Following a low-glycemic diet could help alleviate autism symptoms, a study finds.

A low-glycemic diet, often recommended for people with diabetes, eliminates bread, high-sugar, and processed foods that result in blood sugar spikes. The eating plan emphasizes healthy whole foods such as vegetables, fruits, and whole grains.

Scientists at the Salk Institute for Biological Studies in La Jolla, Calif., used mice specially bread to display autism-like symptoms to learn whether a diet low in dicarbonyl methylglyoxal (a common byproduct of sugar metabolism) would reduce autism symptoms.

They fed pregnant mice either the high or low glycemic index diet and kept their offspring on the same diet after birth and weaning, because their brains were still forming crucial connections.

The two groups of animals consumed the same number of calories and were identical in weight. But mice that ate a high-glycemic diet showed all of the expected behavioral symptoms of autism. Their social interactions were impaired, they repeated actions that served no apparent purpose, and they groomed extensively.

Mice on a low-glycemic diet showed no such symptoms.

The number of children diagnosed with autism -- a spectrum of disorders characterized by social avoidance, repetitive behaviors and difficulty communicating -- has risen dramatically over the past two decades for reasons that are unclear.

Although preliminary and not yet tested in humans, these findings might offer clues that changes in dietary lifestyle may be one potential explanation for the increase in autism, the researchers said.