Rapamycin, a drug that has been found to increase max life expectancy in mice, has drawn interest from researchers in hopes that the drug slows the aging process. But some German researchers find that rapamycin works by suppressing tumors.
Bonn, Germany, July 25, 2013 – The drug rapamycin is known to increase lifespan in mice. Whether rapamycin slows down aging, however, remains unclear. A team of researchers from the German Center for Neurodegenerative Diseases (DZNE) and the Helmholtz Zentrum München has now found that rapamycin extends lifespan - but its impact on aging itself is limited. The life-extending effect seems to be related to rapamycin’s suppression of tumors, which represent the main causes of death in these mouse strains. The findings are reported in the current issue of the “Journal of Clinical Investigation” (published online on July 25, 2013).
Of course tumor suppression is a good thing. But a general slowing of the aging process would have greater utility for extending human life expectancy. An even better method to deal with aging: repair and replace aged tissue.
The rapamycin discovery in 2009 seemed like a big deal at the time.
. In 2009, US scientists discovered another effect: Mice treated with rapamycin lived longer than their untreated counterparts. “Rapamycin was the first drug shown to extend maximal lifespan in a mammalian species. This study has created quite a stir,” says Ehninger.
Rapamycin's seems to change metrics of aging traits via mechanisms that do not involve a slowing of the aging process.
Together with scientists from the Helmholtz Zentrum München and other colleagues, Ehninger’s group investigated if rapamycin influences aging in mice. The results are sobering: “Our results indicate that rapamycin extends lifespan, but it has only limited effects on the aging process itself,” is Ehninger’s summary of the findings. “Most aging traits were not affected by rapamycin treatment. Although we did observe positive effects on some aging traits, such as memory impairments and reduced red blood cell counts, our studies showed that similar drug effects are also seen in young mice, indicating that rapamycin did not influence these measures by slowing aging, but rather via other, aging-independent, mechanisms.”
Cancer is my biggest death fear. But you might be surprised to learn (as I was just now when I did the calculation) that out of the 2,468,435 people who died in the United States in 2010 only 23.2% died from cancer.
Note the third place position for respiratory diseases as well as the ninth place position for flue and pneumonia. Infections kill people whose immune systems have gotten too old and feeble.
An aged immune system also probably boosts the risk of cancer by because old immune cells are less able to attack and kill aged abnormal cells that are at increased risk of going cancerous. Methods to rejuvenate the immune system would cut both cancer and infectious disease deaths.
|Share |||Randall Parker, 2013 July 25 10:00 PM|