Dr. Seale: “any B12 present in animal foods is only because of bacterial contamination”
I was astounded to receive a link to a recent blog post by Stuart A. Seale, MD, this morning. Dr. Seale believes there’s a lot of misinformation about the necessity of eating animal foods to obtain Vitamin B12.
What You Need to Know About Vitamin B12
It is true that vitamin B12 is found in animal foods, and plant foods contain very little. However, animals do not have the ability to manufacture vitamin B12, so the presence of B12 in animal foods is not because of some superior characteristic of the food source. In fact, it is bacteria found in the intestinal tracts of animals that produce vitamin B12. Therefore, any B12 present in animal foods is only because of bacterial contamination. This doesn’t sound much like the makings of a superior dietary component, does it? Because of the simple fact that they don’t have intestinal tracts, and therefore intestinal bacterial contamination, plant foods contain little or no vitamin B12. Bacteria in soil also can produce B12. In earlier days people actually got their hands dirty while trying to subsist, and this was probably a source of this nutrient for them.
At first I mistakenly took the Dr. to mean that intestinal flora itself constituted “bacterial contamination,” so I’m damn glad I took a closer look because this post would have read far differently, otherwise. Thankfully, both reading it over more carefully — as well as supplemental information provided in a comment by Dr. Seale — informed me that he was not, indeed, bacteriophobic.
Regarding B12 in plant foods -there aren’t any plant sources of B12 that are reliable, only because B12 is manufactured by bacteria. These bacteria reside in the colon of animals, including people, but the B12 made isn’t absorbed into the bloodstream because the colon is too far down the intestinal pathway. B12 is absorbed in the small intestine. The presence of B12 in animal foods is only because of contamination with intestinal bacteria. As my blog attempted to point out, B12 in animal foods doesn’t make them superior to plant foods – it only means they are more bacterially contaminated. It also doesn’t mean that man has evolved in some way to be a meat-eater because meat has been the only place to obtain B12. It is the relatively modern industrialized slaughterhouse process that has led to the bacterial contamination problem with animal foods. Likewise, modern industrialized agriculture has also sterilized our soils. We also now live in a bacteriophobic culture. Undoubtedly in times past when society was agrarian, soil bacteria were an important source of B12. Dirt on the hands, under the nails, and on the food that was eaten would be enough to supply adequate B12.
OK, so now I have two distinct approaches by which to challenge the doctor’s claims. The first is simply the apparent bias since, what’s the big different between eating dirty vegetables and putting your dirty fingers in your mouth, and having a little trace fecal contamination on your meat — or, I suppose, eating the entire digestive tracts of clams and oysters, both high sources of B12?
Where does he think at least a good portion of the B12 in dirt comes from, if not the droppings of various animals and birds on and around crops? “Dirt” is composed of a lot of things including waste from dead and rotted animals & bugs, as well as their waste products.
OK, fine, go right ahead and get your B12 from dirty veggies, and feel free to clean under your fingernails with your teeth. Or, go barefoot and lick your feet. My dogs do and it seems to work for them.
The second dispute I have is his apparent conflation of the digestive systems of humans and ruminants.
Bovine Digestive Tract
While my knowledge of human and bovine physiology is deficient at best, I did seem to have picked up along the way that a human stomach and a cow’s complex 4-compartment stomach function quite differently. If I’m not mistaken, the function of ruminants is to essentially create an environment for bacteria to flourish, digesting cellulose and other plant components, multiplying to ghastly numbers and then being digested via the small and large intestines.
Now, the doctor is certainly correct, as far as I can determine, about the fact that both humans and ruminants synthesize a lot of B12 via bacteria in the colon and that it’s essentially not bioavailable. Perhaps it has some other evolutionary function, such as seeding the soil with B12, as well as the bacteria that continue to synthesize it.
