Another caution on dietary selenium

Mark suggests the following article as a caution on
dietary selenium.

Quoted message said:

nutrition.org1736Open ↗

As I read it, however, it seems to be saying selenium helps
lower homocysteine, which is a good thing, no?

--
John de Hoog dehoog.orgdehoog.orgOpen ↗

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

nutrition.org1736Open ↗

Mark, You probably read the title only (which is somewhat
misleading;-/ "Serum Selenium Is Associated with Plasma
Homocysteine Concentrations in Elderly Humans" - it's an
*inverse* association. It should have been either
"(low)Serum Selenium Is Associated with Plasma Homocysteine
Concentrations in Elderly Humans" or "Serum Selenium Is
(inversly) Associated with Plasma Homocysteine
Concentrations in Elderly Humans".

As a few have kindly mentioned I didn't note the inverse
correlation statement of the correlation when reading in
haste, thanks for doing so.

Hi there John,

That's my reading of it.

-Chad

"John de Hoog" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Mark suggests the following article as a caution on
dietary selenium.

Quoted message said:

nutrition.org1736Open ↗

As I read it, however, it seems to be saying selenium
helps lower homocysteine, which is a good thing, no?

--
John de Hoog dehoog.orgdehoog.orgOpen ↗

"John de Hoog" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Mark suggests the following article as a caution on
dietary selenium.

Quoted message said:

nutrition.org1736Open ↗

As I read it, however, it seems to be saying selenium
helps lower homocysteine, which is a good thing, no?

--
John de Hoog dehoog.orgdehoog.orgOpen ↗

Yes, a good thing, and it predicted serum homocysteine
better than folate status. I think he misread the article.

Lar

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

As a few have kindly mentioned I didn't note the inverse
correlation statement of the correlation when reading in
haste, thanks for doing so.

Now when you say "another" caution are you saying there
are "studies" that show selenium is bad!? and some that
show it is good!!?? Im so confused! Or is this another one
of your self correcting events of science. Or maybe there
is just no such thing as truth or reality and its all
relative in some way.

On 30 Jun 2004 23:01:11 -0700, [email hidden] (Wolfbrother)

Quoted message said:

[email hidden] wrote in message news:<[email hidden]-
net.com>...

Quoted message said:

As a few have kindly mentioned I didn't note the inverse
correlation statement of the correlation when reading in
haste, thanks for doing so.

Now when you say "another" caution are you saying there are
"studies" that show selenium is bad!? and some that show it
is good!!?? Im so confused! Or is this another one of your
self correcting events of science. Or maybe there is just
no such thing as truth or reality and its all relative in
some way.

Ah--actually, I think that the issue is dose. Selenium IS
extremely toxic. So you don't want to overdo, clearly.
Probably 600-800 micrograms per day (depending on the form?)
is probably a maximum.

By contrast, low selenium levels have been implicated in a
variety of diseases from HIV to Keshan's disease (caused by
a Coxsackie virus). One of the most intriguing studies I
ever saw was one where when the virus was passaged through
selenium-deficient rabbits, they got sick.

OK, that's not so interesting--but then what they did next
was. They EXCISED the pathogenic bits of the viral genome.
So when they infected rabbits with the virus who had had
enough selenium, no trouble.

But here's the frightening part. When they passaged
the virus through selenium-deficient animals, the
virus reacquired the pathogenic elements and they
developed disease!!

The most critical aspect of this is the "evidence of
principle" that nutritional status not only increases
susceptibility to disease--but may ALSO affect the
pathogenicity of infectious agents!! All the MORE reason to
assure that people aren't starving in this world, in my view
(as if the humanitarian reasons weren't enough).

In addition, the role of selenium deficiency in HIV disease
is quite important and repletion is helpful in slowing
disease progression--best provided through a multivitamin of
significant potency. It is interesting to note that the HIV
genome carries a frameshift gene for glutathione peroxidase
that it may use to protect infected cells from destruction.

George M. Carter

***
Levander OA, Beck MA. Selenium and viral virulence. Br Med
Bull. 1999;55(3):528-533.

Nutrient Requirements and Functions Laboratory, Beltsville
Human Nutrition Research Center, US Department of
Agriculture, Maryland 20705-2350, USA.

A mouse model of coxsackievirus-induced myocarditis is being
used to investigate nutritional determinants of viral
virulence. This approach was suggested by research carried
out in China which showed that mice fed diets composed of
low selenium ingredients from a Keshan disease area suffered
more extensive heart damage when infected with a coxsackie
B4 virus than infected mice fed the same diet but
supplemented with selenium by esophageal intubation.
Selenium deficiency in our mice increased the virulence of
an already virulent strain of coxsackievirus B3 (CVB3/20)
and also allowed conversion of a non-virulent strain
(CVB3/0) to virulence. Such conversion of CVB3/0 was
accompanied by a change in the viral genome to more closely
match that of the virulent virus, CVB3/20. As far as the
authors are aware, this is the first report of host
nutrition influencing the genetic make-up of an invading
pathogen. Nutritionists may need to consider this mechanism
of increased viral virulence in order to gain a better
understanding of diet/infection relationships.