Here’s how a sweet diet can cause memory loss later in life:

New studies show that drinking sweet drinks early in life can lead to memory loss in adulthood. The results of this study were published in the journal “Translational Psychiatry”. This is the first study to show how specific changes to the intestinal flora (bacteria and other microbes that grow in the stomach and intestines) alter the function of specific areas of the brain.

According to the US Centers for Disease Control and Prevention, sugar-sweetened beverages are a major source of sugar added to the American diet. Almost two-thirds of young people in the United States drink at least one sweet drink daily.

Neuroscientist Scott Kanoski, an associate professor of biological sciences at the University of Southern California, USC Dornife, has been studying the relationship between diet and brain function for years. His study showed that ingestion of sugar-rich beverages impaired rat memory function, and that the same beverage alters the gut microbiota.

In the current study, researchers at Kanoski and UCLA and the University of Georgia at Athens sought to find out if there was a direct link between microbiome changes and memory function.

Scientists have given adolescent mice free access to sugar-sweetened drinks similar to those humans drink.

When the rats grew into adults after about a month, researchers used two different methods to test their memory. One method tested memory associated with an area of ​​the brain called the hippocampus. Another method tested memory function controlled by an area called the peri-nasal cortex.

Researchers have found that rats that drank high levels of sweet drinks had more difficulty remembering to use the hippocampus than rats that drank only water. Sugar consumption did not affect the memory created by the peri-nasal cortex.

“Early sugar consumption seems to selectively impair hippocampal learning and memory,” said the lead author of the study, an assistant professor at the UGA Family and Consumer Sciences University and a former postdoc at USC Dornife. Emily Noble says.

Scientists then checked the rat’s gut microbiota and found the difference between drinking a sweet drink and drinking water. Sugar drinkers were predominantly populations of two specific species of gut microbiota, Parabacteroides distasonis and Parabacteroides johnsonii.

Next, researchers asked if Parabacteroides could affect rat memory function without the help of sugar. They transplanted laboratory-grown Parabacteroides into the intestines of adolescent mice that drank only water. Bacterial-fed rats showed hippocampal memory impairment when they became adults, much like sugar-drinking rats.

Scientists also found that, unlike sugar-drinking rats, transplanted rats also showed memory loss in the peri-nasal cortex. This difference provides further evidence that diet-related changes in brain function may actually be rooted in changes in the gut microbiota.

In a previous study, the entire gut flora was transplanted from one group of animals to another, resulting in similar changes in brain function. However, this study is one of the first studies to do this with only two specific species.

“It was surprising to us that we were able to essentially recreate the memory deficits associated with sugar consumption by simply concentrating a single bacterial population in the gut rather than transferring the entire microbiome.” Survey.

Finally, scientists examined hippocampal genetic activity, comparing rats that drank sugar-containing drinks with rats that drank only water, and rats that drank water and rats transplanted with parabacteroides. ..

In fact, genetic activity was altered in both rats fed sugar-containing beverages and rats transplanted with parabacteroides. Affected genes control how nerve cells send electrical signals to other nerve cells and how they internally send molecular signals.

The results of this study confirm a direct molecular-level association between gut flora and brain function.

In future studies, Kanoski and researchers will find that changes in habits, such as eating a healthier diet and increasing exercise, can harm memory caused by increased sugar consumption early in life. I want to determine if it can be reversed.