The many ways of aging have been and continue to be investigated. For this reason, over many years, several studies have resolved some of the genetic details underlying aging processes. It resulted in the identification of a yeast gene known as Sir2, which is a longevity modulator. Sir2 and SIRT1 are the mammalian homologs of yeast genes. Sirtuins (including SIRT1) play an important role in aging of the brain and the metabolic regulation pathway in mammals. Aging in the brain is caused by the loss of neurophysiologic functions due to neurodegeneration. The sirtuin family plays a central role in the beneficial effects of calorie restriction (CR). CR is linked with an increase in life span and decrease in the risk of diseases related to the brain. Sirtuins may be helpful for us in studying the process of aging and treatment of diseases related with aging.