We all know that a high-sugar diet can lead to weight gain, insulin resistance, hyperactivity in children and a host of other health problems. And, according to a recent study, the sweet stuff might affect how you think, as well. That's the bad news, but there's good news too: a diet rich in omega-3 fatty acids may help to mitigate sugar's effect on the brain.
Researchers at UCLA's David Geffen School of Medicine used rats to explore how a high-fructose diet affects basic cognitive abilities like memory, learning and problem-solving. "Our findings illustrate that what you eat affects how you think," said professor of neurosurgery Fernando Gomez-Pinilla at the David Geffen School of Medicine at UCLA in a statement. "Eating a high-fructose diet over the long term alters your brain's ability to learn and remember information." Interestingly, the researchers found that eating omega-3 fatty acids could help to mitigate the sugar-associated damage.
Gomez-Pinilla and his colleague, Rahul Agrawal, looked specifically at high-fructose corn syrup, a common sweetener in processed foods like sodas, packaged cookies, condiments, sauces and even baby formula. The average American consumes more than 40 pounds of high-fructose corn syrup each year.
The two researchers devised an experiment in which they trained a group of rats on a complicated maze twice a day for five days. After that, they split the rats into two groups. They gave both groups of rats a high-fructose corn syrup solution in place of water, but one of the groups was additionally given flaxseed oil and docosahexaenoic acid (known more commonly as DHA) -- two high-quality sources of omega-3 fatty acids, which are known to protect against neural damage.
After six weeks of the sugary diet, the researchers reintroduced the maze. They found that the sugar-only group had a much harder time recalling the maze and were slower in their problem solving. The sugar-and-omega-3 group fared better. Gomez-Pinilla theorizes that the high-sugar diet is bad for the brain for the same reason it's harmful to the body: too much fructose disrupts production of the hormone insulin, which is used by the body to regulate blood sugar. Steady blood sugar levels are essential to provide energy for things like walking and running -- but also for recalling and problem-solving.
"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 a press release.
The study, published in this week's issue of the Journal of Physiology is the first to look at how sugar affects the brain's function.