18/09/2025
🧠 Fast food doesn’t just affect your waistline — it can rewire your brain’s in less than a week.
Just four days of junk food may be enough to start rewiring the brain’s memory circuits, according to a new study from the University of North Carolina School of Medicine.
Researchers found that high-fat diets mimicking typical Western fast foods disrupt neurons in the hippocampus—the brain’s memory hub—by interfering with glucose use.
This disruption causes a specific set of neurons, called CCK interneurons, to become hyperactive, impairing memory function. The findings, published in Neuron, suggest that unhealthy eating habits can affect brain health almost immediately, long before weight gain or diabetes appear.
The good news is that the damage may be reversible. The team discovered that restoring glucose availability—either through dietary changes, fasting, or pharmacological interventions—calmed overactive neurons and improved memory performance in mice. Lead researcher Juan Song, PhD, noted that the rapid effect of diet on brain cells was unexpected but underscores how strongly nutrition influences cognitive health. These insights could pave the way for new strategies to protect against dementia and Alzheimer’s, especially in people at risk due to obesity and metabolic disorders.
Source: Landry, T., Perrault, L., Melville, D., et al. (2025, September 11). Targeting glucose-inhibited hippocampal CCK interneurons prevents cognitive impairment in diet-induced obesity. Neuron.