On 11/29/2008 08:54 AM, Steve Floyd Jr wrote:

<snipped information relating to source of this dialog>
> Hi Paul,
>
> I am working on my literature review for my organic chemistry
> course, which is due this week. This literature review is concerned
> with the possible negative health-consequences of high iron status.
> It's coming along fairly well, but there's one point I would like to
> make in this review that I don't yet have sources for. I remember
> reading an article recently (I think on Morelife Yahoo) where you
> caution Olafur about blood donations. You mention that blood
> donations, while effective at lowering iron stores, may have
> unforeseen negative effects, such as depleting limited immune cells,
> stem cells, and others. I was wondering if you had any references for
> those assertions, as I would like to discuss these negative
> consequences in the section of the paper where I discuss phlebotomy
> as a method of reducing iron stores. If not, I will search for them
> on my own, as I think it is prudent to give an accurate benefit vs.
> risk evaluation in a paper such as this. Even pointing me to a
> certain journal or article on sci.life-extension or other such group
> would be very helpful. I spent a little time searching for several
> items in Morelife Yahoo and sci.life-extension and did not find what
> I am looking for.
>
> ---
> Steve Floyd
>

[The messages Steve is referring to are in the thread that began in April 2005
and started with http://health.groups.yahoo.com/group/morelife/message/931
**Kitty]

I think that you have misunderstood my argument. The fact that donations
of whole blood temporarily decrease *all* blood components is pure logic
and therefore needs no references. The results of blood donations that
do need consideration are:

1) How fast will the optimal level of blood components (which, except
for iron, you presumably had before the donation) be restored? Now most
doctors and the blood donation clinics will say even this does not
matter much because after all, the donation is only 250 ml which is only
about 5% of the total amount of blood in your body (about 5 liters for a
normal adult human). However, even though I agree with this somewhat,
nevertheless the body has lost blood components that it had produced
according to its determination of its most optimal state. I do not know
how long the restoration of each blood component will take, but I have
no great concern about any negative effects from such a small depletion
over this time period, since I know that the body can quickly upregulate
its production of any one of these components (particularly white blood
cells) if it should determine the need to do so. However, this is not
true for memory white blood cells that have been trained by encounter
with previous pathogens, including through vaccinations, to quickly
initiate an immune response and thus prevent any new appearance of that
same pathogen from causing any major harm. These appear to remain in the
blood system for life and only slowly decrease with time, perhaps even
because of normal blood loss - I don't think that anyone really knows
the full reasons for the rate of decrease, which definitely varies
between individuals. There may even be other, perhaps unknown, blood
components that one has acquired over time and with maturity which will
be depleted by blood donations and only very slowly regained, if ever.
Scientists are far from knowing and understanding all aspects of the
human body, not even the blood, which is a highly complex mixture.

2) Any loss of essential body cells will require their progenitor cells
to divide in order to replace those lost cells. While this is not going
to be a problem acutely (if occurring only a few times or very
infrequently), if done chronically (as some people are advising), it
will, over time, deplete the division potential of the cells that
produce the blood cellular components, and if done sufficiently often
the doubling time potential of those cells (the Hayflick limit) may be
reached and become a limiting factor to lifespan. (There is already good
evidence that the Hayflick limit plays a part in the exhaustion of white
cell division that occurs with AIDS.) In addition, the cells that
produce non-cellular blood components will constantly be operating at a
higher rate than they normally do in the body, which logically also may
have negative effects on their healthy lifespan. Now for a normal
healthy person a reasonable number of blood donations may not have a
significant effect with respect to the doubling potential that is
required for a normal lifespan - see http://pmid.us/12869115 - (one has
to search very hard to find any mortal pathology that is potentially
caused by exhaustion of the cell doubling ability - AIDS is the only
possibility that I know of), for a life extensionist, any unnecessary
reduction of doubling ability of any stem cells is negative to continued
life, as long as it can possibly be avoided. However, with respect to
the trained and specialized cells mentioned above, if many blood
donations are given this must necessarily result in a cumulative loss
and should weaken your immune response to previous pathogens that your
body has detected and conquered. (And I know of no study, such as the
above linked for telomere length, which has tested the effect of
repeat blood donations on immune cell depletion.)

These are the major reasons why I disagree with some people who are on
sci.life-extension (and some doctors elsewhere) advising others that it
is health and life extension promoting to donate blood every 2-3 months
for the rest of their lives, at least into very old age and dysfunction.

In summary, it is not logical to eliminate a number of blood components
that a healthy body has determined are needed for continued optimal
health, merely because one of those components is deemed to be negative
for long-term health and the mechanisms of the body have not been able
to either determine that or do something about it. Rather if one finds
that one has very high iron stores, then yes, it is a good idea to
donate blood every 3 months for a while until iron stores are at a more
healthy lower range, even though this is going to be slightly harmful
(for the reasons given above). This is necessary and valuable *only*
because no other reasonable and effective method of ridding one's body
of iron only (very strongly sequestered by the body for evolutionary
reasons) is known at this time. However at the same time, it is vital to
alter one's diet to reduce iron accumulation in the body. This can
easily be done by reducing consumption of red meat, eggs, etc (heme
iron) and increasing consumption of fibers that prevent the absorption
of iron from the GI tract.

--Paul