The report, published in Cell Metabolism, found mice with a deficiency that prevented them from eliminating physiological reactive oxygen species -- free radicals linked to aging -- did not become insulin resistant on a high-fat diet as they otherwise would have. When those animals were given an anti-oxidant that fights those reactive oxygen species, those benefits were lost, leaving the mice with more signs of diabetes.
The researchers suggest low levels of reactive oxygen species -- in particular hydrogen peroxide -- might protect against diabetes by improving the body's response to insulin signals.
"Our studies indicate that 'physiological' low levels of reactive oxygen species may promote the insulin response and attenuate insulin resistance early in the progression of type 2 diabetes, prior to overt obesity and hyperglycemia," study leader Tony Tiganis of Monash University, Victoria, Australia, said in a statement. "In a way, we think there is a delicate balance and that too much of a good thing -- surprise, surprise -- might be bad."