X-Message-Number: 27919
From: "Hare, Tim R" <>
Subject: RE: [CN] CR and brain aging
Date: Sun, 7 May 2006 14:19:03 -0400

Dear Doug, 

You clearly provide an essential service by infusing the CN listsrv with a
variety of publicly available abstracts to stimulate discussion, and it is
(arguably) the outcome of this down-stream consideration (with increasingly
detailed analysis that involves access to the entire citation, via selected
quotation) that best serves us all, wrt to our odds of living long...and
being preserved on demise with the utmost integrity.

From time to time, however, one is inclined to reference one's own opinion,
and emphasize the strength of one's emotional conviction.  This is expedient
[requires less citation, unless one is highly published... :) ], but is more
likely to be (and should be) challenged than is an (apparently) impartial
consideration of the weight of all available published data, with in-line
citation of one's list of reference including details quoted from beyond
that of the abstract. 

In an attempt to inform and empower, I've succeeded in setting aside a bit
of time this weekend (though I expect Rudi Hoffman will cringe and require
explanation....don't worry Rudi, those docs will be in the mail shortly) to
assemble a sampling of the primary literature on this important topic.  I'll
try and get this posted soon.  I'll try and be complete and detailed, and
impartial.  We'll all benefit.  

No one on this list will want to leave unexplored the critical caveat you
last presented; that of CR being potentially ineffective at preserving
critical structure and function, associated with cognition, during aging.
As well, you note below that "For the record I doubt that mild CR in humans
would reduce brain function at all, but severe CR might be another matter."
This needs to be examined, as well: if there is any chance that "mild CR"
will reduce brain function, this likely impacts many. If any form ("severe"
or no) of CR is deleterious to the brain, it deserves to be routed out and
made public, for all to benefit.  

More to the point, though, and as noted in prior emails, none of us will
want to avoid consideration of CR (or any other approach) in brain (or
overall) aging, because it arms us with information that enables the
recognition and development of future therapeutic approaches -- or, per your
admonitions, allows us to avoid those that simply don't work, or may even
hasten our demise.  That is, one need not advocate, nor practice, CR, to
benefit from the study of it's effect, be they positive or negative.

Best, T-

"Posterity: you will never know how much it has cost my generation to
preserve your freedom. I hope you will make good use of it." - John Quincy
Adams      

-----Original Message-----
From: CryoNet F [mailto:] On Behalf Of Doug Skrecky
Sent: Friday, May 05, 2006 12:54 PM
To: CryoNet F
Subject: [CN] CR and brain aging


[Tim, when it comes to preservation of cognitive skills, CR could
politely be described as not being on the short list of consistently
effective interventions. However there are a number of people on this list
who practive CR, often at great personal effort, whom I do not wish to
antagonize. Below is one more CR related abstract on brain aging. I would
prefer to end this discussion on CR and brain aging with that. 


For the record I doubt that mild CR in humans would reduce brain function at
all,
but severe CR might be another matter.  I have my own personal medical
library, 
which I have been building for about 20 years, with particular emphasis on
gerontology. 
I recognize that
there is no one web site on the net where the facts behind the science of
gerontology can be accessed at one go. I am considering bringing part of
this library online at some point, in the form of database reports
recounting all anti-aging interventions on all animal species, including
humans. However this would be a very large and time consuming project, and
it may be some time before it will see the light of day.
  In the mean time, I would like to end on a positive note. Effective
interventions against brain aging are currently available, and I will
upload some information regarding one of them to this forum in the near
future.]

Neurobiol Aging. 2004 Mar;25(3):325-32.
Long-term dietary restriction causes negative effects on cognitive
functions in rats.
  Long-term dietary restriction is reported to increase life span and
improve age-related cognitive deficits. The present study shows that the
restriction increases the life span of rats but decreases their cognitive
ability. Thirty-two rats were divided into restricted and ad lib feeding
groups at 2.5 months of age. The restricted rats were kept at a weight of
280g. The restricted rats were poor in performing the Morris water maze
task at 7-12 months. At 17-18 months, they were poor in performing the
delayed matching-to-place task. At 24-27 months, the surviving 13
restricted and 5 ad lib rats performed the spatial discrimination
task. The restricted rats were also poor in performing this
task. Injection of glucose prior to the discrimination task improved
their performance to the level of the ad lib rats. These results suggest
that dietary restriction is beneficial for longevity but has negative
effects on the performance of cognitive tasks, and that the cause of the
negative effects may be a reduced availability of glucose in the
food-restricted aged rats.

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