A study at Oregon State University indicates that both a high-fat and a high-sugar diet, compared to a normal diet, cause changes in gut bacteria that appear related to a significant loss of “cognitive flexibility”.

This effect was most serious on the high-sugar diet, which also showed an impairment of early learning for both long-term and short-term memory.

The findings are consistent with some other studies about the impact of fat and sugar on cognitive function and behavior, and suggest that some of these problems may be linked to alteration of the microbiome – a complex mixture in the digestive system of about 100 trillion microorganisms.

The research was done with laboratory mice that consumed different diets and then faced a variety of tests, such as water maze testing, to monitor changes in their mental and physical function, and associated impacts on various types of bacteria. The findings were published in the journal Neuroscience.

“Bacteria can release compounds that act as neurotransmitters, stimulate sensory nerves or the immune system, and affect a wide range of biological functions,” said Kathy Magnusson, a professor in the OSU College of Veterinary Medicine and principal investigator with the Linus Pauling Institute.

In this research, after just four weeks on a high-fat or a high-sugar diet, the performance of mice on various tests of mental and physical function began to drop, compared to animals on a normal diet. One of the most pronounced changes was in what researchers call cognitive flexibility.

This study was done with young animals, Magnusson said, which ordinarily would have a healthier biological system that’s better able to resist pathological influences from their microbiota. The findings might be even more pronounced with older animals or humans with compromised intestinal systems, she said.

What’s often referred to as the “Western diet,” or foods that are high in fat, sugars and simple carbohydrates, has been linked to a range of chronic illnesses in the United States, including the obesity epidemic and an increased incidence of Alzheimer’s disease.

If you are interesting in discussing ways to improve your diet, health, or hormone levels Dr. Russo at Carolina HealthSpan Institute Lake Norman, is Fellowship trained in Integrative Medicine. Please call for your personal consultation 704 727-5360