University of California Los Angeles (UCLA) Researchers fed two groups of rats a solution containing high-fructose corn syrup — a common ingredient in processed foods — as drinking water for six weeks.
One group of rats was supplemented with brain-boosting omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), while the other group was not. Before the sugar drinks began, the rats were enrolled in a five-day training session in a complicated maze. The rats were placed back in the maze six weeks later on the sweet solution to see how they fared.
“The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity,” said Fernando Gomez-Pinilla, a professor of neurosurgery at the David Geffen School of Medicine at UCLA.
“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.”
A closer look at the rat brains revealed that those who were not fed DHA supplements had also developed signs of resistance to insulin, a hormone that 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,” Gomez-Pinilla said.
In other words, 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.