Thursday, March 16, 2017

Meta-analysis Concludes Vegans Virtually Destined for B12 Deficiency Disorders Despite Supplementation

Obersby et al. reviewed  17 studies including 3230 subjects and found that only 2 studies reported that vegans had concentrations of plasma homocysteine and serum vitamin B12 similar to omnivores.  The other 15 studies found B12 deficiency and elevated plasma homocysteine to be the "normal" state for vegans.

Most defenders of veganism will argue that this problem can easily be solved by taking supplemental vitamin B12.  However, the authors refer to some interesting research on vitamin B12 supplements:

"The present review reveals that there is only poor evidence available of vegetarians consuming vitamin B12 supplements and/or vitamin B12-fortified food and beverages. However, supplements, fortified food and beverages normally contain the less efficient cyanocobalamin form of vitamin B12, which when it enters the bloodstream must be converted to methylcobalamin(62), the only form of vitamin B12 that has a methyl donor that is required to neutralise homocysteine(63). It takes 4–9 weeks for this conversion to take place(64), assuming there are no disruptions by genetic factors, age-related problems and metabolic obstacles that may be present. Furthermore, research suggests that vitamin B12 that is not dissolved in the mouth will not (up to 88 %) be absorbed(65), due to the lack of R-binder mostly obtained from saliva, which is required to start the absorption process. The aforementioned study indicates that supplementation with cyanocobalamin can be poorly absorbed, which will have little or no effect on raising vitamin B12 levels."
Indeed, Crane et al. (reference 65 in above passage) found that oral supplementation of B12 did not raise serum B12 unless the tablet could be readily dissolved.  Reference 64 is a paper entitled "The coenzyme forms of vitamin B12: towards an understanding of their therapeutic potential" by Kelly [here].

"The compound most commonly referred to as vitamin B12 is CN-Cbl; however, this molecule does not occur naturally in plants, micro-organisms, or animal tissues. CN-Cbl has a cyanide molecule at the metal-carbon position and its cobalt atom exists at an oxidative state of +3, not the biologically active +1 state. In order to be utilized in the body, the cyanide molecule must removed and eliminated through phase II detoxification. It is thought that glutathione (GSH) might be the compound performing the function of decyanation in vivo, since glutathionylcobalamin (GS-Cbl) has been isolated from mammalian tissue. If, in fact, GSH is needed as a cofactor to activate CN-Cbl to the coenzyme forms of vitamin B12, clinical situations characterized by decreased tissue levels of GSH might be expected to result in functional deficiency of vitamin B12, even in the presence of adequate plasma or tissue levels of the cobalamin moiety (typically labs are looking only for a cobalamin moiety and do not differentiate between CN-Cbl and the active forms of vitamin B12)."

Apparently, one can take CN-Cbl, a.k.a. cyanocobalamin through supplements and fortified foods, and thereby raise your blood B12 level, yet remain functionally B12 deficient because CN-Cbl is inactive.  Further, we do not use the basic cobalamin molecule produced by micro-organisms, but the methylcobalamin (MetCbl) and adenosylcobalamin (AdeCbl) found only in animal tissues:

"Although the basic cobalamin molecule is only synthesized by micro-organisms, all mammalian cells can convert it into the coenzymes AdeCbl and MetCbl. OH-Cbl, MetCbl, and AdeCbl are the three forms of cobalamin most frequently isolated from mammalian tissue. However, only MetCbl and AdeCbl actually function as cofactors in human enzymes. AdeCbl is the major form in cellular tissues, where it is retained in the mitochondria. MetCbl predominates in blood plasma and certain other body fluids, such as cerebral spinal fluid, and, in cells is found in the cytosol."

As already stated, apparently the body can convert CN-Cbl to the active forms, but the process takes 1-2 months, and may be disrupted by genetic factors, age-related problems, and metabolic issues.  Kelly lists a number of problems that may develop in the absence of sufficient active B12, including liver disease, sleep disturbances, elevated homocysteine and methylmalonic acid (common in vegans), anemia, male infertility (low sperm concentrations, counts and motility, which have been reported common in Adventist vegetarians),  eye disorders, anorexia, and cancer. 
"While information is very limited, both AdeCbl and MetCbl might eventually be shown to have a supportive role in the prevention or treatment of cancer. A significant body of experimental evidence suggests a deficiency of vitamin B12 can enhance the activity of various carcinogens [17].  Experimental results also indicate a link between alterations in the intracellular metabolism of cobalamin and the increased growth of human melanoma cells [18]."
 Who is investigating the role of B12 deficiency in the genesis and promotion of cancer?

