Stay Cool, Live Longer

It's been a good month for lab rats ...

First, we hear that they've been fed a steady diet of red wine and have found that it helps extend their life spans. Now, on top of that, a bit of a chill seems to prolong their mortality even more.

Jia-Rui Chong of the Los Angeles Times has details on the latter development:

A new study on genetically engineered mice appears to offer a novel way to live up to 20 percent longer: chill out.

Scientists engineered mice to have body temperatures 0.5 to 0.9 degrees lower than normal mice. Female experimental mice lived a median of 662 days, about 112 days longer than normal female mice. Male experimental mice survived a median of 805 days, 89 days longer than their normal counterparts.

"We have identified that a small but continuous reduction of temperature can have a beneficial effect in life span and aging," said the study's lead author, Bruno Conti, a biologist at Scripps Research Institute in La Jolla, Calif. "It is equivalent to seven or eight years of human life, so it is not bad."

Scientists have known for decades that restricting calories in a diet prolongs life span, and animals with restricted calories tend to have lower body temperatures. Conti wanted to know if decreasing body temperature alone could have a beneficial effect on longevity.

Earlier studies looked at animals such as roundworms whose body temperature depends on their environment. Conti said this is the first study to alter the temperature of warm-blooded animals.

The 79 experimental mice did not appear significantly different from the 67 normal mice, eating about the same amount of food.

Conti acknowledged the technique is "not terribly practical" for human beings yet.

But, he added, "If we figure out how the thermostat works, one could think there could be the development of a pharmacological approach."