Starve a mouse and its aging processes slow to a crawl. Same thing goes for yeast and beast alike – the effects of calorie reduction (CR) on longevity are conserved throughout the eukaryote evolution.
The benefits of caloric reduction in mammals have grabbed the headlines of mainstream media routinely in recent years. The July 10th issue of Science provided the most recent support, when a team of University of Wisconsin researchers published compelling data on how calorie restricted rhesus monkeys could maintain their dashing good looks and avoid age related maladies better than their well fed counterparts.
A recent review written by chromatin gurus, Alejandro Vaquero and Danny Reinberg, highlights the ways chromatin can flex its regulatory muscle during in calorie restricted diets. Many of the pathways – through both energy deprivation and nutrient deprivation – converge on chromatin, explain the duo. And it’s not just protecting the genome from reactive oxygen species (free radical) damage, either. CR has a direct affect on chromatin structure as well.
CR increases the ratio of NAD+ to NADH, which activates the Surtuin family of enzymes (SirT1 – SirT6), and downregulates the PARPs (Poly-(ADP-ribosyl) transferases). This favors heterochromatin formation and boosts DNA repair activity. CR also inhibits the nutrient-sensing target of rapamycin (TOR), which has a similar effect.
Of course this is just an appetizer of what’s going on with chromatin in CR. You can get the full course at Genes & Development, July 2009 AND if you’re ready to dive into how diet and epigenetics intersect, be sure to check out the grant announcements the NIH just released last week for Diet, Epigenetics events, and Cancer Prevention.