I wanted to add some more to the interesting questions that you raise in
response to the book by Fossel.
The link between telomere shortening and organismal ageing, which forms
the basis of the book, and the proposed anti-ageing therapies is
unfortunately fragile at present. As such the book represents an
extremely premature popularisation of frontier science. In my opinion
such books, and the associated news coverage, are detrimental to medical
research as they foster unrealistic expectations among the general
public, expectations whose repeated dashing feeds back negatively on
science, and science funding. In my opinion this is an irresponsible
act.
First, let's take the underlying theory. As pointed out by another
respondent, telomere shortening has been shown to *correlate* with
*cellular* ageing. That means that it has not been shown to be causative
in the process of cellular senescence. It is clear that cells need to
maintain their chromosomes to be immortal. However, it remains
distinctly possible that other events make them immortal, and that they
switch on telomerase as a consequence of these other events. Of course,
the link between cellular senescence and organismal ageing is itself far
from clear. As you pointed out, some cells, such as neurons, are
non-dividing from early childhood until death, yet can function
adequately without telomerase.
Second, the therapies suggested are even more facile. If, as the book
demands, telomerase is really the master controller of cellular ageing,
and by inference critical in cellular transformation, then simply making
more of it all the cells of the human body is likely to have negative
consequences! Of course, of telomerase is irrelevant, then so are the
therapies.
My personal opinion is that this hypothesis is an illustration of the
old axiom that a little knowledge is a dangerous thing. It reminds me of
the anecdote popular in my field, of a now-Nobel laureate, who upon the
discovery of viral oncogenes (20 years ago), remarked to a colleague
something like: "now that we have the genes we'll have cancer wrapped up
in no time."
As the therapist of the anti-ageing clinic of the future might ask:
"Perhaps you'd like a little melatonin with your telomere therapy, sir?
And while you wait for it to take effect, perhaps you'd care to browse
through this catalogue of famous bridges we have on special offer this
week?"
