Fat Grizzly Bears Staying Healthy and Diabetes-Free


By Melissa Koontz

There’s no denying that grizzly bears are huge animals and gain even more weight when getting ready to hibernate (they can gain 100 pounds before hibernation). If humans don’t take care of themselves, it can lead to weight gain or other serious issues such as diabetes. Grizzly bears can stuff their stomachs and then sleep like there’s no tomorrow knowing that they don’t have to worry about their diet or diabetes. New research, published in the August 2014 issue of Cell Metabolism, sheds some light into this seemingly unfair phenomenon.

Discoveries Lead to Diabetes Preventation for Humans

When humans gain weight, fat, liver and muscle tissues become less sensitive to insulin. The pancreas must then produce more and more insulin to control blood sugar until it eventually shuts down causing diabetes.

Unlike humans, bears remained healthy year-after-year even after such extreme weight gains preparing for hibernation.

Dr. Kevin Corbit, a senior scientist at California-based drug company, Amgen, working with the researchers at the Washington State University Bear Center in Pullman, looked at the blood metabolism of the grizzlies. They analyzed many key molecules in liver, fat and muscle cells of the bears before, during and after hibernation – in October, January and May.

Corbit and the researchers found a key protein called PTEN, which controls insulin sensitivity and fights weight gain. When the bears hibernated, their bodies shut down this protein. If they didn’t have this protein, the bears wouldn’t be able to store as much sugar in their bodies.

If the same pathway could be shutting off PTEN in humans, diabetes could be treated. A study showed that when one gene for PTEN was missing in a person, they were less likely to develop metabolic or cardiovascular disease even as they gain weight. The results imitated the bear-like qualities. Other diseases like cancer can be developed because the PTEN levels are reduced, but if scientists can shut them down in fat cells, like the grizzlies, these side effects might be reduced.

More Harm Than Good?

Although this is all very exciting news for us humans, in order to support the bears finding and connecting it to helping human diabetes, more evidence is needed.

Shutting down PTEN in humans might be able to help with diabetes, but it might cause other issues like arthritis or even weight gain. We just need to be sure that this would help more than hurt and target the correct patients.

“Moving forward, this more sophisticated understanding of the relationship between diabetes and obesity should enable researchers not only to develop therapies targeting these mechanisms, but also to identify the appropriate patients to whom these therapies should be targeted,” said Corbit.

Extension Questions

  • Which protein controls insulin sensitivity and fights weight gain?
  • On average, how much does a grizzly bear weigh?