One of the goals of the Calorie Restriction with ON lifestyle is to activate Sirtuin 1 (SIRT1). The SIRT1 enzyme that has been positively linked to longevity. SIRT1 affects a variety of cellular processes including metabolism, stress response, cell death, and inflammation. Basically, when our cells come under stress from aging, damage, poor diet, or an infection (to name a few) they have to make a decision: try and repair or die.
On a basic level, the SIRT1 enzyme influences the cell to repair itself rather than die. It’s one of the body’s natural responses to stress. So (theoretically), if we can activate this gene then we should be able to help our cells live longer and healthier. Studies have shown than the SIRT1 gene is turned on in mammals following a CRON diet. It is possible that much of the CR effect comes from the activation of this gene. The compound Resveratrol is also implicated in the activation of SIRT1, but some results are inconsistent (resent studies may indicate resveratrol indirectly activates SIRT1 depending on other factors). I’m sure many people would like to get CR in a pill, but I’m not going to jump on that just yet.
Currently, CRON is the only diet documented to increase both the median and maximum lifespan across a wide range of species. Keep in mind there are many things you can do to stay healthy, but CRON is not only about being healthy. Calorie restriction is about maximizing your life span. To have a healthy life, eating well and living an active, low stress life are definitely very important. However, only CR has reported longevity benefits as well as health benefits, and the activation of SIRT1 may be a major factor in those results.
References:
http://en.wikipedia.org/wiki/Calorie_restriction#Positive_effects
http://en.wikipedia.org/wiki/Sirtuin_1#Activators
http://www.sciencenews.org/view/generic/id/41044/title/Anti-aging__A_little_stress_may_keep_cells_youthful
http://www.sciencemag.org/cgi/content/full/310/5754/1641
http://www.nature.com/nrm/journal/v6/n4/abs/nrm1616.html
http://genesdev.cshlp.org/content/22/13/1753.full
