FLICKR, DANUpdate (September 2, 2015): This study has been retracted.
Bears pack on the pounds—up to twice their weight—before hibernating. Being obese and sedentary can lead to insulin resistance and, eventually, type 2 diabetes in humans and other species, but grizzly bears dodge the disease. A study published this week (August 5) in Cell Metabolism showed the bears’ insulin sensitivity is reversed during hibernation.
Lynne Nelson of Washington State University in Pullman and her colleagues studied weight fluctuations in six captive grizzly bears over the course of a year to understand how the animals adapted. They discovered that, unlike humans, the bears remained highly sensitive to insulin even at their heaviest: a tiny dose that a person might take proved nearly lethal to the 700-pound grizzlies.
“The results were so different from what we see ...
