Selenium has been in the news recently as a cure or preventative for cancer. A mineral found in the soil, selenium is one of the essential elements. There have been many studies done on the relationship between selenium and the treatment cancer, diabetes, thyroid problems, cognitive function and many other ailments.
What is Selenium?
Selenium is a nonmetallic trace element rarely found in its pure state in nature. It is produced as a mining by-product of sulfite ores, such as copper, and has certain industrial uses. For us, however, a tiny dose of selenium is essential for good health.
Selenium and Glutathione
Probably the most important reason for ensuring that we have enough selenium is that our bodies need it for the production of glutathione peroxidase (GSH-Px), an antioxidant that aids every cell in our bodies to fight illness and thus maintain health.
During an illness, you need more glutathione than normal as the body uses it to remove toxins from the body. Naturally, the more glutathione we use, the less we have in supply. When glutathione levels have been depleted, free radicals accumulate and these can damage cell membranes. Depleted glutathione levels therefore need to be renewed.
Maintaining Glutathione Levels
Selenium is important for the production of glutathione in our body. Studies have shown low levels of both selenium and glutathione when people are ill.
It would seem logical to think that taking up to 200 mcg/day selenium when sick would be a good idea, but we could not find research to confirm this.
If you took selenium when you were sick, please let us know the details on how it worked for you.
Diet. When healthy, people usually get all the selenium that is needed from their food. However, people tend not to eat a balanced diet when sick, leading to the risk of a diet not rich in essential elements such as selenium.
Exercise is also a good way to help restore glutathione levels, but this is also something sick people cannot easily do.
Bioactive whey protein, made from denatured proteins and produced from raw milk (not containing hormones, pesticides or antibiotics), will help to maintain glutathione levels.
Obtaining Selenium from a Healthy Diet
Plants draw selenium from the soil, but the amount of selenium in the soil varies. In most parts of the world, there is sufficient selenium in the soil. However, in one region of China, selenium deficiency in the soil was eventually tied to people suffering from multiple ailments.
- Selenium can be obtained from a wide variety of foods. However, selenium from grain-based foods is dependent upon selenium levels in the soil. Most vegetables and fruits do not contain much selenium.
- Tuna is very high in selenium (4 oz. = 123 mcg), as is other seafood such as shrimp, sardines, oysters and salmon.
- Brazil Nuts contain 544 mcg per ounce; selenium is also found in black walnuts, cashews and macadamia nuts.
- Whole-wheat bread has 11 mcg per slice. It is also found in other whole-wheat products, such as English muffins, pita bread, etc.
- Meat contains selenium. On average, a 3 oz. serving of lean meat or poultry will supply 25-35 mcg of selenium.
- Sunflower seeds supply 78 mcg of selenium per 100 grams of seeds.
Benefits of Selenium:
- A sufficient supply of selenium is essential for the production of the critical antioxidant enzyme glutathione. This may be the most important benefit of selenium. It appears that benefits claimed for selenium could be the result of selenium providing for adequate levels of glutathione.
- Selenium helps to support the immune system.
- It is needed to regulate thyroid function.
- It assists in preventing cataracts.
- Antioxidant properties of selenium may help to prevent damage to cells from free radicals. It may also work in the prevention of heart disease.
- Selenium may help to reduce the risk of developing prostate, skin and some other cancers. See SELECT trial information below.
- Inflammation associated with rheumatoid arthritis may be lessened by selenium.
- Selenium is said to reduce the risk of sunburn.
The FDA and Selenium
In 2003, the FDA issued a qualified approval for selenium as a cancer preventative, with the caveat that the sale of the supplement was accompanied by a warning stating that while selenium could reduce the risks of some cancers, it might carry a carcinogenic effect for other cancers.
At the end of a rather long opinion, the bottom line is that selenium supplements can be sold, but the FDA won’t allow the manufacturers to say unequivocally that the supplements will be useful in preventing cancer. In our view, the research for this stance is limited.
