huh?Quote:
Factsheet? Let's call it an assumption-sheet lacking a lot of essential info, and we agree. :)Quote:
wht do you mean?
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huh?Quote:
Factsheet? Let's call it an assumption-sheet lacking a lot of essential info, and we agree. :)Quote:
wht do you mean?
They write: "The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements."Quote:
herbwormwood
As a start - or.. before we start :), please ask them what their definition of 'reliable' is, how many plants of the almost 300,000 plant species that has been tested for B12, and how the reliability has been tested. Post the reply here, and I'll get back to you. ;)
They claim that there is is no harm in exceeding the recommended amounts or combining more than one option, even if they potentially are giving this advice to vegan newbies coming straight from a lifestyle containing both a lot of animal products daily PLUS vitamin supplements in all shapes and colors. It would be more fair to say that there are disagreements re. the implications involved in taking too much B12.
I have been led to believe that not all plant sources of B12 are bioavailable. Here's another site about B12 which discusses this.
http://www.veganhealth.org/b12/meas
I have commented on the veganhealth.org approach towards various B12-issues in several other threads over the years, and will try not to repeat myself.
On the site you refer to, they write that 'The only reliable way to determine if a food is a source of active B12 is to test various batches of that food to see if it reduces methyl malonic acid (MMA) levels in humans.'
I'll stick to repeating my question: how many plants of the almost 300,000 plant species have been tested for B12? Plus - under which conditions have the plants been tested? Fresh? Organic? Have the plants been exposed to eg. chlorinated water during or before the test?
If 100 non-processed, fresh, organic out of 275,000 possible plants have been tested for reliability under defined, controlled premises, that's still only 0.04% of all plants. Most scientists performing B12-studies haven't been interested in measuring B12 in plants, because most people get their B12 from animal products. A lot of comments about B12 have been made by referring to a the writings comments made by the a certain anti-vegan crusader named Dr. Victor Herbert, who admitted that he based some of his conclusions on testing only - what was it - two plants? And as far as I remember (but I may be wrong), he didn't say anything about under which conditions the plants were tested. Fresh? Dried? Cooked?
If the tests has not been done using reliable methods, or on plants that have been exposed to something that may kill the B12 in it, and/or only 0.04% of all plants have been tested, how can someone say that "The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements". Why not at least say that they don't know/that reliable information isn't available?
I think most people don't like being preached to, but if a potential or exisiting vegan visits vegansociety.com or veganhealth.org, they deserve a presentation of the B12 issues in presented in a way that doesn't look like it has been written from the perspective of a meat eating hypochondriac. :)
Why don't they inform their visitors about the various tests (like this one) that show that showing that 'as many as 40 percent of healthy men and women have low levels of B-12 -- and those levels were deficient even though the people were eating diets that has as much as three times the recommended daily intake of this critical vitamin.' Why don't at at least try to scratch the surface, and tell people that your B12 levels is dependent on a lot of things, not only how much you consume.
I don't know how many visitors these sites have, but their lack of enthusiasm towards giving a balanced, complete picture of the vegan/B12 issue may be a main reason if people leave the their sites with the same lack of enthusiasm and that their 'info' represents.
I just came across an interesting article written as a comment to someone who has written another article trying to debunk some B12 myths. The writer, Stephen Walsh, insist that the articles that he comments (and which are meant to debunk myths) creates other myths instead (and I agree).
I may lack some information, but it may look like the comment from Stephen Walsh also contributes to keeping myths alive, or at least, his article isn't backed up with studies documenting that what he says is based on facts.
The article is here: Stephen Byrnes: A myth-making "debunker"
Here are a couple of quotes from Stephen Walsh's comments:
Quote:
Dried nori contains mostly inactive analogues and has been shown to interfere with B12 metabolism if eaten in very large quantities (40 g per day). In normal amounts, however, it causes no problem provided adequate dietary sources of true B12 are consumed.
The only test I've seen on the relationship between active B12 and passive B12 analogues in faeces showed that 95% of the B12 analogues in B12 were not active. There are also a study suggesting that high amounts of B12 analogues may not be a problem when it comes to curing B12 deficiency. Are there any controlled studies articles at all, that has been done on primates eating faeces vs. primates that does not? Are there any studies showing the ratio between B12 and B12 analogues in their faeces?Quote:
Fermenting bacteria in the large intestine certainly do produce B12 (along with plenty of inactive analogues). Many of our primate relatives eat faeces and may obtain much of their B12 from this source.
If 95% of the B12 in their faeces are passive B12 analogues, would that be a problem, or would it not? And what about all the B12 and B12 analogues found in water, grass, bark, moss, leaves... why is this B12 less interesting than the one found in faeces and insect remnants?
There are also studies suggesting that B12 is better absorbed in animal products ('An animal study found that a natural food complex vitamin B12 was absorbed 2.56 times more into the blood and was retained 1.59 times more in the liver than isolated USP cyanocobalamin '*). Studies comparing B12 absorbed from plants and from supplements are rare, but there are many articles that question if the B12 and other nutrients taken from supplements are as reliable as some people give the impression of. IMO supplements isn't the 'perfect' solution, but may be a needed substitute.Quote:
B12 from fortified foods or supplements (directly harvested from bacteria) is at least as reliable and absorbable as B12 from animal products.
It's correct that it has been documented that fortified foods and supplements are more effective sources of B12, but I'd strongly prefer to present B12 info in a way that includes support for the fact that B12 (and B12 analogues) actually can be found in plants, rather than the glorification of using supplements (without explaining why this may be needed for people on any diet). We don't need to keep the myth about primates faeces and insect remnants being so important B12 source for primates, and we don't need to make assumptions based on the many unanswered questions about B12 analogues. If a 'fact' isn't documented, it is an assumption, which is very close to a myth in this context.
Again, Walsh is (un-intenionally) supporting the myth that there were/are no B12 in plants. He seem to base his opinion on a statement about faeces from animals and remnants of insects... which would have been very interesting if he had posted links to studies on active B12 vs. B12 levels in faeces and insects, studies on wild, plant eating animals that did not eat feaces, and studies that discussed when B12 analogues are problematic and when they are not. Since B12 analogues are found 'everywhere', maybe they aren't as bad as some people think, and if they are not, why always discuss the B12 analogues in plants as so problematic? There are countless statements about algae and other plant foods containing B12-analogues that interfere B12 metabolism, but the people who write this stuff are often the same people who say that primates got their B12 from faeces, and not from plants, even if faeces may contain a much higher ratio of analogues than the plants, soil and water these animals ingest.Quote:
Some primates eat faeces, some deliberately eat insects and all consume remnants of insects incidentally with the fruits, leaves and shoots which form the bulk of the diet of our great ape relatives. All get their B12 from bacteria.
Modern humans, of all persuasions, embrace the benefits of sanitary food preparation and therefore lose the B12 sources that have sustained our fellow great apes for millions of years.
For an average meat eater (or vegan), doesn't this only look like one avoids discussing whether the vegan diet is natural or not by inventing a new definition of 'natural'?Quote:
Getting B12 from fortified foods or supplements is an entirely natural and commendable choice for humans to make.
Please don't get me wrong, I think the Walsh article contains a lot of good stuff, but I think vegans - just like others - may keep old myths alive without actually noticing it.
Here's a great online talk from Dr. Michael Greger, he goes into length about vitamin B12. The lecture has really important nutritional information for vegans and I suggest everyone listen. I learned a great deal from it. You can view in broadband or download in MP3 format. There are some other good talks on the site as well:
http://www.drgreger.org/talks/