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Eating too much sugar can make you dull: Scientists- 16-May-2012
In experiments on mice, researchers at the University of California in Los Angeles found that eating high-fructose diets -- such as cakes, cookies, jams, jellies, crackers and carbonated soft drinks -- for as little as six weeks can make one stupid.
But, a diet high in omega-3 fatty acids can counteract this IQ loss, the researchers suggested.
"Our findings illustrate that what you eat affects how you think," study researcher Fernando Gomez-Pinilla said.
"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 minimise the damage," Gomez-Pinilla was quoted as saying by LiveScience.
The study, published in Journal of Physiology, was done on rats, but the researchers believe their brain chemistry is similar enough to humans to extend the findings.
For the study, the researchers 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, applesauce and baby food.
Before starting the experiment, the rats were taught to navigate their way through a maze using visual landmarks to remember the way.
After six weeks of their new diet, the researchers tested the rats' recall of the maze route. "The second group of rats navigated the maze much faster than the rats that did not receive omega-3 fatty acids," Gomez-Pinilla said.
"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."
The rats fed only high fructose corn syrup developed insulin resistance, which the researchers think may be what's hurting the brain cells.
Insulin resistance due to the constant flow of fructose may have changed how cells use and store sugar and use it as the energy required for processing thoughts and emotions. (sugar is the only fuel that brain cells know how to use.) If the brain cells can't use insulin correctly, it could impact how they work.
"Insulin is important for controlling blood sugar, but it may play a different role in the brain, where insulin appears to disturb memory and learning," Gomez-Pinilla said.
"Our study shows that a high-fructose diet harms the brain as well as the body. This is something new."
The study also suggests that omega-3 fatty acids may help protect or heal the brain from this damage, he said, though the researchers aren't sure how either of these effects happen at the molecular level in the brain.
The researchers recommended taking one gram of omega-3 fatty acids per day.