Selenium and Cancer
A few years ago, there was a lot of excitement about the possibility of selenium preventing cancer. Many studies tried to determine whether selenium could help to prevent cancer, either taken alone or with vitamin E. But the research results were not found to be conclusive.
The SELECT Trial for Prostate Cancer
The Selenium and Vitamin E Cancer Prevention Trial (SELECT) (SELECT) divided 35,000 men, considered to be at moderate risk of prostate cancer, into 4 groups in the U.S., Canada and Puerto Rico. This study began in 2001. Their conclusions were as follows:
Group 1: Received only synthetic Vitamin E (400 IU/360 mg/day).
Conclusion: The synthetic Vitamin E was stopped in 2008. A follow-up in 2011 revealed that more men developed prostate cancer than in the placebo group. Never take synthetic Vitamin E.
Group 2: Received only selenium (200 mcg/day as L-selenomethionine).
Conclusion: This did not work as expected. The researchers speculated that the problem was the form of selenium given to the men. They received selenomethionine, which had a synthetic component. The researchers felt that selenium yeast, used in previous trials at a dosage of 200 mcg/day, would have been a better choice, but only for men who began the trial at a low selenium level.
Group 3: Received both Vitamin E and selenium.
Conclusion: Again, the researchers felt that the form and dosage had been wrong. Selenium yeast had previously been shown to have a protective effect in past trials. They felt that the type and dosage were wrong for the vitamin E. Natural vitamin E at a dosage of 50 IU (compared to the 400 IU used in SELECT) was proven beneficial in other trials.
Group 4: Received only a placebo
FORM AND DOSE MATTER A LOT!
IMPORTANT: Before starting to take selenium, it’s important to know your selenium level. Selenium had a protective effect for men who had a low selenium level. However, men who started taking selenium when they already had a high level of selenium developed an increased risk of developing aggressive prostate cancer.
A blood test for selenium without insurance at a walk-in lab costs about $150.00.
The SELECT trials were studying prostate cancer. Whether taking natural Vitamin E and selenium yeast at the recommended doses would be helpful against other cancers is unknown.
Selenium and Alzheimer’s
Research has been inconclusive as to whether selenium supplements could prevent Alzheimer’s. A French study of over 4,000 people aged 45-60 found that those who took a supplement containing 100 mcg selenium, ascorbic acid, vitamin E, beta-carotene and zinc for 8 years had improved memory and speech compared to those taking a placebo. However, the study could not say whether or not selenium by itself would have had the same effect.of over 4,000 people aged 45-60 found that those who took a supplement for 8 years containing 100 mcg selenium, ascorbic acid, vitamin E, beta-carotene and zinc had improved memory and speech compared to those taking a placebo. However, they could not say whether or not selenium by itself would have the same effect.
Selenium and Diabetes
Some studies show a possible link between as little as 200 mcg selenium and an increased risk of Type 2 Diabetes.
Recommended Selenium Doses
- Children: 20 – 40 mcg (micrograms)/day
- Adults: 55 mcg/day
- Pregnant women: 60 mcg/day
- Breastfeeding women: 70 mcg/day
How Much Selenium is Too Much?
According to the U.S. Institute of Medicine, over 400 mcg of selenium a day is considered an overdose. Over 800 mcg would be a toxic level, leading to selenosis. This can result in hair loss, gastrointestinal upset, garlicky breath, discolored nails, irritability, fatigue and possibly mild nerve damage.
It needs to be pointed out that selenium can be ingested during the day from multiple sources, including food, selenium supplements and multivitamins or other supplements containing selenium. Taking 2 – 200 mcg capsules would result in a daily dose of over 400 mcg for most people.
Selenium is essential, especially to maintain necessary glutathione levels, but adequate amounts can normally be received from food. If taking a supplement, be careful as to the form of selenium taken and the dosage.
Please let us know if you take selenium, the dosage you take, and how it is working for you!