Selenium
By Dr. Alice R. Laule
Selenium is a powerful little micronutrient. One of its vital roles is in the
production of the anti-oxidant, glutathione reductasse. Watch for a future
article on the anti-oxidant cascade and the importance of glutathione. We do
not thrive without it, as you will see below. Additionally, selenium is
necessary for the conversion of the thyroid hormone T4 into its metabolically
active form, T3. When a patient seems to be clinically hypothyroid, sometimes
all that is needed is selenium. There are also numerous studies that indicate
selenium is useful in preventing some types of cancer, and in treating viral
illness. It is also found in dandruff shampoos. As a co-factor with vitamin E
it is anti-inflammatory and may even help prevent Alzheimer’s disease. Selenium
is incorporated into immune cells, and is involved in blood clotting.
Selenium in many of its forms is toxic, and its need in human nutrition was
only realized in the last part of the 20th century. Selenium deficiency is
common, particularly where the soils are depleted. In 1972, the USDA estimated
that 75% of Americans were selenium deficient. Only in a region around the
Dakotas is there sufficient selenium. Elsewhere, ranchers know that their
sheep, cattle and horses need to be fed supplemental selenium in mineral
blocks. We are just now beginning to realize that humans have the same need.
My friends, the biomedical researchers, were particularly interested in the
work of Dr. Harold Foster, a medical geographer. By studying the distribution
of disease as related to geography, Dr. Foster has discovered some fascinating
information. Most of the sub-Saharan countries have an incidence of AIDS as
high as 25%. Senegal, however, has only a 1-2% incidence. This coincides with
the fact that Senegal is the only country in the area that has adequate
selenium in the soil. This makes sense, in the light of other studies available
on AIDS and selenium showing that HIV (and other retroviruses) actually deplete
the selenium stores of the body, which then cannot produce glutathione. The
decline in selenium parallels the decline of the CD4 cells of the immune system,
allowing free rein for the virus to replicate more vigorously, promoting the
downward spiral and deadliness of AIDS.
You see, glutathione is a reverse transcriptase inhibitor — it reduces the
ability of the virus to reproduce itself. Glutathione
production requires selenium, and three amino acids, tryptophan, cysteine
and glutamine. By supplementing selenium and the three amino acids to
increase glutathione lives may be prolonged. Dr. Foster has written about a
double blind clinical study in Uganda using these supplements in which the
results are apparently very good.
Dr. Will Taylor has spent decades researching selenium as an inhibitor of
viral replication. Initially, he discovered the presence of selenium
receptors on the protein coat of viruses. For those who need a review of viral
anatomy, a virus is a pretty simple organism. It consists of a wad of genetic
material (DNA or RNA), enclosed in an outer protein coat, and equipped with a
syringe-like mechanism that allows the virus to inject itself into a host cell.
That’s it — just that simple. About a decade ago, Dr. Taylor spoke of an
unknown mechanism by which selenium acted as a “birth control pill” for the
virus so that in the presence of selenium, the viruses did not reproduce. In
reviewing his work recently, I discover that the mechanism is still not proven.
It appears to be a very complex gene-related mechanism, by which the virus
codes for production of a selenium containing protein, sort of like a viral
form of glutathione peroxidase. Since viral replication is triggered by the
presence of a lot of free radicals, perhaps the presence of its own glutathione
reduces free radicals and signals the virus to stay latent, fail to reproduce.
Whatever the exact mechanism, many viruses do this — the Ebola virus, Coxsackie
viruses, even possibly influenza and herpes.
In fact, Dr. Taylor reports an experiment in which the same strain of
Coxsackie virus was inoculated into two
groups of mice. One group of mice had lots of selenium and the other group had
been purposefully selenium depleted. The mice with plenty of selenium did not
get infected, but the selenium depleted ones did. The scary thing then is this:
when virus was recovered from the selenium depleted mice it had evidently
turned into a much worse virus. When it was transferred back to the mice that
didn’t get infected the first time around, they were not able to fight off this
new, more virulent virus, and they got sick.
If there are as many selenium depleted individuals in the world as some studies
indicate, this becomes fairly scary news. Fortunately, there are also plenty of
studies that indicate even in the face of severe viral epidemics,
treatment with selenium can be helpful. There is a viral disease called
Keshan’s disease which causes heart failure in young people in a region of
China. It has been successfully treated and prevented with selenium
supplementation. An outbreak of hemorrhagic fever in China in the late 1980’s
was treated and lives were saved with selenium supplementation. Selenium is
quickly becoming more than just a supplement of some nutritional value — it is
actually becoming a public health consideration.
Dr. Taylor states that selenium is probably also important in gene regulation,
in cell signaling (the way our cells talk to one another), in rheumatoid
disease, and other aspects of immune system regulation that we have only barely
glimpsed at this time.