X-Message-Number: 13853 Date: Tue, 6 Jun 2000 11:45:47 -0700 (PDT) From: Doug Skrecky <> Subject: glucose tolerance determines mice lifespan (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. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13853