glucose tolerance determines mice lifespan

From: Doug Skrecky (oberon@vcn.bc.ca)
Date: Tue Jun 06 2000 - 12:46:15 MDT


    (The standard rodent chow used by gerontologists does not have
 whole natural foods in it like berries or seeds. Instead cooked
 cornstarch is used, which has an unusually high glycemic index.
 The use of this high GI carbohydrate is partly responsible for
 the high rates of glucose tolerance which occur in lab animals
 that are cared for by gerontologists.
    Another important factor is to be the relative lack of insulin
 sensitising substances, which are readily available in natural
 diets, but which are largely stripped out of the "purified"
 diets used by uninformed gerontologists. These scientists as a
 group well illustrate the dangers of over-specialization, any
 scientist involved in diabetes research would tell gerontologists
 that a phytochemical stripped high glycemic index diet is a
 recipe for adult onset diabetes, and lowering caloric intake of
 such a poor diet can lower risk, via a reduction in glycemic load.
     The so called called anti-aging calorically restricted diet
 appears to be merely an artifact of using a poor diet that
 induces glucose intolerance when fed ad-libitum.
     One rat strain that was fed insulin sensitising chromium
 picolinate had their average lifespan restored to what appears
 to be "normal" values. This is well in excess of that yielded by
 caloric restriction of a purified diet. Chromium picolinate
 has no effect on healthy non-diabetic humans.
     Caloric intake as measured by height has no effect on
 longevity in humans, and weight loss diets do not reduce
 mortality rates in this species. Obesity also has no effect
 on mortality, provided physically fit obese humans are
 compared with physically fit lean humans. In physically unfit
 humans, lean people have a higher mortality than obese.
     These basic facts have been available for quite some time,
 but have been largely ignored by over-specialized gerontologists.
 It is unfortunate, but the primary roadblock to continuing advances
 in gerontology appear to be the incompetence of the gerontologists
 themselves.)

---------- Forwarded message ----------
Title
  Longitudinal determination of
  skin collagen glycation and glycoxidation rates predicts
  early death in C57BL/6NNIA mice.
Source
  FASEB Journal. 14(1):145-56, 2000 Jan.
Abstract
  In 1988, the National Institute on Aging launched a 10-year program aimed at
  identification of biomarkers of aging. Previous results from our laboratory
  showed that pentosidine, an advanced glycation product, formed in
  skin collagen at a rate inversely related to maximum life
  span across several mammalian species. As part of the Biomarkers Program, we
  investigated the hypothesis that longitudinal
  determination of glycation and glycoxidation rates in
  skin collagen could predict longevities in ad libitum-fed
  (AL) and caloric restricted (CR) mice. C57BL/6NNia male mice were biopsied at
  age 20 months and at natural death. Glycation (furosine method) was assessed
  by gas chromatography/mass spectrometry (GC/MS) and the glycoxidation
  products carboxymethyllysine (CML) and pentosidine were determined by GC/MS
  and HPLC, respectively. CR vs. AL significantly (P<0.0001) increased both
  mean (34 vs. 27 months) and maximum (47 vs. 31 months) life spans.
  Skin collagen levels of furosine (pmol/&mgr;mol lysine) were
  approximately 2.5-fold greater than CML levels and 100-fold greater than
  pentosidine. Individual accumulation rates modeled as linear equations were
  significantly (P<0.001) inhibited by CR vs. AL for all parameters and in all
  cases varied inversely with longevity (P<0.1 to <0.0001). The incidence of
  three tissue pathologies (lymphoma, dermatitis, and seminal vesiculitis) was
  found to be attenuated by CR and the latter pathology correlated
  significantly with longevities (r=0.54, P=0. 002). The finding that markers
  of skin collagen glycation and glycoxidation rates can
  predict early deaths in AL and CR C57BL/6NNia mice strongly suggests that an
  age-related deterioration in glucose tolerance is a life span-determining
  process.



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