But the main head scratcher for me was: if all B12 in meat is a function of bacterial contamination from fecal matter, how about the high B12 content in a piece of beef liver (the highest) or a filet that has been well cooked? What, does the surface B12 from such contamination somehow burrow into the meat itself? I dunno? Does anyone?
But I also thought: waitaminute, surely with all those trillions of bacteria digesting plant matter in the rumens of sheep, goats, cattle, venison, buffalo…that surely some level of B12 has to be produced and if so, then it’s available for absorption in the small intestine. It would be odd if that turned out not to be the case. Well, fortunately, just a few minutes of Googling provided the answers at PubMed and Journal of Animal Science.
Apparent ruminal synthesis and intestinal disappearance of vitamin B12 and its analogs in dairy cows
Although cobalamin [Vitamin B12] was not the major form synthesized by ruminal microflora and, even if supplementary cyanocobalamin was extensively destroyed by ruminal microflora, based on calculations of apparent intestinal disappearance, cobalamin seems to be the major form absorbed in the small intestine.
And here, from near the end and summary.
The Excretion of Vitamin B12 by Dairy Cattle
Therefore, although the amount of vitamin B12 synthesized in the rumen is unquestionably very great, it is doubtful that the full extent of this action is often of importance to the ruminant on most rations, unless the amount metabolized and not recovered is also very great. On a ration devoid of vitamin B12, however, the rumen synthesis of this vitamin is unquestionably of great importance….
Rations containing either oats or corn do not differ significantly in their favorable effect on the rumen synthesis of vitamin B12.
So, as you all note I handled this one differently than usual. Clearly Dr. Seale is no Shiite Veg*n and distinctions ought to be made.
In other news, apparently famed activist George Monblot is no longer shilling for veganism: “I was wrong about veganism. Let them eat meat – but farm it properly.”
So there you have it. The nutritional and environmental case for veg*nism toppled, in one fell swoop.
Later: Well, I did have to drop in a comment.
Ruminants also synthesize significant B12 via bacteria in the rumen where it’s available to the small intestine, then hits the portal vein directly to the liver to be doled out to other organs and lean tissues. That’s why ruminant liver is the richest source of B12 on the planet. Clams are number 2, but there, we’re consuming the entire digestive tract.
I provide PubMed and Journal of Animal Science refs at this post:
Dr. Seale: “any B12 present in animal foods is only because of bacterial contamination”
On another note, I’m not sure I appreciate the distinction between plants contaminated with dirt (partially composed of rotted animal corpses and their waste, dirty hands & nails), and trace fecal contamination of meat or milk, both of which can be rendered safe through cooking methods and pasteurization (though when I drink it rarely, my milk is raw, whole, and un-homogenized).
Someday the veg*ns are going to see that the “paleos,” such as myself have the essentials right. It’s not about eliminating a core evolutionary food group but about eliminating the modern processed manifestations of non-food.
Whole non-processed foods from animals & plants does a body good (70 pounds lost and counting).
Dr. Seale’s response?
Richard – congrats on your weight loss! Even though I don’t agree with some of the tenets of the paleo Diet, it appears you’ve found a method that works for you, and weight loss is always a good defense against chronic disease.
Hmm, total honesty on the dietary front; i.e., that the improvement in body composition likely outweighs other factors he may not advocate — which is fine, it’s a mark of honesty with me.
But to not even address my core dispute? Either ruminants produce B12 for metabolic absorption, or they don’t. It can’t be both. I say he’s dead wrong. He should extend his honesty to a broader context.
More later: my further comment at Dr. Seale’s:
Thank you for your well wishes. Indeed, the honest approach for both the vegetarian minded, the paleo minded, or whomever, is to acknowledge that all people are different and that it’s hard to argue with n=1.
If only everyone would take responsibility for their own health as I have (and you, I’m sure), self-experiment, fine tune, and find what makes you look and feel good, none of this would need to exist.
But I do have to bring up my observation that while showing a lot of honesty in acknowledging that what’s working for me may be the best defense, you did not address my core argument in the slightest respect.
