Why do bats live so long? And how can we live longer too?

Ars Technica tries to discover what it is about bats that could help us humans live longer, healthier lives:

For the most part, as the size of the mammal goes up, its metabolism slows down and its longevity increases. There are exceptions, and we are one of them. We’re much longer lived than other mammals with a similar body mass. Bears, which tend to weigh quite a bit more than us, rarely live past 30.

But a new paper about longevity includes a remarkable statistic: “Nineteen species of mammals live longer than humans, given their body size, of which 18 are bats.”

The Irish-French team behind the new study notes that a species called Brandt’s bat weighs only about seven grams, yet lives for over 40 years in the wild.

To take a systematic look at what’s going on, the researchers worked with a related species of bats that can live for over 25 years. The bats were captured, the researchers took blood samples, tagged them, and then released them. Six years later, they repeated the process, getting data for 100 different bats and opening a window into how the bats had changed during aging. They tracked which genes were active at each time point, allowing them to track how the bats’ blood cells were changing with age.

… [R]esearchers looked for differences in gene activity that were present in the majority of the samples at the later date. These were relatively small in number; the scientists estimate that only about nine percent of the total differences in gene activity are associated with aging.

But within that nine percent were some genes that stood out. Most of the age-related difference could be accounted for by 100 genes with the largest changes in activity. And these were enriched in genes involved in processes that keep cells healthy: repairing DNA damage and digesting and recycling damaged components figured prominently. Other genes with increased activity help stop cells from dividing. And the bat maintains its chromosome ends through a pathway that doesn’t seem to involve telomerase, the enzyme most frequently associated with that activity.

…[T]hey found that the bats increase the levels of micro-RNAs that shut down cell division, while lowering the levels of those that promote it. This is in keeping with the other evidence that bats manage to limit cancer incidence with age.

You can read the original study here.