I’m not sure that simply being aware that something is bad for you is a deterrent. Look at all the smokers out there. We’ve already talked about the addictive nature of dairy…
    But as far as the damage is concerned, and I’m not a doctor nor am I a scientist, it would appear that most of the damage is minor as most of our population consumes these foods and lives in to their 70s-80s. Of course, our chronic diseases seem to be out of control…

    Hi Maija,
    First, sorry to hear about your illness. We wish you the best health possible.
    Thanks for sharing the info on vitamin D. We take a basic Calcium/D supplement. Looks like we’ll have to investigate further…

    Hi Elaine,
    It’s great that your mom is feeling better.

    Hi Gary,
    I agree that the level of damage isn’t likely to be that traumatic. I look at the elderly people I know, and all of them are meat eaters…

  6. Hi Sparrow,
    I’ve just been reading your comments on the PCRM board (didn’t know they had a board0. Very interesting thread. Thanks for sharing.

  7. Yeah, the PCRM board has saved my life. There’s so little support out there for low-fat veganism (most recipes have gobs of fat and, in my experience, most vegans just shrug if you ask for help and advice in lowering the fat content of recipes) that the fatfreevegan e-mail list and the PCRM message board became my lifelines as I learned to cook low-to-no fat.

    With my diabetes (gradually improving, thanks to Dr. Barnard’s program) I would be looking forward to a life of complications, eventually going on insulin, steady degradation of health, amputation and/or dialysis, and probably death before or by age sixty. I know this not just intellectually or philosophically but with concrete certainty because it’s what I watched so many of my close relatives go through.

    PCRM is, quite literally, saving my life. I owe them everything. And without that message board, I am not sure I would have had the support and strength to stay the course. Giving up meat, eggs, and dairy was easy. Keeping my fat intake around 10% has been a steep learning curve.

  8. “With all due respect to Dr. Esselstyn, ingesting one turkey sandwich is unlikely to seriously hurt a healthy person (my 76-year old dad has eaten thousands of them and he wins 10K races in his age group). ”

    “I agree that the level of damage isn’t likely to be that traumatic. I look at the elderly people I know, and all of them are meat eaters…”

    Y’all are forgetting that the “healthy as a horse right into old age, eating meat every day of my life” person is typically not the person who goes vegan for health. It is us poor suckers with a lousy genetic cocktail who hit forty and learn that we’ve got maybe another twenty years to live, tops, and those years are going to be full of pain, medications, surgerys, and feeling lousy. We are the ones who go vegan for health and living in Lousy Genetics Land keeps us vegan for health.

    And, yes, those of us who lost the genetics jackpot can subjectively *feel* the difference one crappy meal makes, once we’ve cleaned up our systems by eating good, low-fat vegan food for several months. I assure you that I can tell if a meal is 30% fat or higher even if I thought it was low-fat when I ordered it at a restaurant because I feel like utter hell about an hour after eating it.

    As much as I love animals, and as much as I cry when I see the slaughterhouse footage, the bottom line that keeps me vegan is that going vegan is seriously saving my life – you can see it in my blood test numbers every few months – and “stepping off the path” makes me feel wretched for at least the next 24 hours.

    When considering “vegan for health” and what it does to the body and mental attitude, you have to remember that the vast majority in that category (those who went vegan to be healthier) are like me, not like some 90-year-old trapeze artist who loves steak or some 76-year-old marathon runner who eats turkey sandwiches every day.

  9. Hi Sparrow,

    Fair point and I appreciate the perspective. There are those people, such as you and the patients in Dr. Esselstyn’s wonderful book, for whom veganism has literally saved their lives. That ‘s fantastic that PCRM’s dietary approach to diabetes has been a lifesaver for you. And probably at no rise in cost of living. Shame the medical profession as a whole hasn’t embraced this approach.

  10. Hi Sparrow,
    Wow, sorry to hear your health could potentially be that bad. Jane has a similar “bad gene” cocktail, but so far (knock on wood) nothing has manifested. But that was the impetus for us going vegan. She read Barnard’s book on diabetes and thought it made a lot of sense. While we’re not specifically lo-fat, Jane does take some of Barnard’s learnings to heart. He recommends “steam frying” things, and I have to say, Jane does that often, and I don’t really notice a difference (you just need a non-stick pan). We also love the “refried” black bean recipe from that book.

  11. You don’t even need a non-stick pan to do healthy saute. I do it in a good steel skillet all the time. I got out of the habit of non-stick when I was keeping pet birds and killed some of them accidentally by using non-stick cookware. I don’t have birds anymore, but I figure if the fumes released from using non-stick cookware killed my birds, they couldn’t be that good for me, either.

    As for my health, I think it’s getting better. I just realized I need to change my corrective eyewear prescription (though I have to wait a few months before the exam will be covered.) The diabetes was already making me go blind and the doctor stepped my presciption up two levels. After seven months low-fat vegan, he’s going to need to step it back down again! It’s way too strong for me now. That’s got to be a good sign.

  12. Hi Sparrow,
    Yikes! Is there anything out there that’s not dangerous to us in some way or another?

    Congratulations on getting your medications cut. That definitely sounds like a good sign to me. We hope it continues.

  13. No, my meds aren’t being cut . . . yet. I hope that does happen in the future. It’s my contact lens prescription that needs to be reduced. My low-fat vegan diet is reversing diabetes-caused progressive blindness.