In view of all of this data,  Obersby et al. conclude that in the absence of improved delivery systems for "vegan" B12,

"The present study confirmed that an inverse relationship exists between plasma tHcy and serum vitamin B12, from which it can be concluded that the usual dietary source of vitamin B12 is animal products and those who choose to omit or restrict these products are destined to become vitamin B12 deficient."
In other words, in the absence of ideology and technology, it appears that humans have an evolved nutritional requirement for animal products to obtain the metabolically active forms of vitamin B12.  If you eat a vegan diet, you should supplement with methylcobalamin, which is better retained and utilized than cyanocobalamin, although it is unknown at this time whether this will adequately address all vitamin B12 requirements in the absence of dietary animal products which also contain adenosylcobalamin. 



8 comments:

Charles Grashow said...

" it is unknown at this time whether this will adequately address all vitamin B12 requirements in the absence of dietary animal products which also contain adenosylcobalamin. "

How can you continue to insist that veganism is "healthy"?

Don Matesz said...

What is your evidence that I am "continuing to insist that veganism is healthy"? In this very blog I am saying exactly the opposite, with the sentence you just quoted. All of this year my posts have been more or less anti-vegan. I do not "insist" that veganism is healthy, nor do any longer I believe it is so, nor do I recommend it to anyone now or in the future. And I am not even eating a vegan diet myself.

swampf0etus said...

I must admit, I thought Charles jumped the gun with that comment.

But, wow, you seem to have completely reversed your beliefs since your 5 year vegan blood results in December. I could perhaps understand you advocating a little lean meat of fish in the diet, but you seem to have gone quite anti-vegan. I thought your tweet the other day about a vegan mountaineer dying whilst climbing Everest was a little silly. What was the point of this? Does this prove vegans should eat meat? Do all the omnivores that have died on Everest prove that meat shouldn’t be eaten? And did you know that the day before that mountaineer died, another vegan successfully reached the summit? (http://www.onegreenplanet.org/news/vegan-successfully-climbed-mount-everest/) I’m not sure why you so quickly changed from being vegan to vegan basher so quickly.

Personally, I’m only just testing the waters with veganism. I’ve been doing it for the last six months, but more strictly since January. I started for health reasons, rather than ethical, after realising the fallacies of my previous LCHF diet. But I’m also concerned about the environmental impact of meat production. I’ve found your recent posts very interesting and something to think about and explore, as I’m keen to not swap one ideology for another.

I’m interested to know what you now believe is the safest middle ground between veganism and omnivory, both for health and the environment?

Don Matesz said...

"Better to turn around than to continue going astray." That's a paraphrase of an old European proverb.

" I could perhaps understand you advocating a little lean meat of fish in the diet, but you seem to have gone quite anti-vegan."

I published Essential Macrobiotics (https://www.amazon.com/Essential-Macrobiotics-Universal-Health-Prosperity/dp/1535363371/ref=sr_1_2?ie=UTF8&qid=1490110434&sr=8-2&keywords=Essential+Macrobiotics) on Nov 26, 2016. That's before my blood test. If you read it you will find that in that book I already gave my updated view that humans are not adapted to vegan diets. I stated on page 63:

"In summary, humans appear best adapted to a varied, primarily plant-based diet supplemented regularly with fish, or with meat or eggs from wild or pastured birds, and perhaps occasionally with meat or milk from wild or pastured animals."

Since then as recorded in this blog I have been convinced by even more evidence that humans are biologically adapted to meat-eating, making veganism possible only with supplements and probably only long-term only for a very very small portion of the population even with supplements, if at all. Simply, veganism is an experiment, which will gradually reveal what animal-based nutrients humans require.

As with B12, we don't know everything we require and we only discover it by removing the sources from our diet, developing deficiencies and then searching for the item(s) that were absent. Since November I have come to the conclusion that we have sufficient evidence (IMO) that MOST humans require multiple animal-based nutrients for optimum function or growth and development, at least at critical stages (pregancy, lactation, childhood, probably fertiity). This doesn't exclude SOME people doing OK or even thriving. Again, its just the same as this: Almost all people can learn to dribble a basketball, but only a very tiny percentage of the total population will be so well adapted to the demands of basketball that they will become pro players. Almost all people can "try" a vegan diet for a period of time, and even "succeed" for a period of time, but only a tiny percentage will have low enough requirements for animal-based nutrients that they will be able and willing to thrive on it long-term.

Don Matesz said...

Remember, thought processes and learning are invisible to outsiders. It may seem that I "suddenly" became anti-vegan, but the process of changing my opinion took place over the course of about 6-12 months, resulting from both my personal experiences on a vegan diet and gaining more knowledge of a) evolved genetic adaptations to meat-eating, and b) relatively poor performance of SDA vegans, especially female vegans, in overall mortality and cause-specific mortality.

