Longevity Drug May Not Slow Aging
The immunosuppressive drug rapamycin might increase longevity, but new research suggests that it has limited effects on aging.
Previous studies revealed that the drug, commonly used to prevent rejection in organ transplantation, extended the lifespan of mice, even after the animals were treated in old age.
However, researchers from the current study say that it is unclear if the extension of life also correlates with prolonged health and vigor.
The study, published in the Journal of Clinical Investigation, wanted to evaluate age-associated characteristics in mice treated with rapamycin (Sirolimus).
Lead researcher Dan Ehninger and colleagues at the German Center for Neurodegenrative Diseases found that the drug significantly improved memory and spatial learning and reduced thyroid follicle size body fat in older mice. However, researchers found that these effects were also seen in young mice treated with the drug, indicating an age-independent drug effect.
The drug also seemed the decrease the prevalence of cancer, a common cause of mouse mortality, in older mice.
However, researcher found that rapamycin ad no effect on several age related symptoms, including cardiovascular and liver function, loss of muscle mass, strength retention, or balance.
Researchers said the findings suggest that rapamycin treatment may increase lifespan through reduction of cancer rates. They also note that the drug may be useful for treating some age-related conditions.
In an accompanying article, Arlan Richards of the University of Texas Health Science Center at San Antonio says that the findings suggest researchers should consider studying the effect of rapamycin on age related neurodegenerative diseases like dementia and Alzheimer's disease.