More On CR Differences Between Species

As Ouroboros notes, researchers are beginning to uncover differences in the mechanisms of calorie restriction (CR) between species. This lends support to the evolutionary arguments that CR, while demonstrated to be very good for human health, isn't going to extend maximum human life span to the same degree it does in mice. "Decreased IGF-1 levels are associated with increased lifespan. Calorie restriction is also associated with increased lifespan. In rodents, CR is associated with decreased IGF-1 levels, leading to the (still unproven) hypothesis that the effects of CR are mediated by modulation of the IGF-1 axis. In humans, however, the situation is slightly different: As in rodents, the human IGF-1 pathway contains several genes that appear to regulate longevity. The longevity benefits of CR are still under study, but it does appear that certain types of fasting regimens have protective effects against e.g. tumor growth. According to this new study, however, CR has no effect on the levels of functional, circulating IGF-1 [in humans] - so while IGF-1 may regulate longevity and CR may protect against cancer and other age-related maladies, it doesn't appear that CR mediates its effects via IGF-1."

Link: http://ouroboros.wordpress.com/2008/10/22/calorie-restriction-and-igf-1-in-rodents-vs-humans/

Comment Submission

Post a comment; thoughtful, considered opinions are valued. New comments can be edited for a few minutes following submission. Comments incorporating ad hominem attacks, advertising, and other forms of inappropriate behavior are likely to be deleted.

Note that there is a comment feed for those who like to keep up with conversations.