High Fat & Sugar in Diet Could Decrease Cognitive Function! How Is This Possible?

Eating a diet that is high in fat or sugar can do more than just contribute to unhealthy weight; a new study has shown that such diets could also decrease cognitive function.

Scientists from Oregon State University published a study in the journal Neuroscience that shows diets high in fat and sugar can alter gut bacteria that could reduce cognitive flexibility — the ability to "adapt and adjust in changing situations," according to the researchers, as per Eureka Alert.

Out of the two, a high-sugar diet is much more damaging because it is linked to poorer short-term and long-term memory.

"We've known for a while that too much fat and sugar are not good for you," said Dr Katy Magnusson, lead author and scientist at the University. "This work suggests that fat and sugar are altering your healthy bacterial systems, and that's one of the reasons those foods aren't good for you. It's not just the food that could be influencing your brain, but an interaction between the food and microbial changes."

She added that the bacteria in the gut can communicate with the brain.

"Bacteria can release compounds that act as neurotransmitters, stimulate sensory nerves or the immune system, and affect a wide range of biological functions," Dr. Magnusson explained. "We're not sure just what messages are being sent, but we are tracking down the pathways and the effects."

For the research, the scientists fed mice with high-fat diet, high-sugar diet, or normal diet for four weeks. They found that mice models that were fed with excessive fat or sugar performed poorly on tests compared to normal diet mice.

The sugar-fed mice also had low performance of memory tests, according to Huffington Post. The scientists were able to surmise from the study on mice that high-fat or high-sugar diets can strongly affect cognitive functioning.

To profoundly explain what cognitive flexibility is, Dr. Magnusson said that it is like driving home using a familiar route but on situations where it is closed, it is naturally assumed to find a different pathway.

Those with functioning cognitive flexibility would be able to think of a new alternative route, but those with impaired cognitive flexibility will react negatively by the change and would take longer in getting home.

According to Magnusson and colleagues, their study is consistent with other previous studies on the effects of high-fat and high sugar diets which are often referred to as the "Western diet." This type of diet has been associated with the obesity epidemic and increased risks of Alzheimer's disease.