Rapid Impact of Junk Food on Brain Memory Circuits Revealed by New Study

Recent research conducted by scientists at the UNC School of Medicine has uncovered how a diet high in junk food can swiftly impair the brain's memory functions. Published in the journal Neuron, the study demonstrates that consuming a high-fat, Western-style diet — common in foods like cheeseburgers and fries — can alter specific neurons in the hippocampus, a critical hub for memory processing. The researchers focused on a group of neurons called CCK interneurons, which become excessively active shortly after eating such fatty foods. This overactivity is linked to a decreased ability of the brain to effectively utilize glucose, the brain’s primary energy source. Interestingly, these changes in neuron activity occur within just a few days of high-fat diet consumption, even before any significant weight gain or metabolic conditions like diabetes appear. The study highlights the crucial role of protein PKM2 in energy regulation within brain cells, and how its disruption contributes to memory impairment.

The research team, led by Dr. Juan Song, found that the hyperactivity of CCK interneurons destabilizes hippocampal function, leading to early cognitive deficits. Remarkably, restoring glucose levels in the brain or implementing dietary interventions, such as intermittent fasting, was able to recalibrate neuron activity and improve memory in mice. These findings underscore the vulnerability of memory circuits to dietary influences and suggest that early nutritional interventions could help prevent long-term cognitive decline. The implications extend to understanding neurodegenerative diseases like Alzheimer’s, which are associated with diet-induced brain changes.

This rapid impact of high-fat foods on brain health emphasizes the importance of nutrition in maintaining cognitive function. It suggests that even short-term consumption of fatty junk foods can be detrimental, potentially increasing the risk of neurodegenerative disorders over time. Future research aims to explore whether these findings can be translated into human therapies, including dietary modifications and pharmacological approaches, to protect cognitive health amidst rising obesity and metabolic issues.

Source: https://medicalxpress.com/news/2025-09-junk-food-diet-quickly-disrupt.html