Most people are aware that too much sugar and fat are bad for you. Recent studies have identified links between fat and sugar on what is termed “cognitive flexibility,” which is our ability to adapt and adjust to changing situations. Even more intriguing is that this loss of cognitive flexibility seems to be linked to alterations in the gut microbiome. The gut microbiome refers to about 100 trillion microorganisms that inhabit our gastrointestinal tract. A diet high in sugar and fat changes the composition of the normal bacteria that comprise the gastrointestinal tract. The microbiome somehow communicates with the brain by releasing certain compounds that can act as neurotransmitters, stimulate the immune system, and affect a wide range of biological functions.

It may not be just the food in and of itself that is bad for us, but the interaction between the food and the bacteria in the gut. A wide range of chronic illnesses in the United States, from obesity to the increased incidence of Alzheimer’s disease could possibly be the consequences of the typical western diet, which is high in fat, sugars and simple carbohydrates. This adds to the mounting evidence that a healthy diet and a healthy gut can prevent cognitive problems that increase with age.