  14. Gary: It is certainly possible and it would tip the scales more in favour of eating vegan, though I don’t think it would change the recommendation of taking vitamin D3.

    My personal opinion, based on loads of reading, is that most people should not be taking calcium supplements, unless there is a clear reason to (e.g. they have an illness that depletes calcium). I actually got side effects from taking a calcium supplement (back when I hadn’t researched this subject so thoroughly). My muscles were hurting all the time. It’s funny as I have tried loads of pills, both supplements and meds, and I hardly ever get side effects from anything – yet something which is generally used as a “placebo” made me feel worse.

    I also agree that the fact that most people live until fairly old age is no proof that the common Western diet doesn’t do much harm. Most people are taking loads of medications, and one in three people gets cancer in their lifetime. Many old people have a very low quality of life because of their health problems, despite their medications.

    And there are always people who smoke but still live to be 100… Which doesn’t mean that smoking doesn’t do much harm. It is interesting though that many countries (like Greece and Japan) have long life expectations despite huge smoking rates – because they eat more veggies and are less obese than e.g. the Americans.

    IMO there is no reason for most people to eat a very low-fat diet. If you are a vegan and aren’t eating loads of margarines with trans fats etc, you’re already getting mostly good fat. And the human body needs good fat, and to some extent the more the better. Of course if you’re obese, reducing the fat content of your diet may be a good way to lose weight, but you can lose weight by other ways as well. Fat does have satiating properties, and most vegan, non-refined fatty foods (like nuts and avocados) are extremely healthy.

  15. Maija:

    Fatty *foods* like avocados, olives, and nuts are very healthy for a person but a lot of problems can crop up with all the added *oils* that people eat, which are very bad for anybody (though people with higher health levels overall and better genetics are naturally going to see fewer problems with the added oils.)

    Here is a good article from Dr. McDougall about the potential pitfalls and dangers of added oils:

  16. Sadly, it quickly becomes clear that McDougall does not know what he’s talking about, regarding several things. For example, he claims that “However, people interested in losing weight should avoid nuts, nut butters, seeds, seed spreads, avocados, and olives, since they all serve as sources of concentrated, easy to consume, calories.” In fact in studies nuts have been shown to aid in weight loss, despite being fatty, because they are also very satiating. And unlike he claims, omega-3 oils do NOT suppress the immune system.

  17. Well, when a doctor promoting the “nut diet” gets as many spectacular success stories as McDougall now has, I’ll listen to him or her instead. For now, I’m bending my weight-loss ear in McDougall’s direction. He’s the one with all the photos of so many people who lost 70-100 pounds and kept it off by following his program.

    And I have to say that I didn’t need nuts or flax oil to lose the 112 pounds I’ve lost so far. And I’ve been quite satiated on a low-fat diet.

    So while what you say may be correct for every other human on the planet, this one individual human is going to stick with McDougalling.

    Proof is in the (low-fat, vegan) pudding.

  18. In 1998, I literally died in an ambulance from vomiting to death from Crohn’s Disease. Fortunately for me, the EMT’s jump-started my heart and brought me back, hence this comment.

    For me, another reason NOT to eat meat has actually several meanings. Staying alive, living healthy and keeping my body running in the cleanest possible way.

    The Vegan Diet, aka the Edenic Diet (see Genesis 1:29) is the ORIGINAL diet humans were supposed to eat from the beginning. It has healed my condition and restored my health and vitality completely.

    I ate a lot of animal foods growing up. However until I completely switched to the Vegan Diet and stopped eating ANY animal foods is where the transformation happened.

    This is my seventh year of eating Vegan with my family too, and we feel incredible.

    I still notice good changes going on inside my body and more and more healing is still taking place.

    I had to learn some hard lessons about obedience and I am still learning. I also learned how no human body is to eat ANY animal FAT or BLOOD, in any form.
    (See Leviticus 7:22-27).

    And what is in animal meats? Fat and blood, of course. Think about that for a moment.

    These two things cause so much illness in the human body and was never meant for us to eat in the first place. I am a living testimony to that fact.

    Now I never get sick or get a cold anymore like I did when I ate animal foods. It is such a relief to be whole and healthy again.

    Sure, eating a Vegan Diet takes practice, just like any other skill. You get better at it the more you do it. It is so worth the work. I feel it every day.

    It is my prayer that many more people will switch to this diet soon, so that their health can be the best for them as well.

    No one should suffer illness when they have the power of choice to change it.

  19. Some people say gluten and FODMAPS cause problems. I have some friends with MS and I have read about it because of them. Gluten and dairy can be both be problems for autoimmune. People also say what they call carbage is disease causing. I’m a believer, so I think white bread and other stuff that falls under carbage is dreadful. Ever since I read what biblelife has to say about food, I believe we could be vegan before the Fall, but in our fallen state, it’s a protein and B-12 deficient diet and “will blow your guts out.”(this is a quote from biblelife). The guy behind that sites says mentioned veggies(my nickname for vegetarians and vegans) are linked with animal worship. Some of my relatives are veggies, which is why I sometimes I read stuff about it. Even though I don’t believe in it personally, I don’t hate people whose view on being veggie differs from mine. I’m also an Aspie, so I maybe shouldn’t eat just anything. I had hair analysis as a kid and was found to be low in magnesium.

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