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New research on selenium

Johnmac

Senior Member
Messages
756
Location
Cambodia
Greg from B12Oils has new data on selenium, which could interest anyone who uses it, or anyone who uses B12 - for which Se is an essential co-factor.

I asked him if he would mind if I pasted what he emailed me here, & he said no. So here it is:


It is not so much what you eat, but where it was grown that may be important. Thus, Australia, NZ, and UK have been exporting soil selenium for years now, and so much of the produce, and probably worse if it is "free-range", can be deficient in selenium. Thus, in the UK selenium intake in the population is only half the RDA, in NZ it is only one quarter. Data in Australia is varied.

You need about 6 eggs, 1 lb of chicken, or lots of lamb to get your RDA. Tuna, ham and shrimp are better sources (and that is in the US where selenium levels are high).

RDA is about 55 ug. Fish has 12-60/100 gm, meats 5-40, and eggs 9-40 per 100 g, in Australia, but it would be regional, and depend upon whether they are battery fed or free range (battery fed would likely have more). This was in 2002, so I would guess less now. I would switch [from lamb] to pork.

And in a second email:

Yes the selenium problem. This appears to be really bad in countries such as NZ, Britain, Ireland, Wales, Sweden, Norway, and many northern and eastern European countries. Curiously not around the Mediterranean (as far as I can tell). It would be a hoot if the so-called benefits of the Mediterranean diet were actually due to much higher selenium in their food. If you want to post it on PR, and mention that it was in discussions with me that is fine. If we can wipe out CFS/FM, then you and I will have done something useful for society. Only diabetes, AD, ASD, PD to work on next, all of which seem relatively simple.

I find the selenium story fascinating because it would potentially represent one of the most powerful single nutrient deficiencies that there is, arguably as important as B12, but also it has a huge role to play in B12 cycling through its activity in making functional B2. FYI there is only about 40 years of selenium left to be mined in the world (according to a paper I found). Won't that be interesting.

The level of selenium intake in the UK appears to be halving every 10 years, so it is a big problem. Se deficiency would also cause globesity, as too B2, iodine, or even molybdenum deficiency. Similarly they would all cause an increase in the rates of dementia. Unfortunately AD Australia seems completely oblivious to the fact. Similarly increase the rates of ASD.

Se deficiency doesn't appear to much of a problem in the US where intake is way above the normal, which is why selenium supplementation studies haven't worked in the US, but yet have in the UK. For some reason the Cochrane reviews don't appear to take this into account.

BTW in the past Greg has emphasised that brazil nuts don't, after all, contain the right type of Se - so are no use as sources of Se.

Needless to say I can't answer questions on the above, as I'm just passing on someone else's research.
 

Hutan

Senior Member
Messages
1,099
Location
New Zealand
BTW in the past Greg has emphasised that brazil nuts don't, after all, contain the right type of Se - so are no use as sources of Se.
:eek: (having just eaten my daily two brazil nuts...)

Does anyone have any more information on that?

This study from New Zealand's University of Otago suggests that the selenium from brazil nuts is showing up in the blood.

Prof Thomson and colleagues carried out the first-ever study to look at how much selenium people can obtain from brazil nuts and the resulting levels of antioxidant activity in their blood. Their study appeared recently in the American Clinical Journal of Nutrition.

Sixty volunteers were tested over 12 weeks. They were divided into three groups, one of which ate two brazil nuts a day, while the other groups were given either a 100 microgram selenium supplement or a placebo to take daily.

The results showed the blood selenium concentrations of the brazil nut group were up by 64.2 per cent, the selenium supplement group's increase was 61 per cent and the placebo group 5.3 per cent.

The results showed that including a couple of brazil nuts a day in the diet could ensure a greatly enhanced selenium status without needing to fortify other foods or take supplements.

Prof Thomson said that while New Zealanders' low selenium intakes needed addressing, too much of the micronutrient could be toxic.

"People should be careful to limit themselves to no more than a few brazil nuts per day, otherwise selenium could potentially accumulate to toxic levels in body tissues."

The literature does warn repeatedly that there is a sweet spot for selenium levels - too much or too little are both bad.

http://www.otago.ac.nz/news/news/otago082203.html
Otago’s Department of Psychology co-author and study lead Dr Tamlin Conner says the research reinforces links between both low and high selenium status and adverse health effects in humans – including on mood, which is her main area of expertise.

“New Zealand has a well-known history of low selenium intake, with many people having intakes below what is required for maximum antioxidant defences. The average blood-serum selenium concentration observed in our study was below what is required for maximum glutathione peroxidase activity, so this suggests many young people in the South Island have intakes of selenium that are too low for optimal selenium status, and could benefit from increasing intakes.”

New Zealand soil is low in selenium and so locally grown foods tend to be low in selenium. This is the main reason why the selenium intakes of New Zealanders have historically been amongst the lowest in the world.

