Our contributing medical editor, Andrew L. Rubman, ND, has been vocal about his enthusiasm for the trace element selenium for years — including defending this important antioxidant mineral against research that seemed (wrongly, in his view) to link it to diabetes. Along with others, he was unsurprised by new research showing it to be valuable in the fight against assorted cancers including lung, colon and prostate. Beyond cancer, studies show that selenium also appears to stimulate the immune response in general and contributes to the health of the thyroid gland.
There’s still lots to learn about selenium, but we do know it’s complicated. To find out more about what these research findings mean to you, I called selenium expert Julian Spallholz, PhD, professor in the department of food and nutrition at Texas Technology University (Lubbock). He affirmed that selenium is vitally important as a cofactor both for antioxidant enzymes and in 25 vital human proteins that cannot function without it. Though the Recommended Dietary Allowance (RDA) for adults is 55 mcg/day, whether or not an individual gets enough from dietary sources depends on how much selenium normally exists in the soil in your region and/or where your food (plant- and animal-based) originates. Parts of the US and much of Europe are known to have low levels of selenium, while other areas — notably the Midwest and Western states, including Colorado, Texas, Nebraska, Utah, Montana and Northern Arizona — have more. (Note: A selenium country-wide map can be found at http://tin.er.usgs.gov/geochem/doc/averages/se/usa.html.)
While symptoms of selenium deficiency are up for debate (possibly including muscle weakness, and immune, digestive and respiratory disorders) what’s known for sure is that severe deficiency causes several terrible diseases. In particular, in regions of Asia, where the levels of dietary selenium are as low as 10 mcg a day or less, people may be affected by Keshan disease, which harms the heart, and Kashin-Beck disease, which attacks the joints.
Advice on supplementation is far from simple — it’s not as easy as taking a daily pill and being done with it. Taking too much can be dangerous, though Dr. Spallholz said that the 200 mcg/day used in studies is considered well within the safe range. Even in the same region, different people will have different requirements. Dr. Rubman told me that while he often prescribes selenium to his patients for a variety of symptoms, he always adjusts dosage and duration for each patient individually.
SELENIUM BENEFITS
A believer in the immune-boosting qualities of selenium, Dr. Rubman has used it to fight skin lesions in a teenage boy caused by the resistant bacterium MRSA. Suspecting a selenium deficiency, in part because of his tendency toward dry skin and dandruff (possible indications of low levels), Dr. Rubman prescribed a liquid form (selenious acid) to be taken orally, along with other supplements to maximize his immune functions, along with a topical form of selenium. Symptoms improved in days and within a few months the lesions were gone.
Even the toxicity of selenium has a useful aspect — Dr. Spallholz told me that he’s been involved in development of several drugs using it as an experimental coating to prevent bacteria from growing on orthodontic braces and bands. It’s easy to see it might also have the potential to protect hospital catheters from bacteria, including antibiotic-resistant ones, as well.
Going forward, I believe that we will be hearing much more about selenium as a cancer-fighting and immune-boosting nutrient. In the meantime, both Dr. Spallholz and Dr. Rubman advise taking a high-quality multivitamin that contains selenium. Dietary selenium is available through grains grown in selenium-rich soil and also from Brazil nuts, as well as from seafood and animal products, including eggs and dairy. That advice, at least, is easy enough to understand and the health benefits that may follow make it well worth doing, in my view.
