Further Explorations in Calorie Restriction
Via Science News, something for those of us interested in the biochemistry of calorie restriction: "Less food doesn't always mean less energy. Restricting the diet of yeast cells makes them live about 30 percent longer than normal, scientists have known. But new research shows that these calorie-restricted cells make just as much ATP - the energy currency of cells - as do yeast cells fed a normal diet. The cells have just as much energy available, so [it's] not a starvation; it's just a specific sort of remodeling of the cells' metabolism in a way that also causes the organism to live longer ... the cells cut back on making lipids and instead rerouted energy to making ATP ... Normally, lipid molecules such as free fatty acids accumulate in yeast cells. This impairs the cells and can even cause them to self-destruct. So diverting energy away from making these lipids could help explain why calorie restriction prolongs the cells' lifespan. ... that some of the changes in the cells stimulate mitochondria, the 'power plants' of cells. As a consequence, these mitochondria churn out free radicals such as hydrogen peroxide at doses too low to do much damage to the cells but high enough to activate the cells' stress-response proteins. These groups of proteins go around fixing damage in the cells, a kind of house cleaning that can also help the cells live longer."
Link: http://www.sciencenews.org/view/generic/id/35835/title/Live_long_and_alter