ESPScientists discovered that high-fat junk food disrupts memory circuits in the brain almost immediately. Within just four days, neurons in the hippocampus became overactive, impairing memory. Restoring glucose calmed the neurons, showing that interventions like fasting or dietary shifts can restore brain health. This could help prevent obesity-related dementia and Alzheimer’s.
Led by UNC School of Medicine's Juan Song, PhD, principal investigator, professor of pharmacology, and Taylor Landry, PhD, first author, Department of Pharmacology, researchers found that a special group of brain cells in the hippocampus, called CCK interneurons, become overly active after eating a high-fat diet (HFD), due to an impaired ability of the brain to receive glucose (sugar). This overactivity disrupts how the hippocampus processes memory, even after just a few days of high fat diet. This type of diet resembles typical Western-style junk food rich in saturated fat -- like cheeseburgers and fries. The discovery also showed that a protein called PKM2, which controls how brain cells use energy, plays a key role in this problem.
"We knew that diet and metabolism could affect brain health, but we didn't expect to find such a specific and vulnerable group of brain cells, CCK interneurons in the hippocampus, that were directly disrupted by short-term high-fat diet exposure," Song said, who is a member of the UNC Neuroscience Center. "What surprised us most was how quickly these cells changed their activity in response to reduced glucose availability, and how this shift alone was enough to impair memory."
Know more: https://www.sciencedaily.com/releases/2025/09/250927031249.htm