Doctor, you have stated that “any B12 present in animal foods is only because of bacterial contamination” and I have directly contradicted that assertion, with journal published references.
Should you not broaden your characteristic honesty to confront that? Moreover, I’m not just a muckraker. I have at least a dozen MDs who are fans of my blog, read it regularly, exchange emails with me and comment (there are a few in the last two posts). Some give my blog URL to patients, mostly diabetics, because paleo plain works for managing a broken metabolism (as does vegan or raw vegan..I acknowledge — I have a post about that, in fact).
It would be a shame for you to go forth under a paradigm based on a crucial error, wouldn’t it? I’m not saying that the fact that ruminants produce high B12 naturally — and they absolutely do — and not by industrial contamination invalidates veg*nism alone, but it is at the very least a very pesky fact to deal with, given that you are advocating supplementation which is certainly not anywhere in the evolutionary scheme of things.
I guess we’ll see.
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Over in one. Nice.
Anyway, can you clarify some more about the distinction of B12 found in the liver. Is there some mechanism being explained there which identifies how it is deposited in the beef liver?
Intuitively, I’d say the same way as for the rest of its meat and organs, via the bloodstream from absorption in the small intestine (after bacterial synthesis in the rumen). Concentration is likely higher in the liver because that’s the blood filter and I think the liver is very selfish.
Liver is not selfish, it is the mineral and Vitamin Store for the body.
That is why it is like a multi-vitamin multi-mineral food, and can be toxic in large quantities.
I meant that in a wry sort or way, Anand.
All these theory of Vitamin B-12 are bogus. Vitamin B-12 molecule has Cobalt in the center. It is a Organo metallic compound. So if there is no cobalt -no Vitamin B-12. For anaerobic bacteria to synthesize B-12 need cobalt. And that will come from Vegetation.
So only in the area of soil rich in Cobalt, the vegetation will have cobalt in it. And then after animal eat this grass, bacteria can synthesize B-12.
Now anaerobic bacteria are known to produce Methane and Hydrogen Sulfide. So synthesis of B-12 is also not viable hypothesis.
HArilal Patel email@example.com
From what I can find, bovine have portal vein function like that of a human (i.e. b vitamins are taken up into the capillary bed of the small intestine, hit the portal vein and shoot straight to the liver for processing and then into the blood for use in tissues) then it’s no surprise that the Liver is rich in B12. This of course makes the “b12 by bacterial contamination” interesting but irrelevant.
The liver is so very selfish, keeping most of the B12 for itself. Pig.
That is some kooky reasoning! Bacterial contamination, indeed.
Per David Csonka: Nice.
BTW I put the George Monbiot article on the PaleoHacks header. Thanks for head’s up.
All right, I went back to his website and the blogpost is a little less kooky, but very conventional and misinformed from an evolutionary perspective (isn’t almost everyone, though). The main kooky bit is how he tries to divorce the bacterial flora from the circle of life, and how he contends that our ancestors could have subsisted on an entirely plant-based diet and obtained plenty of B12 from the soil, though there is obviously zero evidence this ever happened in any human community. He also has an interesting definition of “antioxidant” and obviously does not understand there are antioxidants besides vitamin c et al, that we can make our own powerful antioxidants (such as serotonin or glutathione for example) from animal protein… He probably doesn’t know about K2 and he thinks fiber is important. I could go on and on. (saturated fat is bad when the first thing we do with any excess carbohydrate is make saturated fat out of it for storage!).
Yea, Emily, it really reminds me of creationists who use the same arguments I heard in the 70s, not taking into account that the knowledge has magnified tremendously (though it was plenty sufficient from the 1800s on anyway — big clue there).
This is going to crumble. Paleo trumps simply because it does not attempt to un-intuitively eliminate the core human food group that made us human: animal protein and fat. More and more people are coming forward, most recently Angelina Jolie, saying that a vegan diet “almost killed her.”
Their days are numbered.
O MY you know your Angelina Jolie tidbits well!
