What’s the name of this creature? Technically, it’s Ursus arctos horribilis—better known as the grizzly bear. And new research published in Cell Metabolism provides data to back up what animal scientists have long observed: Bears can pack on the pounds while maintaining perfect health. The study, led by O. Lynne Nelson, professor of cardiology at Washington State University’s Veterinary Teaching Hospital, monitored grizzly bears during their normal hibernation cycle. Researchers took special note of bears’ responsiveness to insulin, the hormone that facilitates the absorption of sugar from the bloodstream. MORE: How To Lose Belly Fat Here’s the thinking: When everything’s working properly, cells are sensitive to the presence of insulin. They know it means there’s sugar in the bloodstream to absorb and use for energy. But in type 2 diabetes, cells become resistant to insulin—resulting in blood sugar levels that are dangerously high. In humans, obesity and damaging insulin resistance go hand in hand. In bears, the study found, they don’t. In fact, just before hibernation, our ursine friends can reach a measurement of 30–40% body fat without developing diabetes. How do they manage it? Researchers discovered that throughout the hibernation cycle, bears’ fat cells change their response to insulin. During summer and fall, they’re insulin sensitive, and during hibernation, they’re insulin resistant. Most importantly, this on-off switch is confined only to the fat cells the bears have built up for winter sleep—it does not affect other organ systems in their bodies. In other words, bears have found a way to corral negative effects of insulin resistance, and, in doing so, avoid disease. “They don’t have signs related to high cholesterol, cardiac disease, or diabetes,” Nelson says. It’s a healthy form of obesity.” There’s still much more to discover about this cellular activity—including, perhaps, a way for human treatments to borrow from the grizzly’s mechanisms. “Bears have very specific ways of handling some of the problems that we face,” Nelson says. “None of the things that we found are new. They’re not new hormones or tissues or functions or receptors. They’re all the same that you and I have. The bears are just using them more efficiently.” Just your average bear? Not a chance. Grizzlies, color us impressed. MORE: 50 Little Tweaks To Get A Flatter Belly
