Selenium - Which Form?

[Remy]

I've always heard that L-selenomethionine was the best form of selenium to take but recently I've been hearing more about selenium-methyl L-selenocysteine.

It looks like they may work slightly differently in the body and I'm curious if anyone has any experience with one over another? Should we take both?

http://www.lifeextension.com/magazine/2012/ss/selenium-protect-against-cancer/page-01

Laboratory studies reveal several mechanisms of action unique to this form of selenium. Perhaps most intriguingly, selenium-methyl L-selenocysteinesupplements restore proteins associated with normal circadian (24-hour) rhythms.58 Disruptions in circadian rhythms are associated with development of several cancer types, most notably breast cancers. Restoring those important regulatory proteins with selenium-methyl L-selenocysteine normalizes levels of melatonin and estrogen receptors related to the aggressiveness of breast cancers.25

http://www.advance-health.com/selenium.html

Because cells cannot distinguish selenomethionine from the essential amino acid methionine, some selenomethionine becames incorporated into general body proteins, increasing tissue selenium levels.

 

[Who Me?]

I have always been told to take the non-yeast one. I took 200 mcg and never noticed anything.

 

[Cort]

I've always heard that L-selenomethionine was the best form of selenium to take but recently I've been hearing more about selenium-methyl L-selenocysteine.

It looks like they may work slightly differently in the body and I'm curious if anyone has any experience with one over another? Should we take both?

http://www.lifeextension.com/magazine/2012/ss/selenium-protect-against-cancer/page-01


http://www.advance-health.com/selenium.html

Any particular reason that you're taking it? If its for low thyroid Chris Kresser has a cautionary note:

http://chriskresser.com/important-update-on-selenium-supplementation/

“These preliminary studies show the positive effects of selenium supplementation on inflammatory activity in autoimmune thyroid conditions, but the long term effects of supplementation on thyroid health are still unknown. And we know that selenium is an essential component of the enzymes that convert T4 to T3, but whether supplementation will increase serum T3 levels is unclear.​

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While it seems that selenium supplementation would be an obvious solution to poor thyroid function, long term consumption of high doses of selenium can lead to complications such as gastrointestinal upsets, hair loss, white blotchy nails, garlic breath odor, fatigue, irritability, and mild nerve damage. (1) Additionally, supplementing selenium in the context of low iodine status may actually aggravate hypothyroidism. Mario Renato Iwakura discusses this particular topic extensively on Paul Jaminet’s Perfect Health Diet blog.​

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For now, the best option for most people may be to include selenium-rich foods in the context of a healthy Paleo diet.”​

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He notes that if you have low tissue selenium levels then selenium supplementation can probably help but if you have normal tissue levels it could be a problem​

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So what are we to make of this? A growing body of research suggests that the effects of micronutrient supplementation are dependent upon the status of that nutrient in the target population. (6) If baseline levels of a particular nutrient are low, supplementation may lead to improved outcomes. But if baseline levels are normal or high, supplementation may cause harm—as it appears to have done in this study. This shouldn’t be too much of a surprise. Most nutrients have a “U-shaped curve”, which means that both too little and too much can cause problems.

On the other hand, several studies indicate that supplementing with selenium has several benefits for people with autoimmune thyroid disease, including reduced inflammation and damage to thyroid tissue. At least one study found that selenium supplementation produced these benefits even when selenium levels were normal at baseline. (7) Since both Hashimoto’s and Graves’ disease are associated with increased morbidity and mortality, an intervention that reduces the autoimmune/inflammatory burden in these conditions might be expected reduce morbidity and mortality.

There’s little doubt that maintaining adequate selenium levels is important to immune and thyroid function. But given the potential long-term risk of supplementation, I think the best option for most people is to meet their need for selenium by eating selenium-rich foods. Great sources include: brazil nuts, crimini mushrooms, cod, shrimp, tuna, halibut, salmon, scallops, chicken, eggs, shiitake mushrooms, lamb, and turkey. Brazil nuts are a particularly rich source; just 2–3 a day will provide roughly 200 mcg of selenium, which is the amount used in many of the autoimmune thyroid studies.

Finally, while this study was focused on prostate cancer risk in men over 55, it’s probably prudent to assume that long-term selenium supplementation in both younger men and women of any age may also have undesirable effects.
I

 

[Remy]

Any particular reason that you're taking it?