Changes in dietary patterns to increase selenium intake without risk of adversely high intakes should be encouraged – supplementation is not recommended because of the risk of excess intake.”

Safe ways to ensure a good selenium intake without the risk of consuming too much include choosing breads made with whole grains, and increasing the consumption of other high selenium foods such as canned fish, nuts and seeds, poultry, and eggs. Brazil nuts are a particularly rich source of selenium, and one or two brazil nuts per day could safely increase selenium intakes without risk of too high an intake.

Selenium is obviously not the silver bullet - people in the US generally have high levels of selenium and they still get ME.
 

Critterina

Senior Member
Messages
1,238
Location
Arizona, USA
Rice is often high in selenium because of where it's grown. I used BlueBonnet Multi-minerals with Boron, which has about 146% of the RDA and my selenium tested too high - out of range. And I wasn't eating rice. Selenium causes birth defects (particularly in frogs in the rice paddies in California), so I'm wary of too much.
 

Johnmac

Senior Member
Messages
756
Location
Cambodia
From an earlier email from Greg:

One thing new on the brazil nuts. On further investigation brazil nuts actually have selenomethionine, not selenocysteine, so they may not be the best source of selenium. I have stopped taking them now. Kind of annoying as they are put up as foods with selenium in them (which they do have) but it is not the right form.

:eek: (having just eaten my daily two brazil nuts...)

Does anyone have any more information on that?
 

alicec

Senior Member
Messages
1,572
Location
Australia
but it is not the right form.

That is the statement we would like more information about. As I discussed above, I can find no evidence for Greg's claims about this. All the literature I have seen indicates that selenomethionine, the form in brazil nuts (and plants in general) is a good source of selenium.
 
Messages
151
There are over 100 different forms of selenium in foods. The main seleno species in Brazil nuts is selenomethionine, and then two other ones which are not selenocysteine though it would contain selenocysteine plus all the other seleno species. Lamb kidneys have around 200mcg selenium per 100g, and half of it is in the form of selenocysteine from glutathione peroxide. Mustard seeds are another source of selenium. Tuna contains selenoneine which me make from the vitamin ergothioneine in mushrooms. High selenium yeast is 60-85% selenomethioneine, and the usual figure cited for selenocysteine content is 2-5% though it ranges from 0.5% up to 20%. Life extensions se methyl selenocysteine is NOT selenocysteine. It does not convert into selenocysteine in the body nor is it put into the 25 selenoproteins. We make selenocysteine from serine transfer RNA.
 

Carl

Senior Member
Messages
362
Location
United Kingdom
There are over 100 different forms of selenium in foods. The main seleno species in Brazil nuts is selenomethionine, and then two other ones which are not selenocysteine though it would contain selenocysteine plus all the other seleno species. Lamb kidneys have around 200mcg selenium per 100g, and half of it is in the form of selenocysteine from glutathione peroxide. Mustard seeds are another source of selenium. Tuna contains selenoneine which me make from the vitamin ergothioneine in mushrooms. High selenium yeast is 60-85% selenomethioneine, and the usual figure cited for selenocysteine content is 2-5% though it ranges from 0.5% up to 20%. Life extensions se methyl selenocysteine is NOT selenocysteine. It does not convert into selenocysteine in the body nor is it put into the 25 selenoproteins. We make selenocysteine from serine transfer RNA.
se-methylselenocysteine has been found in numerous studies to be the most effective form of selenium against cancer and for cancer prevention purposes. Therefore to suggest that it is inferior is incorrect IMO.

I supplement with both forms.

To suggest that CFS should be cautious about supplementation due to risk of taking too much is also an incorrect idea IMO due to CFS liver detox demands being so high and the requirement for glutathione being so high. This goes against all reasoning IMO. If CFS get the required co-nutrients then I doubt that selenium overdose from moderate supplementation will be a problem.

{edited by request *****************************************************************************************************}
 
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Messages
151
Se methyl selenocysteine compared to actual selenocysteine is not very good because it cant be made into selenoproteins. it is the 25 selenorproteins that have selenocysteine in them that exert their anti cancer action better than LE product. Me selenocysteine would be in food along with the other over 100 forms of selenium.

I never suggested being cautious with selenium. One study shows 3200mcg of selenomethionine a day for over 12 months is safe... People in Brazil eating brazil nuts that have a high content of selenium would be ingesting large amounts each day, and are healthy from it. Paradise nuts grown in certain places in South America contain 200 times more selenium than brazil nuts. There are cases of people ingesting what amounts to over one gram of selenium from them, and all that happens is they get sick for 1-2 days, then are fine. Selenium status is one of the main determiners of cancer risk...

If not wanting to eat brazil nuts, kidneys, or mustard seeds, or other foods high in selenium which can be looked up on nutritiondata, then high selenium yeast- not LE product- is the best supplement because it has the 100 natural forms of selenium in it not just a few.
 
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