Among scientists, the role of proteins called sirtuins in enhancing longevity has been hotly debated, driven by contradictory results from many different scientists. But new research at Washington University School of Medicine in St may settle the dispute.
Reporting Sept. 3 in Cell Metabolism, Shin-ichiro Imai, MD, PhD, and his colleagues have identified the mechanism by which a specific sirtuin protein called Sirt1 operates in the brain to bring about a significant delay in aging and an increase in longevity. Both have been associated with a low-calorie diet.
The Japanese philosopher and scientist Ekiken Kaibara first described the concept of dietary control as a method to achieve good health and longevity in 1713. He died the following year at the ripe old age of 84—a long life for someone in the 18th century.
Since then, science has proven a link between a low-calorie diet (without malnutrition) and longevity in a variety of animal models. In the new study, Imai and his team 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 vigor and longevity.
"In our studies of mice that express Sirt1 in the brain, we found that the skeletal muscular structures of old mice resemble young muscle tissue," said Imai. "Twenty-month-old mice (the equivalent of 70-year-old humans) look as active as five-month-olds."