Did you know she does Muay Thai and Krav to get trained Salt and the sequels…? (she’s also purportedly quite a bonobo *haaaa ah*)
Grass fed lamb’s liver, twice a week. End of.
One last nitpick – I dislike the negative connotation of the word “contamination” as if animal bacterial flora is disgusting or dirty. I challenge Dr. Searle to see how long he could thrive without his own “bacterial contamination” in his gut.
To clarify, Dr Dees, that was my first thought and I was about to go off on it in my infamous invective. A closer reading, including the comment led me to believe he doesn’t mean that gut flora is contamination, but that food, ie meat, is physically contaminated with fecal matter.
…Which in a sense is almost worse — to believe that the entire meat eating world gets their b12 needs from contaminated meat rather than meat that has been metabolized biologically with b12. Pretty outlandish and reaching.
Yes, I see that now that I’ve re-read his post. But I think it didn’t sink in the first several times (even after you explained it in your post) because it shows no sense at all, and the rest of his post is entirely sensible from a conventional wisdom perspective, though nearly completely wrong.
He’s what I see a lot of on the internet: He’s educated in his field and assumes he’s educated in all others, especially something “simple” like agriculture/food processing. Sorry, not so much.
The bit about B12 and slaughterhouses is idiotic. Does he honestly think that if you butcher out a cow without breaking the gut (which is the correct way of doing it) that there is no B12 in the meat?
And the questions he posed to the student? Those are 6th grader from the city on a class trip to the farm type questions.
Ye, gods, save me from the vegetarian who thinks they know anything, and then signs their posts saying they are a “health educator”. Gaahhhh!
I just answered his questions in comments on his blog, and asked him just one.
His non-answer is a classic Randian “blank out”.
And apparently, he’s now decided not just to disable comments, but delete all the ones that were posted. Classy.
Hah. I stick my foot in it sometimes on my blog and it is tempting to delete the whole thing. I never pretended to be an expert in ruminant digestion, though!
What an unmitigated coward. I suppose ‘inconvenient truths’ make him uncomfortable.
Unfortunalely, with one change he is able to publish something he well knows is a lie so he can prop up his ego and push his agenda. Future visitors to the site will trust his advice because he is a doctor and co-author of ‘nutrition’ books.
Peter from Hyperlipid should know a thing or two about this.
Peter knows at least four of five things about everything. 🙂
It occurs to me that his post betrays the essence of the flawed supposition of vegans – that humans can be ruminants without rumens, and that a obligate plant eating animal has the same gut an omnivore would.
I have a small number of regrets in life. One of them is that I found a pubmed paper where a vegan-parented infant was dying of B12 deficiency (there are many, many such reports) but in this one the parents refused B12 therapy, as you obviously would if you are a True Believer. The infant was saved by simply nasogastrically feeding him/her her own faeces, so allowing bacterially derived B12 from the colon to be absorbed by the lower small intestine, not something which happens normally.
The message is clear that a true vegan NEEDS to consume faeces, preferably their own. Just talking cr*p is not enough. Now you know what a B12 replete vegan gets up to in the privacy of their own bathroom.
How can I have lost such a gem? Mea culpa, mea maxima culpa…… Peter hangs head in shame.
Horribly hysterical. I’ll laugh but only to keep me from wallowing in my lament for the humans who know nothing but self-destructive folly.
Shame on you Peter. *haaa aha*
If humans want to be herbivores they should do as herbivores do! Consume cr*p…
like my guinea pig! Mother elephants feed their feces to their babies.
Really must blog about the Paignton Zoo Joke-umentary from a few years ago….. Let’s get some vegans on a real Gorilla diet….
OMG I think I’m getting silly. Too long on call!
Will stick hard to being a fat-o-holic carnivore thank you very much!
In my profession when one’s brain is forced to do uncomfortable cartwheels around another person’s reasoning to make sense of it, the first thing you are trained to do is check for a psychosis. The definition of a delusion, after all, is “a fixed false belief.”
