A significant study from the University of Sydney has revealed a connection between diets high in fat and sugar and impaired cognitive function.
The research team investigated the effects of high-fat, high-sugar (HFHS) diets, particularly those abundant in refined sugar and saturated fat, on first-person spatial navigation—an ability essential for learning and remembering pathways. This process is considered indicative of the health of the brain’s hippocampus, as detailed in their study published in the International Journal of Obesity.
Led by Dr. Dominic Tran from the Faculty of Science’s School of Psychology, the study found that HFHS diets negatively impact certain aspects of cognitive function, likely affecting the hippocampus, which is crucial for spatial navigation and memory formation.
“The good news is we believe this situation can be easily reversed,” Dr. Tran stated. “Dietary changes have the potential to improve hippocampal health, thereby enhancing our ability to navigate our surroundings, whether exploring a new city or learning a new route home.”
The research involved 55 university students aged 18 to 38, who completed questionnaires regarding their intake of sugary and fatty foods. Their working memory was tested through a number recall exercise, and their body mass index (BMI) was recorded.
Participants were then tasked with navigating a virtual reality maze to locate a treasure chest. This maze featured landmarks to assist with route memorization, with a consistent starting point and treasure location for each trial. If participants failed to find the treasure within four minutes, they were teleported to its location and given 10 seconds to familiarize themselves before proceeding to the next trial.
Those with lower fat and sugar consumption were able to locate the treasure with greater accuracy than those who indulged in such foods multiple times a week.
“After controlling for working memory and BMI, which we measured separately during the experiment, participants’ sugar and fat intake proved to be a reliable predictor of performance in the final, seventh test,” Dr. Tran noted.
He emphasized the importance of making healthy dietary choices to maintain brain function, stating, “We’ve long known that excess refined sugar and saturated fat increase the risks of obesity, metabolic and cardiovascular diseases, and certain cancers, while also accelerating age-related cognitive decline in middle-aged and older adults.”
“This research provides evidence that diet significantly affects brain health in early adulthood, a crucial period when cognitive function is usually still intact,” Dr. Tran concluded.