Before my 5 year vegan blood test, I was concerned with my very slow recovery from my knee injury (more than 18 months), my very slow progress in strength training, gradually increasing loss of visual acuity (having never needed glasses in my life and knowing that this does not happen among hunter-gatherers), emergence and increase in digestive issues (acid reflux and bloating) and some other signs of deficiency (e.g. brittle nails). Then I took the 5-year blood test showing the below normal phosphorus and globulin, and after that, I took an oral zinc challenge test which I failed, indicating a 70% chance I was zinc deficient (which I suspected since I was tracking zinc intake and found it difficult to meet the dietary requirement for a vegan on a continuous basis).

Don Matesz said...

"I’m interested to know what you now believe is the safest middle ground between veganism and omnivory, both for health and the environment?"

I assume you mean, how much animal food does one need to be healthy, yet also limit one's impact on the environment?

I can't completely answer this question here because I believe that the claims that animal agriculture uniquely causes environmental damage are questionable to say the least. In fact, much of the environmental costs and damage attributed to livestock is not due to the livestock themselves, but to the growing of feed grains fed to the animals. Stop feeding them grains, and a lot of the costs would be reduced.

Agriculture itself appears to have been driving "climate change" since its inception: https://www.nelson.wisc.edu/news/story.php?story=1862

Mono-cropping is driving soil loss: https://www.scientificamerican.com/article/only-60-years-of-farming-left-if-soil-degradation-continues

Third, agricultural food production has been and will continue to be a primary driver of human population growth (more food per acre => more people), and human population is the main "consumer" of resources. Absent agriculture the human population would be much much smaller and we wouldn't have any environmental issues related to livestock (which were plentiful e.g. in the U.S. long before CAFOs). Not enough space here to share all the data.

I can't say I have the final answer to your question, but as I pointed out in Essential Macrobiotics, studies of several long-lived populations (Okinawa, Abkhasia, Koreans) appear to indicate that diets supplying 15% of energy from animal products do not reduce life expectancy or increase risk of degenerative diseases and SDA data actually suggests that at least for women, this level of meat intake may actually reduce all-cause and cause-specific mortality, provided it is in the context of a predominantly (i.e. about 85%) whole-foods plant based diet. However, I suspect the "safe" level of animal food consumption may be somewhat higher (e.g. ~20% of calories( IF again the rest of the diet is fruits, vegetables, nuts, and soft seeds.

But I believe we all need to learn to use our built-in guidance systems to lead us to the best answer for ourselves, rather than relying on "experts" and so-called "reason" since these methods have proven to take us to the brink of destruction.

If humans had required experts in modern science and "ethics" to discover the best foods to eat for health and fitness, our species would have been extinct long before these experts in this science even existed. No other species needs a dietitian to know how what natural foods to eat or in what amount.

After many years of trying to "figure out" the best diet using science and reason, I come very recently to believe that every human has an innate ability to find his/her dietary way, if the food choices are limited to what Nature provides even if humans don't do any controlling of food production. Nature provided us with the senses of taste, smell, vision, and satisfaction specifically to enable us to make the best choices from among the foods Nature Itself provides independent of agriculture.

I am working on a book on this. Enough said for now.

Don Matesz said...

Just to emphasize the point, I don't think I have the final answer to your question, only am pointing to evidence (longevous cultures) indicating that people can consume ~15% of energy from animal foods and achieve high resistance to degenerative diseases and great longevity. However I am not convinced that this means any higher animal intake is harmful. There are other aspects of the lifestyles of these longevous cultures that may be as important or more important to their success, such as high rates of stable marriage, childbearing, frequent close contact with Earth, farming lifestyle, more or better sleep, stronger social ties, and others. I think we tend to focus on diet because it may appear easier to manipulate in our "civilized" situations than these other factors. But in focusing on diet we may be missing more important boats.

Shameer Mulji said...

"In fact, much of the environmental costs and damage attributed to livestock is not due to the livestock themselves, but to the growing of feed grains fed to the animals. Stop feeding them grains, and a lot of the costs would be reduced."

Completely agree.


"studies of several long-lived populations (Okinawa, Abkhasia, Koreans) appear to indicate that diets supplying 15% of energy from animal products do not reduce life expectancy or increase risk of degenerative diseases and SDA data actually suggests that at least for women, this level of meat intake may actually reduce all-cause and cause-specific mortality, provided it is in the context of a predominantly (i.e. about 85%) whole-foods plant based diet."

When you mention whole-foods plant-based diet, does this include whole grains and legumes or strictly roots, tubers, non-starchy vegetables?