July 22, 2009

Fructose impairs spatial memory in rats

Diets high in fructose -- a type of sugar found in processed foods and beverages -- impaired the spatial memory of adult rats, U.S. researchers said.

Amy Ross, a graduate student in the lab of Marise Parent, an associate professor at Georgia State University, fed a group of rats a diet where fructose represented 60 percent of calories ingested during the day.

Ross placed the rats in a pool of water to test their ability to learn to find a submerged platform, which allowed them to get out of the water. She returned the rats to the pool two days later with no platform present to see if the rats could remember to swim to the platform's location.

What we discovered is that the fructose diet doesn't affect their ability to learn, Parent said. But they can't seem to remember as well where the platform was when you take it away. They swam more randomly than rats fed a control diet.

Fructose, unlike another sugar, glucose, is processed almost solely by the liver, and produces an excessive amount of triglycerides -- fat which get into the bloodstream, Ross said.

The findings are scheduled to be presented at the Society for Neuroscience meeting in Chicago in the fall.