Fight Aging!

A great paper in Cell (full text freely available for now) dives into the role of mitochondria in relation to aging, calorie restriction (CR) and sirtuins: "CR can exert a positive effect on mitochondria, boosting mitochondrial activity and hence providing at least some of the salutary effects of CR. ... CR and sirtuins upregulate the activity of mitochondria in different organisms. ... There is ample evidence that damage to mitochondria increases progressively with age. This has been observed in the form of the accumulation of mutations in mitochondrial DNA and a decline in the activity of mitochondrial enzymes and components of the electron transport chain. ... A higher pool of functional mitochondria may ameliorate tissue damage simply by buffering [cells] against the gradual decline in the ability to produce energy as mitochondria become damaged during aging. One may well wonder why mitochondrial number is not normally set to a higher level during ad libitum feeding to forestall this decline. It is important to remember that aging occurs postreproductively and is nonadaptive. Thus, under normal conditions, mitochondrial number and function will only fall sway to selective pressure until the reproductive period has been completed. ... By this logic, CR and perhaps other stressors may impose a new selective landscape in which robust somatic maintenance, rather than reproduction, is now at a premium and mitochondrial biogenesis favored."

Link: http://www.cell.com/content/article/fulltext?uid=PIIS0092867408000627