If you can’t get through the day without a can of fizz, two sugars in your tea or a junk food binge, you are not only ruining your waistline - you could be dumbing down your brain, too.
A team of scientists from the University of California discovered that the brains of people who eat large amounts of sugar for as little as six weeks, could experience a sharp decline in learning and memory ability as a result.
Researchers came to this conclusion after giving lab rats a high-fructose corn syrup solution in place of drinking water for six weeks.
Fructose corn syrup is commonly found in fizzy drinks and processed junk foods and is an artificial type of fructose found naturally in fruit.
Prior to the study, the rats were fed a standard diet and trained to complete complex mazes twice a day for five days. After six weeks of being fed the high-fructose solution, researchers noticed a significant reduction in the rats’ ability to navigate through the maze.
"Our findings illustrate that what you eat affects how you think," lead researcher Fernando Gomez-Pinilla said in a statement. "Eating a high-fructose diet over the long term alters your brain's ability to learn and remember information.”
Gomez-Pinilla believes that insulin - the hormone that is central to regulating carbohydrates and fat metabolism in the body - is key to these findings.
"Insulin is important in the body for controlling blood sugar, but it may play a different role in the brain, where insulin appears to disturb memory and learning," explains Gomez-Pinilla.
"Our study shows that a high-fructose diet harms the brain as well as the body. This is something new."
In contrast, another group of lab rats were fed a diet high in omega-3 fatty acids and docosahexaenoic acid (DHA), which help protect against damage to the brain’s synapses (the structure that allows neurons to communicate with the brain).
Researchers discovered these rats navigated their way through the mazes much faster than those on a high-fructose diet.
"The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity. 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,” explained Gomez-Pinilla.
In short, researchers believe that if you have a high-sugar diet, derived mainly from processed food – the damage can be reversed if you swap fructose with foods high in omega-3.
"Our findings suggest that consuming DHA regularly protects the brain against fructose's harmful effects," said Gomez-Pinilla. "It's like saving money in the bank. You want to build a reserve for your brain to tap when it requires extra fuel to fight off future diseases."
Foods high in omega-3 fatty acids include salmon, walnuts, sardines, tuna, tofu and soybeans.
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