The Opposite of Brain Food? New study suggests that diets high in fat and sugar can lead to cognitive impairments
Diets high in sugar and fat have never exactly been the best choice for our physical health. But a new study conducted by Dr. Kathy Magnusson of the Linus Pauling Institute at Oregon State University suggests that they’re a bad choice for our mental health as well.
“It’s increasingly clear that our gut bacteria, or microbiota, can communicate with the human brain,” Magnusson said in an interview. And according to her lab’s latest study, when it comes to fat and sugar that communication is anything but friendly.
In her experiment, Dr. Magnusson gave newborn lab mice a variety of different diets for four weeks and then put them through a battery of intelligence tests, including navigating a water maze. Mice on high fat diets and high sucrose diets were reported to have far less cognitive flexibility than their healthy eating brethren. “Cognitive Flexibility,” in case you’re curious, is a term that refers to our ability to adapt to new or changing situations.
“Think about driving home on a route that’s very familiar to you,” Magnusson said when asked to explain the term “something you’re used to doing. Then one day that road is closed and you suddenly have to find a new way home.” A person with high cognitive flexibility would rise to the occasion, easily finding the second best route or maybe even a better one. On the other hand – a person with low cognitive flexibility would have a much harder time adapting to the situation and finding another way back home.
“We’ve known for a while that too much fat and sugar are not good for you,” Magnusson said. “This work suggests that fat and sugar are altering your healthy bacterial systems… It’s not just the food that could be influencing your brain, but an interaction between the food and microbial changes.”
Magnusson, and the broader scientific community, have dubbed these high-fat high-sugar diets as ‘western diets,’ due to their ubiquity in the western world. These “western diets” have been linked to or are theorized to be the cause of dozens of health problems from obesity and diabetes to Alzheimer’s. It’s clear that if we want to make any progress stopping the progression of these diseases, we’re going to have to take matters into our own hands, and that may mean changing our diets and our culture. Otherwise, we’re just eating our health – and our cognitive flexibility- away.