X-Message-Number: 27883
Date: Sun, 30 Apr 2006 09:46:01 -0700 (PDT)
From: Doug Skrecky <>
Subject: CR and brain aging

  [Considering the global effects of CR, one might be excused from
assuming that this intervention would have far more dramatic effects on
animal longevity than it does. A number of studies in adult animals have
found no longevity advantage to CR at all. One possible explanation for
these unexpected findings may be due to CR  not affect the aging of the
central nervous system. Since the energy supply of this tissue is
preferentially preserved, caloric consumption by the brain can not
be restricted due to simple dietary alterations.
  However if the functioning of the central nervous system is preserved
by whatever means, then this might have a far more powerful effect on
longevity through prolonged maintainance of the stem cell niche, via
continued exposure to a youthful (brain-derived) hormonal
environment. This might explain of the potent antiaging effect of
chromium picolinate.
  The following abstract illustrates the lack of effect of CR on brain

Ann N Y Acad Sci. 2004 Jun;1019:269-73.
Measurement of the 4,834-bp mitochondrial DNA deletion level in aging rat
liver and brain subjected or not to caloric restriction diet.
  Several studies have demonstrated an age-related accumulation of the
amount of a specific 4834-bp mitochondrial DNA (mtDNA) deletion in
different tissues of rat (liver, brain, and skeletal muscle). We
investigated the influence of a caloric restriction diet (CR) on a
selected age-associated marker of mtDNA damage, as the 4834-bp deletion,
using quantitative real-time PCR. The mtDNA deleted level has been
determined with respect to the mitochondrial D-loop level, using specific
primers and TaqMan probes for each target. In liver we found an
age-related increase of the deletion level (twofold) that was reversed and
brought back to the adult level by a CR diet. On the contrary, in the
brain the age-related increase of the deletion level (eightfold) was not
affected by CR at all. The different effect of the CR on the deletion
level in liver and brain might be a further element supporting
the tissue-specificity of the aging process.

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=27883