Dr. Shin-ichiro Imai and colleagues from Washington University School of Medicine have presented the first evidence of a naturally produced compound that extends life without imposing dietary restrictions. The research was reported in the Sept. 3, 2013, issue of the journal Cell Metabolism.
The researchers began by finding that the sirtuin protein called Sirt1 produced specific changes in the hypothalamus of test mice as long as their calorie intake was restricted. The test mice that ate a calorie restricted diet were observed to have increased skeletal muscle strength that translated into extended life.
The researchers examined mice that had been genetically altered to produce the Sirt1 protein in the brain and mice that had been genetically modified to express the Sirt1 protein effect only in the skeletal muscles.
Only the mice that were modified to over express the Sirt1 protein in their brain demonstrated the same longevity responses as mice that were kept on a restricted calorie diet. The over expression of the Sirt1 protein produced longevity without any need for dietary restrictions.
In human terms the effect of the Sirt1 protein’s activity in the brain added 14 years to female’s lives and seven years to male’s lives. Added benefits included deeper sleep for both sexes and a delayed rate of death from cancer.
The scientists express an expectation of being able to moderate the genes identified and the activity of the Sirt1 protein in humans to produce the same longevity effects.