Long-lived dwarf lemurs offer clues to aging

A team of researchers is trying to obtain clues to aging from long-lived lemurs.

When Jonas the lemur died in January, just five months short of his thirtieth birthday, he was the oldest of his kind. A primate called a fat-tailed dwarf lemur, Jonas belonged to a long-lived clan. Dwarf lemurs live two to three times longer than similar-sized animals.

In a new study, Duke University researchers combed through more than 50 years of medical records on hundreds of dwarf lemurs and three other lemur species at the Duke Lemur Center for clues to their exceptional longevity.

The conventional wisdom in longevity research is that smaller species live shorter lives than larger ones. The researchers found an exception to this pattern in a group of hamster-sized lemurs with a physiological quirk, they are able to put their bodies in standby mode.

How long the animals live and how fast they age correlates with the amount of time they spend in a state of suspended animation known as torpor, the data show. Hibernating lemurs live up to ten years longer than their non-hibernating cousins.

Dwarf lemurs like Jonas go into a semi-hibernation state for three months or less in captivity, but even that seems to confer added longevity, said study co-author Sarah Zehr.

Hibernating dwarf lemurs can reduce their heart rate from 200 to eight beats per minute. Breathing slows, and the animals' internal thermostat shuts down. Instead of maintaining a steady body temperature, they warm up and cool down with the outside air.

It may also be that torpor increases longevity by protecting cells against the buildup of oxidative damage that is a normal by-product of breathing and metabolism, said study co-author Marina Blanco.

Blanco added that if your body is not working full time metabolically-speaking, you will age more slowly and live longer. Because lemurs are more closely related to humans than mice are, the research may eventually help scientists identify anti-aging genes in humans.