The researchers found that the median life span of mice in the study was extended by 16 percent for females and 9 percent for males, however, translated to humans, this could mean an extra 13 or 14 years for women, making their average life span almost 100 years. For men, this would add another seven years, increasing their average life span to the mid-80s.
Shin-ichiro Imai, MD, PhD, and his colleagues at Washington University School of Medicine in St. Louis have shown how Sirt1 prompts neural activity in specific areas of the hypothalamus of the brain, which triggers dramatic physical changes in skeletal muscle and increases in vigour and longevity.
The researchers studied mice that had been genetically modified to overproduce Sirt1 protein and found that only the mice that overexpressed Sirt1 in the brain (called BRASTO) had significant lifespan extension and delay in aging, just like normal mice reared under dietary restriction regimens.
In addition to positive skeletal muscle changes in the BRASTO mice, the investigators also observed significant increases in night-time physical activity, body temperature and oxygen consumption compared with age-matched controls.
The study is published in journal Cell Metabolism.