A new University of California – Los Angeles (UCLA) rat study is the first to show how a diet steadily high in fructose (fruit sugar) slows the brain, hampering memory and learning – and how omega-3 fatty acids can counteract the disruption.
“Our findings illustrate that what you eat affects how you think,” said Fernando Gomez-Pinilla, professor of neurosurgery at the UClA’s David Geffen School of Medicine at UCLA, the Journal of Physiology reports.
“Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information. But ¬adding omega-3 fatty acids to your meals can help minimize the damage,” adds Gomez-Pinilla, according to an UCLA statement.
While earlier research has revealed how fructose harms the body through its role in diabetes, obesity and fatty liver, this study is the first to uncover how the sweetener influences the brain.
The UCLA team zeroed in on high-fructose corn syrup, an inexpensive liquid six times sweeter than cane sugar, that is commonly added to processed foods, including soft drinks, condiments, apple sauce and baby food.
Gomez-Pinilla and study co-author Rahul Agrawal, studied two groups of rats that each consumed a fructose solution as drinking water for six weeks.
The second group also received omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), which protects against damage to the synapses – the junctions between brain cells that enable memory and learning.
“DHA is essential for synaptic function – brain cells’ ability to transmit signals to one another,” Gomez-Pinilla said. “This is the mechanism that makes learning and memory possible. Our bodies can’t produce enough DHA, so it must be supplemented through our diet.”
Six weeks later, researchers tested the rats’ ability to recall the route and escape the maze. What they saw surprised them. “The second group of rats navigated the maze much faster than the rats that did not receive omega-3 fatty acids,” Gomez-Pinilla said.
“The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity. Their brain cells had trouble signalling each other, disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier,” he concludes.