2) One of the most amazing aspects of dietary restriction is that the
health and longevity benefits have been found in ALL the animal species
studied, including worms, insects, mollusks, spiders, fish, reptiles,
and (of course) mammals.  The implications of this finding are profound,
meaning wherever the black box (the mechanism of dietary restriction)
resides, either it is at a basic physiological "core," or that it impacts
basic physiology at a core level (probably some degree of both, tilted
towards the later).  Because we are leaving the question of mechanism at
a black box level, it really doesn't matter.  Whatever the mechanism, it
is clear it profoundly impacts animals of all types at a very basic
physiological level.
 
This creates some important implications for ferrets.  While there is
always a minor chance that ferrets can be an exception to the rule, with
each species added to the list of animals that have positive benefits
to dietary restriction, those chances are diminished.  Considering
the health benefits of dietary restriction have been found in lower
invertebrates, insects, gastropods, arthropods, reptiles, birds, and
mammals, it becomes a stretch to suggest that ferrets will be the
exception.  Indeed, because DR benefits are seen in such a diverse range
of animals, ANY exception would be unusual and would signal an extreme
modification of basic physiology.
 
This overwhelming body of evidence has convinced most scientists that the
effects of dietary restriction are so common among animals in general
(and mammals in particular), that it is assumed it is a basic
physiological principle UNLESS PROVED OTHERWISE.  Consider these quotes:
 
Science (1999): "...Aging resulted in a differential gene expression
pattern indicative of a marked stress response and lower expression
of metabolic and biosynthetic genes.  Most alterations were either
completely or partially prevented by caloric restriction, the ONLY
intervention known to retard aging in mammals."
 
Journal of Investigative Dermatology (1998): "...Calorie restriction (CR)
reduces cancer incidence, improves health by delaying age-related
declines in physiologic measures, and extends both median and maximal
life span."
 
Mutation Research (1996): "There is an impressive body of evidence
demonstrating that dietary restriction, particulary in the form of
caloric restriction (CR), or energy restriction, is effective in
retarding the aging process, as well as in substantially increasing
life span."   "...The physiological processes modulated by CR have
been highly conserved in evolution...."
 
With each species added to the list, the likelihood that ferrets will be
an exemption becomes increasingly remote.  Say what you will about
hypotheses and proof, there comes a moment when you realize a fundamental
truth; physiological principles tend to be universal.  Why?  Because
basic physiological principles are highly conserved: even when a species
evolves a modification to the system to survive specific environments or
diets, the basic core physiology remains essentially unaltered.
 
Dietary restriction is common in animals in general, and in mammals
in particular.  While neither actually proves DR would have benefical
effects in ferrets, the evidence is mounting.  It is clear that DR
impacts animals at some basic physiological level, so basic that it
impacts animals from a wide and diverse evolutionary history.  This
makes it unlikely that ferrets would be an exception to the rule.
 
Bob C
[Posted in FML issue 3959]