Calorie restriction may prevent and reduce Alzheimer’s in monkeys

A new study directed by Mount Sinai School of Medicine extends and strengthens the research that experimental dietary regimens might halt or even reverse symptoms of Alzheimer’s Disease (AD). The study entitled “Calorie Restriction Attenuates Alzheimer’s Disease Type Brain Amyloidosis in Squirrel Monkeys” which has been accepted for publication and will be published in the November 2006 issue of the Journal of Alzheimer’s Disease, demonstrates the potential beneficial role of calorie restriction in AD type brain neuropathology in non-human primates. Restricting caloric intake may prevent AD by triggering activity in the brain associated with longevity.

“The present study strengthens the possibility that CR may exert beneficial effects on delaying the onset of AD- amyloid brain neuropathology in humans, similar to that observed in squirrel monkey and rodent models of AD,” reported Mount Sinai researcher Dr. Pasinetti and his colleagues, who published their study, showing how restricting caloric intake based on a low-carbohydrate diet may prevent AD in an experimental mouse model, in the July 2006 issue of the Journal of Biological Chemistry.

“This new breakthrough brings great anticipation for further human study of caloric restriction, for AD investigators and for those physicians who treat millions of people suffering with this disease” says Giulio Maria Pasinetti, M.D., Ph.D., Professor of Psychiatry and Neuroscience, Director of the Neuroinflammation Research Center at Mount Sinai School of Medicine and lead author of the study. “The findings offer a glimmer of hope that there may someday be a way to prevent and stop this devastating disease in its tracks.”

AD is a rapidly growing public health concern with potentially devastating effects. An estimated 4.5 million Americans have AD. Presently, there are no known cures or effective preventive strategies. While genetic factors are responsible in early-onset cases, they appear to play less of a role in late-onset-sporadic AD cases, the most common form of AD.

In this new study, Dr. Pasinetti at Mount Sinai School of Medicine, in collaboration with Dr. Donald Ingram at the Laboratory of Experimental Gerontology, National Institute on Aging, NIH, maintained the Squirrel Monkeys on calorie restrictive or normal diets throughout their entire lifespan until they died of natural causes. The researchers found that ~30% calorie restriction resulted in reduced AD type amyloid neuropathology in the temporal cortex relative to control fed monkeys. The decreased AD type neuropathology correlated with increased longevity of related protein SIRT1, located in the same brain region that influences a variety of functions including aging related diseases.

Collectively, the study suggests that the investigation of calorie restriction in non-human primates may be a valuable approach towards understanding the role of calorie restriction in human AD pathology. The present study strengthens the possibility that calorie restriction may exert beneficial effects in delaying the onset of AD. The findings also elucidate the important relationship between the expression of longevity genes like SIRT1 in calorie restriction dietary regimens and mechanisms associated with the prevention of AD.

From Mount Sinaie School of Medicine