Selenium, an essential trace mineral, is now recognized as indispensable for maintaining great health. Less well known, perhaps, are the frightening implications of a selenium deficiency. Now, groundbreaking research has demonstrated that shortages of this mineral may play a role in the emergence of new and dangerous viral strains – and could even trigger epidemics.
With well over 100,000 people hospitalized yearly in the United States for influenza viruses – and 20,000 plus losing their lives due to its complications – it has never been more important to understand and address the threat presented by poor selenium status.
Selenium protects against oxidative damage
Selenium exists naturally in soil – and is also found in the bodies of animals and humans, where it performs many important biochemical functions. These include helping to regulate metabolism, managing normal growth, orchestrating reproduction, neutralizing free radicals and defending against infections.
Selenium is a component of glutathione peroxidase, the body’s ‘master’ antioxidant, and is incorporated into at least 25 different proteins. Selenium neutralizes free radicals by rendering them harmlessly within our bodily fluid.
As a constituent of glutathione, selenium helps protect cardiovascular health by combating the oxidation of fats and reducing the “stickiness” of blood platelets. It also helps to neutralize toxins.
Selenium deficiencies are more likely to occur in parts of the world where the soil is naturally low in this mineral. However, recent research suggests that the consequences of poor selenium status may have the capacity to impact other populations as well.
Alarming study shows link between selenium and increased virulence of pathogens
In a study conducted at the University of North Carolina at Chapel Hill and published in FASEB – the journal of the Federation of American Societies for Experimental Biology – researchers found that inadequate intake of selenium increased damage caused by the influenza virus.
Even more troublingly, they discovered that the influenza virus mutated when it passed through selenium-deficient mice. Not only did it emerge more virulent than before, but it was then able to infect mice with optimal selenium status.
To conduct the study, the researchers divided the mice into two groups and fed them either a normal diet or a selenium-deficient diet. Both groups were then exposed to Influenza A Bangkok, a mild strain of human flu virus.
The mice with low selenium levels had lung inflammation that was significantly more pronounced and longer-lasting. The difference was so profound that the researchers likened the disparity to the difference between mild pneumonia and severe pneumonia, which can be life-threatening.
The team also found that the viruses from the selenium-deficient mice had mutations in the gene for the M1 matrix protein, which is associated with viral replication. Once the virus had mutated, even well-nourished mice were susceptible to the new, more virulent strain.
The findings, which suggested that nutritional deficiencies can promote epidemics by contributing to the emergence of new viral strains, were deemed “disturbing” by the team.
Alert: some researchers believe that the emergence of Ebola virus – as well as new strains of influenza and the common cold – could stem from viral changes brought about by interactions with selenium-deficient hosts from areas of low soil selenium. In other words, people from low-selenium areas could be acting as unwitting “incubators” for more virulent pathogens.
Selenium deficiency allows a benign virus to mutate and damage the heart
In a related study, researchers found that selenium deficiency can cause coxsackie B3 – a normally mild virus – to mutate into a microbe capable of attacking heart muscle. The resultant heart inflammation is known as Keshan disease – a condition which affects the population in parts of rural China where the soil is deficient in selenium.
In a study published in The Journal of Nutrition, researchers fed mice a selenium-deficient diet for four weeks, then inoculated them with a strain of coxsackie B3 that would not normally cause cardiac inflammation.
The deficient mice not only had five times less beneficial glutathione activity than the mice with adequate selenium, but they developed heart damage. The virus was then inoculated back into the well-nourished mice that had adequate amounts of selenium. And the results were troubling – those mice, as well, developed heart damage and myocarditis.
Selenium supplementation can help arrest the progression of serious diseases
While deficiencies in selenium can make viruses more dangerous, research is demonstrating that supplementary selenium can have beneficial results.
For example, supplementation with selenium drastically reduces the incidence of hepatitis B in both animals and humans. In those already infected with hepatitis B, selenium supplementation can prevent the progression to liver cancer.
Selenium can also help prevent the progression of HIV infection to full-blown AIDS. A placebo-controlled double-blind study showed that HIV-positive men and women receiving selenium supplementation were admitted to the hospital less often than those who received a placebo.
Selenium supplementation may even benefit those who aren’t deficient
Research shows that supplementation enhances the immune response – even in those with optimal levels. In a study published in Biological Trace Element Research, researchers found that 200 mcg a day of selenium increased the activity of natural killer cells by 82 percent.
Natural health experts say that 55 micrograms of selenium a day – the amount recommended by the Institutes of Medicine – may be insufficient when it comes to immune system enhancement and cancer prevention.
If you think selenium supplementation is for you, discuss the matter first with a trusted, healthcare provider, who can advise a dosage.
Good dietary sources of selenium include Brazil nuts, eggs, liver and sunflower seeds.
Note: excess ingestion of selenium can cause neurological problems. Experts advise staying under the upper tolerable intake limit of 400 mcg per day. Because an ounce of Brazil nuts weighs in at a whopping 544 mcg of selenium, it is best to eat them only sparingly – especially if you already taking supplements with selenium.
Sources for this article include: