Junk Food Can Scramble Your Memory in Just 4 Days; Tips to Protect Brain Health

Eating

junk food in all meals – even for four days can result in disruption of memory and speed up dementia, a new study has revealed. A new study published in Neuron reveals that a diet of foods like pizza, burgers, fries, and chips disrupts your brain’s “memory hub” - the hippocampus. Researchers said that a high-calorie and high-fat diet messes with your brain’s delicate balance of neurons, which causes brain fog, memory lapses, and slower thinking almost immediately.

What is the hippocampus?

Your hippocampus is a small part of your brain that has a big job – which is helping with your learning and memory. It helps convert short-term memories into long-term ones by organizing, storing, and retrieving memories within your brain. Your hippocampus also helps you learn more about your environment so that you become aware of what is around you, as well as remembering what words to say. And so, doctors say what you put on your plate can directly affect how well your brain remembers and processes information.

How does junk food affect your hippocampus?

Scientists conducted tests on mice, which revealed that after just four days of a high-fat diet, their hippocampal cells - known as CCK interneurons became overactive and unable to process glucose properly. That directly resulted in disruption to memory pathways. Experts believe it helps explain how a poor diet contributes to cognitive decline. Encouragingly, the researchers have found that restoring normal access to glucose—either through fasting or by changing diet— can calm the neurons and reverse memory problems. “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,” UNC School of Medicine’s Juan Song, PhD, principal investigator, professor of pharmacology, said. “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,” he added. Even though the study was conducted on mice, experts believe that human studies show similar effects. Those who eat too much of processed or high-fat foods report more brain fog, forgetfulness, and slower reaction times - even after short periods. “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,” said Song. “In the long run, such strategies could help reduce the growing burden of dementia and Alzheimer’s linked to metabolic disorders, offering more holistic care that addresses both body and brain.”

How to take care of your cognitive health?

To minimise the risk of brain fog or memory issues, you can take the following steps:

• Prioritise a healthy and balanced diet
• Get quality sleep
• Stay physically active through regular exercise to improve blood flow and reduce cognitive decline.
• Challenge your mind by learning new skills and engaging in puzzles.
• Manage stress
• Maintain social connections to support overall mental well-being.
• Quit smoking and drinking alcohol.
• Get regular medical check-ups to manage conditions like diabetes and high blood pressure that impact brain health.