Scientists at the Ohio State University found that too much sugar or fat in our diets may alter gut bacteria, and thus impair cognitive functions and even cause memory loss on the long run.
Kathy Magnusson, lead author of the study and professor at the Ohio State University, explained that there is a clear link between the health of our gut bacteria and the brain. During their mouse studies, researchers learned that the mice with the most impairing effects to their cognitive skills where those on a high-sugar diets.
Scientists also learned that sugar does not only affect long-term memory but it can also negatively impact the short-term one. The findings are consistent with previous studies that had shown that changes in gut flora, or the microbiome, can result in behavior problems and a steep decline in brain functions.
The human microbiome is composed of more than 100 trillion bacteria that are highly sensitive to changes in the pH levels, which are easily altered by excess sugar consumption.
Prof Magnusson also argued that gut bacteria can create chemicals that act as neurotransmitters and can significantly influence the human brain. The bacteria can also stimulate or inhibit the immune response, stimulate sensory nerves and affect various other biological functions.
“We’re not sure just what messages are being sent, but we are tracking down the pathways and the effects,”
Prof Magnusson added.
During their research, scientists used various diets on laboratory mice and tested their cognitive and motor skills with various tests such as the water maze. After just one month, the mice that ate too much sugar or those on high-fat diets showed significant lower results than those kept on a healthy diet.
The research team noticed that the impaired mice found it really hard to adapt and adjust to new situations. This ability is called cognitive flexibility and humans also have it. Researchers said that we do not need the ability when driving the car on a well-known route.
But if a roadblock occurs, we need to find a new way to reach our destination and here the cognitive flexibility plays a huge role in our success. Prof. Magnusson underlined that the decline in brain function flexibility was especially “strong” in mice on high-sugar or high-fat diets.
A decline in humans could mean that they won’t be able to plan a new route while driving to their destination, and if they do manage to do it they will find it really hard to remember it the next day.
Additionally, researchers said that the influence of sugar and fats on brain functions was even more dramatic in older mice.
Image Source: UCSF