This diet could be messing with your memory — even after just a few days

Here’s some food for thought.

The brain requires a steady supply of nutrients, antioxidants and healthy fats to perform well. Foods like fatty fish, fruits, vegetables, whole grains, nuts and seeds have been shown to support brain structure, function and memory.

On the flip side, constant consumption of high-fat junk food can harm the brain’s ability to process memory, potentially increasing the risk of neurodegenerative diseases like dementia and Alzheimer’s, a new study from the UNC School of Medicine confirms.

Eating ultra-processed foods like cheeseburgers, fries and ice cream over just a few days can send a special group of brain cells called CCK interneurons into overdrive by interfering with the brain’s sugar metabolism, the study found.

This hyperactivity impairs the processing of new memories in the brain’s hippocampus.

“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,” said Juan Song, principal investigator and professor of pharmacology.

“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.”

Obesity, a chronic, progressive disease, is known to harm brain health by reducing blood flow, shrinking brain volume and triggering neuroinflammation.

For the study, Song’s team had mice eat a high-fat diet resembling the Western diet.

Within just four days, well before obesity can take hold, the researchers noticed that the CCK interneurons in the mice had become abnormally active.

The good news is that intermittent fasting — not eating for a certain period of time — was able to counteract the effects of the high-fat diet by calming down the CCK interneurons and improving memory function. Medicine may also be an effective tool.

During a fast, the body shifts from relying on sugar for energy to burning stored fat.

Restoring the availability of sugar is key to normalizing CCK interneuron activity, the UNC researchers found, as is reducing the activity or expression of the protein pyruvate kinase M2.

PKM2 is an enzyme that regulates the final step of the metabolic process of converting sugar into energy. Drugs like metformin and rapamycin, certain herbal compounds and calorie restriction have been shown to affect PKM2.

The findings were published last week in the journal Neuron.

The team plans to further explore how high-fat diets may affect Alzheimer’s, the most common type of dementia.

The researchers will also investigate diets that promote brain glucose regulation to see if they offer protective benefits.