There are exceptions made, of course, for cultural constructs or religion. Veganism falls in that rubric.
At least he very sensibly calls for B12 supplementation (though he seems to lament the fact that our depleted soils somehow are no longer worth eating outright – one can find plenty of crap in all sorts of places, as we well know)
“He’s what I see a lot of on the internet: He’s educated in his field and assumes he’s educated in all others, especially something “simple” like agriculture/food processing. Sorry, not so much.”
I agree, a lot of doctors are like fathers……”it doesn’t matter if i’m right or wrong…you have to listen to me..I am your father”
i don’t see the point in arguing about vitamin B12. most people get plenty of it from multivitamins, so who cares whether or not we’re getting enough of it from the diet? there are more important dietary issues to worry about
Because getting nutrients from anything other than real food is an inferior solution. More importantly, because it matters when people are full of shit, and it matters even more when they dishonestly refuse to admit their own ignorance, particularly when people are harmed by relying on their bad advice.
How on topic!
“when people are full of shit”
The mark of a B12 replete vegan. OMG I just love it!
Okay, I agree, not funny really.
There is something really profound lurking in the background to this rather ridiculous conversation. We are all “full of shit” on some level (being humans who have to guess our way past facts we cannot always see), and some of us (because of certain choices we have made vis-a-vis lifeway) actually need to eat the crap that the rest of us find “distasteful” (to put it mildly) and unnecessary. All I can say is that if my n=1 experiment had me eating shit, literally, I would want to change something.
You’re full of shit. And….easiest way to do that is how the natural vegans do it, nothing to buy. See Peter’s video a few comments above. And what the he’ll, celebrate.
Eating vegan shit is, well, vegan!!! Go Vegan!!!
As mentioned by damaged justice, the Doktor removed all comments from his post and closed it. Had he removed the entry entirely I would have thought him only an honest pussy. But now he incurred my wrath.
In video, tomorrow. Invective will be off the charts. The Bullshit horn will be employed.
Ruh roh! Yes, it is a special set of huevos (curiously unreflective!) to leave the unaltered entry up even after admitting he was wrong about basic biology. Eades would start quoting Shakespeare and tales of idiots and sound and fury here, but I do think that dignifies the situation too much.
Did he admit it? I didn’t see that. I onlybsaw evasion. If he actually admitted being wrong I might have to rethink.
He wrote that it didn’t matter. He still would not advise his patients to eat meat due to the health risks. I asked him what him was wrong with meat.
‘Primal Toad’ then posted:
“Medical research bears out that a vegetarian diet comprised of a variety of whole grains, fruits, vegetables, beans, and nuts/seeds is the healthiest diet on the planet. There is no macro- or micro-nutrient that can be obtained in a healthier manner than from those food groups – this includes iron, calcium, and protein.”
And so what do you have to say to the research that proves the paleo diet is the healthiest on the planet? What do you say about the harmful effects of gluten? What about antinutrients in grains?
What about EPA and DHA? Since you are a doctor you must know that the only source of these 2 essential fatty acids is from animal products. And, the consumption of these fatty acids lead to our large brains.
What about the simple fact that the human has a small stomach – a stomach that evolved from eating lots of animal foods. A cow has 4 large stomachs and is able to effectively digest the cellulose in the grass it eats. We then eat the cow which is full of nutrition. We are able to easily digest the meat from the cow. But, eating that much spinach or other greens? Not possible.
And the Doc Responded:
Primal – It’s clear that you have become convinced via the reading you’ve done that Paleo is the way to go. Is it ideal? Not based on the full body of peer-reviewed, evidence-based medical research. Is is better than the SAD? Yes. So, if Paleo is the plan that makes sense to you, then go for it. Free country. You’re other comments and logic – sorry, they’re completely off the mark and/or inaccurate. Keep on reading, and learning – go to PubMed to do your searches. And keep an open mind. I’ve done this in evaluating Paleo, but unfortunately the studies haven’t convinced me it is the best way for modern man to eat – therefore it isn’t what I recommend as the ideal. It’s not an attack on Paleo for me to not recommend it – it’s my freedom to choose, just like yours.
