High-Fat and High-Sugar Diets Deteriorate Cognitive Function

Recent research conducted by the University of Sydney has established a connection between diets rich in fats and sugars and impaired cognitive abilities. While the physical consequences of consuming high-fat, high-sugar (HFHS) foods such as obesity, heart disease, and cancer are well-documented, this new study emphasizes their negative impact on brain health, specifically cognitive functions related to spatial navigation.

Published in the International Journal of Obesity, the research is pioneering in its approach to examining how HFHS diets—particularly those high in refined sugar and saturated fats—affect memory and spatial learning in humans. The study focused on the hippocampus, a critical brain region responsible for navigation and memory formation.

Led by Dr. Dominic Tran from the School of Psychology, the study involved 55 university students aged 18 to 38. Participants completed questionnaires detailing their dietary habits, especially their intake of sugary and fatty foods. They also underwent cognitive tests, including a virtual reality maze task designed to assess spatial navigation skills.

In the experiment, participants navigated a virtual maze to locate a treasure chest six times, with landmarks aiding their memory of the path. Their performance was evaluated based on their speed and accuracy. A final test asked participants to locate the previous position of the treasure, relying solely on memory. Results showed that individuals with lower consumption of fats and sugars consistently performed better in remembering the treasure's location.

Importantly, after accounting for factors like working memory and body mass index (BMI), dietary sugar and fat intake remained strong predictors of spatial navigation performance. This suggests that unhealthy eating patterns can impair the hippocampus, potentially leading to early cognitive decline.

Dr. Tran highlighted that these effects are likely reversible. Improving dietary choices could enhance hippocampal health and, consequently, spatial and memory functions—skills important for everyday navigation and learning.

Although the study's sample was not fully representative of the general population, findings are significant. The researchers believe that if the study included a broader demographic, the impact of HFHS diets on cognitive abilities might be even more pronounced.

This research underscores the importance of healthy eating habits not only for physical health but also for maintaining optimal brain function from early adulthood. Making mindful dietary choices may help prevent age-related cognitive decline and support overall mental health.

Source: https://medicalxpress.com/news/2025-04-high-fat-sugar-diets-impact.html