Re: Is cryopreservation a solution?

Joao Pedro (
Sat, 13 Sep 1997 01:11:50 -0700


Even that one reaches death with few neurological destruction (which is
normally not the case), current techniques in cryopreservation damage
the cells severely. We are talking about bodies and not cell cultures.
To freeze a cell culture is easy but it must be done very gently not to
destroy the cells, to freeze a whole body is impossible without major
cell damage. Why?

It's simple, even if you're only frizzing the head, the temperatures
will always vary considerably between the cells at different positions.
More, the ideal rate at which you decrease the temperature surely varies
amongst different cell types. I read at least one good documented
experience (I'll try to find the authors) with the freezing of an
animal's brain in which they concluded that extensive tissue damaged was
observed. To give you another example, in the laboratory, only minimal
quantities of cells can be frizzed correctly, you can verify this at any
biology laboratory. You can argue that some destruction is caused in the
unfreezing process and that in the future this process will be perfect.
I don't know for sure exactly what are the percentages of cells damaged
in the freezing and unfreezing process but I expect that the cells
damaged in the unfreezing process to be less. If cells are not damaged
when the unfreezing process begins, they will not be destroyed then,
perhaps some cases of cells that are a bit damaged can be saved with
more advanced unfreezing processes but I'm moving to areas in which my
(and everyone, I suppose) knowledge is limited. I agree with Anders
Sandberg when he says that most of the damage is done in the freezing
process and not while we are frizzed.

Geoff Smith wrote:
> If I were to extrapolate current technological progress, I would say 100
> years is a very conservative estimate. The Prometheus Project's goal is
> much less.

That doesn't mean they will accomplish their goal. Besides, just because
they can unfreeze you, that doesn't mean they will. Remember, they will
only unfreeze you when aging is controlled and that can take a while.

Speaking about how long it will take for us to control aging, never
forget that even when we correct all the errors in our genome that
create aging now, we will have to worry about the errors that will cause
us diseases when we are 200, 300 or 1000 years old! Our knowledge will
have to advance faster than the millions of genetic errors that millions
of years of evolution have not corrected, it's a very difficult task
(that's why I'm 19 and already worrying about aging). For more see "Why
are We Allowed to Age?" in
(remember I asked this a couple of months ago?)

As a conclusion, I think that for old persons going to cryonics their
chances of immortality are minimal. If one is cryopreservated at an
early age with few brain damage then he might survive.

As for the identity issues, there are many interesting situations. Like
persons who endure terrible accidents or drug abuses. There is a case in
which a man had an iron through he's brain that completely changed his
personality although his intelligence was pretty much the same as
before. Is this the same person as before? I think not. Am I the same
person I was 10 years ago (neural changes have been huge)? No but I
changed, I blossomed into another person in a continuos process and that
is not the case in cryonics or accidents. Anyway, I'm not planning to
have irons going through my brain neither going to cryonics, I'll just
concentrate my efforts on the aging research.

Thank you all for your replies.

         Hasta la vista...

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