Researchers discovered that a few days of eating high-fat junk can disrupt brain cells involved in memory
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A high-fat diet, similar to typical saturated fatrich junk food, causes certain brain cells in the hippocampusto become overly active after only a few days.
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This overactivity stems from reduced glucose (sugar) availability in the brain, and is linked with impaired memory performance.
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Interventions like restoring glucose levels or dietary changes (for example, intermittent fasting) were shown in mice to reverse these negative effects and improve memory.
We all know diet matters for physical health, but a new study shows the impact of junk food may catch up with your brain surprisingly fast.
Research from UNC School of Medicine, published recently in Neuron, reveals that eating foods high in saturated fat (think fries, cheeseburgers) can alter memory circuitry very quickly even before things like weight gain or diabetes set in.
The investigation zeroes in on the brains hippocampus, the area responsible for many aspects of memory, and describes how specific brain cells respond when the diet is poor.
We knew that diet and metabolism could affect brain health, but we didnt 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, researcher Juan Song, PhD, said in a news release.
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.
The study
The scientists used mice as their model. They fed some of these mice whats called a high-fat diet (HFD) meant to mimic the saturated-fat heavy junk food many people eat.
They then tracked what happened in the hippocampus, especially focusing on a type of neuron called a CCK (cholecystokinin) interneuron. These neurons are important for shaping how memories are formed and maintained. They also monitored how the brain was using glucose basically, how well brain cells were getting fuel.
Behavioral tests were conducted to see how well mice remembered things after being on the high-fat diet. The researchers also manipulated glucose levels and tried dietary-change interventions (including periods of fasting) to see if the impairments could be reversed.
The study design allowed comparison among mice that stayed on the high-fat diet, those whose glucose was restored, and those who underwent diet modifications.
The results
Within just four days on the high-fat diet, the CCK interneurons in the hippocampus showed abnormally high levels of activity a sign things are going off-balance.
This overactivity seemed connected to lower glucose availability in the brain, meaning the brain wasnt getting enough fuel. As a result, memory performance worsened in the mice, even though other markers of illness (like weight gain or diabetes) werent yet evident.
Encouragingly, the researchers found that restoring glucose availability could calm down those overactive neurons and improve memory. Also, dietary strategies (for example, introducing intermittent fasting after the high-fat diet) helped to normalize neuron activity and rescued memory performance in the animals.
The power of early intervention
The take-away?
It appears that the brains memory circuits are more sensitive to diet than many people assume and even shortterm indulgence in high-fat junk food can trigger measurable changes. But, on the positive side, early interventions might reverse or prevent harm before it becomes.
This work highlights how what we eat can rapidly affect brain health and how early interventions, whether through fasting or medicine, could protect memory and lower the risk of long-term cognitive problems linked to obesity and metabolic disorders, Dr. Song said.
In the long run, such strategies could help reduce the growing burden of dementia and Alzheimers linked to metabolic disorders, offering more holistic care that addresses both body and brain.
Posted: 2025-09-18 18:04:04
