X-Message-Number: 6189
Date: Sun, 12 May 1996 17:09:06 -0400 (EDT)
From: Ben Best <>
Subject: SCI.CRYONICS Re: Is Late-Life Caloric Restriction Beneficial?

      Douglas Skrecky has cited a pilot study made with 17 controls and
18 calorie-restricted rats (who were also subject to protein restriction)
and then goes on to say:

>            However be that as it may, this experiment is in line with
>  others which have failed to obtained any lifespan extension in older
>  the same holds true for humans then three conclusions can be drawn given
>  that 18 months in Long Evans rats corresponds roughly to 18/30 * 75 = 45
>  years in human terms. 
>  #1.  Humans older than 45 years will not extend their lives by initiating
>  caloric restriction except by a reduction in disease risk. An "AN" diet
>  rather than a CRAN diet would here be more appropriate. 
>  #2.  Calorie restriction initiated in younger animals is MORE EFFECTIVE
>  than was hitherto realized since all of the lifespan extension achieved
>  was due to restriction over a more limited time frame. Humans younger
>  than 45 years have an added incentive since full benefits of CRAN are
>  obtained with a restriction over a shorter time period - up to 45 years
>  of age. 

     Douglas is evidently unaware of the work by Drs. Weindruch and Walford.
These men have made themselves the foremost names in Caloric Restriction
research by the extreme care they have taken to ensure Adequate Nutrition
and good care of laboratory animals (including ensuring that animals 
cannot eat their own shit). In particular, they have made ground-breaking
discoveries concerning the benefits of Caloric Restriction with Adequate
Nutrition (CRAN) begun in adulthood.

    As an example, I cite Study 1 on Table 2.7 of THE RETARDATION OF AGING
AND DISEASE BY DIETARY RESTRICTION by Richard Weindruch and Roy Walford 
(1988). This study involved 68 control mice and 67 CRAN mice (consuming
60% of the number of calories of the controls). A comparison was made 
between controls, Adult Dietary Restriction [(ADR) initiated at 14 months]
and Early Dietary Restriction [(EDR) initiated at 1 month]. The results:

                     Average Lifespan   Maximum Lifespan
                        (months)           (months)

          Control          36                 41
              ADR          39                 45

              EDR          43                 50

    Taking 115 years as the human maximum lifespan, the ADR animals began
their CRAN at the equivalent of 39 years of age and lived about 10% longer.

    Douglas latches on to age 45 as the age at which CRAN can no longer
be of benefit. What does he think happens between 39 and 45, some kind
of "aging menopause"? No, human physiology does not change that much 
with aging.

    In my opinion, the benefits of CRAN are mainly due to: (1) reduced
free-radical oxidation damage and (2) reduced non-enzymatic glycosylation.
I believe that these benefits can be had at almost any age. The earlier
the better (after development), but I think its never too late to get
*some* benefit (provided CRAN is applied in a non-traumatic manner).

    Mice and humans are different, of course. CRAN is most beneficial
when begun before puberty, but by my calculations 1 month for a mouse
corresponds to 2.8 years for a human. Few humans reach puberty at this
age. More seriously, I think that the benefits of CRAN for average 
lifespan are much greater for humans than for mice. Humans are more
vulnerable to cardiovascular disease, which cuts an average of 14 years
from life. Moreover, the number one risk factor for stroke is high
blood pressure and the best way to lower blood pressure is to lose 
weight. Since I began practicing CRAN I have had a significant decline
in my resting blood pressure and heart rate. There may be yet another
benefit insofar as a major cause of senile dementia is sub-clinical strokes.

    I believe that we are on the cusp of radical breakthroughs in the 
capacity of science to stop aging and achieve suspended animation of
the brain. If I can extend my life even an additional 5%, that may be
the difference between gaining these benefits or "missing the boat".

                              -- Ben Best ()

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