Calorie restriction is a powerful weapon to use against life's aging diseases, forget magic bullets and take responsibility for what you put in your mouth, even when it is your foot.
Research just in from the American Institute of Cancer Research (AICR) suggests that people avoid more of the aging diseases by intermittently restricting calories rather than permanently restricting calories, of course eating whatever you like offers the worst outcome. In this study on the development of breast cancer the mice that ate an unlimited number of calories developed 71.00% breast tumours, the mice that had permanently restricted calories (50% restriction) developed 35.4% tumours and intermittent calorie restricted mice only developed 9.1% tumours. The calorie restriction works on restricting serum insulin-like growth factor.
1: Cancer Prev Res (Phila Pa). 2009 Aug;2(8):712-9. Epub 2009 Aug 3.Click here to read Links
Serum insulin-like growth factor-i and mammary tumor development in ad libitum-fed, chronic calorie-restricted, and intermittent calorie-restricted mmtv-tgf-alpha mice.
Rogozina OP, Bonorden MJ, Grande JP, Cleary MP.
The Hormel Institute, University of Minnesota, 801 16th Avenue Northeast, Austin, MN 55912, USA. mpcleary@hi.umn.edu
The effect of chronic (CCR) and intermittent (ICR) caloric restriction on serum insulin-like growth factor (IGF)-I levels and mammary tumor (MT) development was investigated. Ten-week-old MMTV-TGF-alpha female mice were assigned to ad libitum-fed (AL; AIN-93M diet), ICR [3-week 50% caloric restriction using AIN-93M-mod diet, 2x protein, fat, vitamins, and minerals followed by 3 weeks of daily 100% AL consumption of AIN-93M ( approximately 75% of AL for each 6-week cycle)], and CCR (calorie and nutrient intake matched for each 6-week ICR cycle) groups. Half of the mice from each group were sacrificed at 79 (end of restriction) or 82 (end of refeeding) weeks of age. Serum was obtained at euthanasia and in cycles 1, 3, 5, 8, and 11. MT incidence was 71.0%, 35.4%, and 9.1% for AL, CCR, and ICR mice. ICR-Restricted mice had significantly lower terminal serum IGF-I and IGF-I/IGF binding protein-3 (IGFBP-3) ratio than CCR, ICR-Refed, and AL mice. There were no differences in terminal IGFBP-3. Final body, internal, and mammary fat pad weights correlated positively with IGF-I and negatively with IGFBP-3. Few changes were found for protein expression of IGF-IRalpha and IGFBP-3 in mammary tissue and MTs. During the study, IGF-I levels of ICR-Restricted mice were reduced, whereas refeeding allowed partial recovery. For all groups, elevated IGF-I levels preceded MT detection, although not all values were significant versus mice without MTs. However, the specific role of IGF-I in the protective effect of calorie restriction remains to be determined. These results confirm that ICR prevents MT development to a greater extent than CCR.
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