Shortly after it appears he picked up his toys and went home. Or rather told everyone else to go away. Well, you know what I mean.
I was referring to when he said “I do not dispute that cows can absorb some B12 via their rumens” (or something like that) … Blah blah blah “doesn’t change the fact”. Blah blah blah plant based whole foods etc better for “modern humans”.
Hi Richard, thanks for this, apart from being quite funny, the matter is most fundamental. One of the reasons I gave up vegetarianism was that I did more reading about omega-3 (and that linseed oil is not the way forward). This was THE argument for me that we were meant to eat meat as well. Regarding B12 I used to eat a lot of fermented stuff and I guess cheese had some of that as well. Plus non-sterile fruit and veg. But without the neolithic fermentation the options would be:
1. Eat more rotten vegetables. I think it would work, particularly with some soil added.
2. Eat contents of ruminants’ stomachs and intestines. The Innuit eat the fermented and part-digested moss from reinder gut (they even used to eat the feaces!). Would that pass the vegan test? This was probably common back in the old days.
3. Eat decomposing meat. Scavenging was most certainly common.
4. Eat insects/worms incl their digestive tracts.
5. The molluscs you mention.
6. Eat liver/meat.
7. Eat sh*t.
The first and the last options would still be avaialble for vegans and should not be dismissed. Second option would also be vegetarian, though not vegan. Even honey is not vegan.
And re sh*t, I suppose the Paleo folks could have their hands dirty: large herbivores’ droppings could have been used for burning to heat the caves 🙂
Which also might explain why many meat eating humans have B12 deficiency: few people eat liver muscle meat has less b12. Also non-ruminant meat, e.g. pork, would have less. Of course, with high carb diets also more vit B12 is needed, though I am not sure it would apply to B12.
But there is one thing I can’t figure out: how do birds get their B12? And they need a lot of it for eggs. The leaf eating hoazin does fermentation in his foregut, but as far as I know this is not the rule in birds. Crows do eat herbivore droppings, but I can’t see this as a universal solution. Perhaps insects then, which would explain why chicken feed has b12 in it…
One of my favorite parts of the “Vegetarian Myth” was Keith’s description of her chickens eating every small animal that came across–squirrels, rodents, snakes, every type of insect–and of course, each other. That would explain how chickens can feed themselve sand get B12 without needing chickenfeed. I don’t remember anything about pecking at feces.
Chickens that are pastured in a field previously used to pasture cattle like nothing better than tearing apart cow pies for the maggots, thereby helping control flies while at the same time getting their needed B12 (and other nutrients) and contributing fertilizer to the field.
Joel Salatin, in his recent book “The Sheer Ecstasy of Being a Lunatic Farmer” tells of some of his chickens that were not pastured that developed a crippling problem called ‘curly toe”, caused by vitamin B deficiency. He initially solved by feeding the chickens liver. Subsequently he used vitamin fortified chicken feed in lieu of liver.
Antacids can mask symptoms of serious disease. Antacids also decrease the absorption of vitamin B12 .
Just so everyone on comment notification knows, Dr Seale reinstated all the comments. Hey, we’ve done things we later thought better of, which obviously did and he took the next step which was to correct it. While the core differences still exist there are also significant areas of agreement, such as the SAD. At any rate, I salute the doctor for making things right.
I love the way you directly get to the point,inspired
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So, ruminants have special ways of getting all the B12 produced by colon bacteria back into their systems and we can eat it as meat and milk. But there are still things I do not understand. For example chickens, eggs are also supposed to be high in B12, how does it get there? Also, fish is supposed to be good but we remove the entire gut before eating – how do they get B12 into their flesh?
B 12 IS an animal product. All b12 IS an animal product.