Though previous research has mysteriously shown that living at high altitudes lowers your risk of developing diabetes, new research answers the question of why.

High Altitudes, Low Diabetes Risk

U.S. researchers recently studied mouse models of type 1 and type 2 diabetes, finding that as altitude increases and air gets thinner, red blood cells become sponges for glucose, which naturally lowers blood sugar levels. Under chronic low-oxygen conditions, red blood cells showed a threefold increase in glucose uptake.

This helps cells deliver oxygen more efficiently when oxygen is scarce, better regulating blood sugar and making diabetes less likely. Though researchers are still trying to determine how to use this new knowledge, it could potentially be adapted into treatments to prevent or reverse diabetes.

“Red blood cells represent a hidden compartment of glucose metabolism that has not been appreciated until now,” says biochemist Isha Jain from Gladstone Institutes, an independent, nonprofit research organization. “This discovery could open up entirely new ways to think about controlling blood sugar.”

In the experiments on the mice in low-oxygen environments, researchers noticed that they showed lower-than-normal blood glucose levels. They couldn’t determine where the sugar had been sent in the body, however, as it wasn’t in any of the obvious places like the brain, muscle, or liver. Even more interestingly, this effect lasted for weeks after the mice were returned to normal oxygen environments.

Using different imaging techniques and follow-up tests, the team found that the red blood cells were absorbing the glucose and making blood sugar regulation more efficient.

“What surprised me most was the magnitude of the effect,” says biochemist Angelo D’Alessandro, from the University of Colorado. “Red blood cells are usually thought of as passive oxygen carriers. Yet, we found that they can account for a substantial fraction of whole-body glucose consumption, especially under hypoxia.”

The research has been published in Cell Metabolism.