Yes, I tested low on the Spectracell analysis...but mostly for it's beneficial effects on glutathione.

http://www.immunehealthscience.com/benefits-of-selenium.html

Glutathione peroxidases, also known as selenoproteins, are a family of antioxidant enzymes that speed up the reaction between glutathione and free radicals, particularly toxic hydrogen peroxide, which selenium-containing glutathione peroxidases help transform to harmless water. These enzymes act both inside and outside the cells maximizing antioxidant protection.

In cases of selenium deficiency and with the resulting impaired function of glutathione peroxidases destructive hydrogen peroxide breaks down into even more dangerous hydroxyl radical which damages cell membranes and cell DNA eventually leading to serious disease. Selenium is directly involved in preservation of cell membrane integrity and DNA integrity.
The benefits of selenium are the result of the activity of glutathione in our bodies. Research done with selenium proves this connection – low selenium levels are noted in the health conditions that show low glutathione levels.

The statement about iodine is interesting, given that selenium is one of the single best ways I know of to reduce Hashi's antibodies. It seems like iodine is coming back into favor again.

Selenium suffers from the same problems as almost all supplements...the Goldilocks effect. Recent studies are a bit concerning though regarding what constitutes a "safe" dose. I've requested the following article:

J Environ Sci Health C Environ Carcinog Ecotoxicol Rev. 2015;33(3):328-68. doi: 10.1080/10590501.2015.1055163.
Selenium and Human Health: Witnessing a Copernican Revolution?

Jablonska E1, Vinceti M.
Author information


Abstract

In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.

 

[Remy]

So here are my thoughts after reading a lot more about selenium in the past few days...

So it looks like everyone was solidly on this selenium/Vit E bandwagon...enough so that they did a big study called the SELECT trial that started in 2001 (a year after these papers were published). Unfortunately it was a failure at preventing cancer. And may have even increased the risk for cancer and diabetes.

Here is a summary of the SELECT trial (there are also some criticisms of the trial listed at this site):

SELECT is the second large-scale study of chemoprevention for prostate cancer. Chemoprevention or chemoprophylaxis refers to the administration of a medication to prevent disease. The SELECT trial aimed to determine whether dietary supplementation with selenium and/or vitamin E could reduce the risk of prostate cancer among healthy men. It is a randomized, prospective, double-blind study with a 2×2 factorial design, which means that the volunteering men received either one of the supplements, both supplements or no supplements (but placebo instead), without knowing which treatment they would receive.
The trial volunteers were randomly assigned to one the following treatments:

• 200 µg of selenium and 400 IU of vitamin E per day. (both supplements)
• 200 µg of selenium per day and placebo
• 400 IU of vitamin E per day and placebo
• two different placebo’s (neither supplement)
• (µg = micrograms, IU = International Units)

Enrollment for the trial began in 2001 and ended in 2004. Supplements were to be taken for a minimum of 7 years and a maximum of 12 years. Therefore the final results were anticipated in 2013. However, but due to the negative preliminary results, SELECT participants still in the trial are now being told to stop taking the pills. The participants will continue to have their health monitored by study staff for about three more years, continue to respond to the study questionnaires, and will provide a blood sample at their five-year anniversary of joining the trial, to ensure their health and to allow a complete analysis of the study. (see SELECT Q & A).

So based on this trial, another paper from 2015 went back to summarize the selenium studies and came to some disturbing conclusions...namely that selenium may be causing the very oxidative stress that it is purported to relieve.

J Environ Sci Health C Environ Carcinog Ecotoxicol Rev. 2015;33(3):328-68. doi: 10.1080/10590501.2015.1055163.
Selenium and Human Health: Witnessing a Copernican Revolution?
Jablonska E1, Vinceti M.
Author information
Abstract
In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.

Even more disturbing was this part...

"Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations."

It's long been assumed that selenium is safe under about 400 ug/day but it's looking like that may not be true.

Until we have some more research, I think I'd be wary of selenium at all, unless you've tested low for it specifically. And I'd definitely take mixed tocopherols if taking Vit E.

 

[Empty]

I would go with brazil nuts. 3 Provides the rda.

 

[Issie]

I would go with brazil nuts. 3 Provides the rda.

I say Brazil nuts too. I was told to only have 1 nut a day. Reason is not all will have the same mg in them. Too many Brazil nuts can be hazardous to your health.

Issie