Consuming too much sugar can eat away your intelligence, according to a study by scientists that showed how a steady diet of fructose sapped lab rats’ memories. The study appeared in the Journal of Physiology last month.

Researchers at the University of California Los Angeles (UCLA) gave two groups of rats a water solution laced with fructose instead of drinking water for six weeks. One group was supplemented with brain-boosting omega-3 fatty acids in the form of flaxseed oil, while the other was not.

Before the sugar drinks started, the rats were enrolled in a five-day training session in a complicated maze. After six weeks on the sugar solution, they were placed back in the maze to see how they fared.

The group that didn’t receive the omega-3s ran the maze much slower, forgetting much of a route it had already learned.

“Their brain cells had trouble signaling each other, disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier,” Fernando Gomez-Pinilla, professor of neurosurgery at UCLA’s David Geffen School of Medicine, said in the study.

Gomez-Pinilla noted that the rats that weren’t fed omega-3s also developed signs of resistance to insulin, which controls blood sugar and regulates brain function. “Because insulin can penetrate the blood-brain barrier, the hormone may signal neurons to trigger reactions that disrupt learning and cause memory loss,” he said.

The study indicates that eating too much fructose could interfere with insulin’s ability to regulate how cells use and store sugar, which is necessary for processing thoughts and emotions. Ultimately, Gomez-Pinilla said, the study shows that a high-fructose diet harms the brain as well as the body.

“Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information,” Gomez-Pinilla said in the study. “But adding omega-3 fatty acids to your meals can help minimize the damage.”

Sugar continues to come under attack for its contribution to the obesity epidemic as well. New York City Mayor Michael Bloomberg proposed a far-reaching ban on the sale of large sodas and other “sugary drinks” last month. The new ban would affect businesses such as restaurants, movie theaters and street carts, but would not apply to supermarkets or convenience stores.

Bloomberg cited the rising number of obesity-related deaths in New York City, which will soon surpass smoking deaths. He highlighted several public health acts that were at first unpopular but are now embraced, such as those against public smoking and grading restaurants.