Caloric Restriction Slows Age-Related Loss of Neurons by Activating SIRT1

Caloric restriction (CR), a dietary regimen known to promote lifespan by retarding the onset of age-dependent diseases, has been found to slow the progressive loss of neurons associated with impaired cognitive capacity by activating the enzyme sirtuin 1 (SIRT1, silent mating type information regulation 2 homolog 1).

Investigators at the Massachusetts Institute of Technology (Cambridge, USA) speculated that since aging is the greatest risk factor for neurodegeneration in the brain, CR might slow the progressive loss of neurons. To explore this possibility they used a genetically engineered mouse model that allowed for temporally and spatially controlled onset of neurodegeneration. These animals were fed a diet decreased by 30% from the normal mouse diet for three months.

Results published in the May 22, 2013, issue of the Journal of Neuroscience revealed that CR significantly delayed the onset of neurodegeneration and synaptic loss and dysfunction, and thereby preserved cognitive capacities.

“We not only observed a delay in the onset of neurodegeneration in the calorie-restricted mice, but the animals were spared the learning and memory deficits of mice that did not consume reduced-calorie diets,” said senior author Dr. Li-Huei Tsai, professor of brain and cognitive sciences at the Massachusetts Institute of Technology. “The question now is whether this type of treatment will work in other animal models, whether it is safe for use over time, and whether it only temporarily slows down the progression of neurodegeneration or stops it altogether