4 Days of Junk Food Does This to Your Brain

Heady Stuff: Junk food isn’t just bad for our waistlines. According to a new study, it’s also bad for our brains. Within four days of eating high-fat junk food (like fast food or ultra-processed snacks), some neurons in the brain become overactive, disrupting how memories are processed in the hippocampus.

The Study: Researchers at the University of North Carolina School of Medicine identified certain neurons become abnormally active after we gorge on burgers, fries, or other high-fat junk food. When they become hyperactive, the brain has trouble getting the glucose it needs for fuel. This upsets memory processing. Here’s the good news: Researchers found replacing missing glucose fixed the memory problems, as did a brief period of intermittent fasting after eating high-fat foods.

The Takeaway: Obesity and high-fat diets are well-known risk factors for cognitive decline and the development of dementia and Alzheimer’s disease. This study underscores the connection between diet and brain health. The findings also show potential for new therapies and interventions to protect memory.

Keep in Mind: The research was done on mice that were put on Western-style high-fat diets, not humans. But it’s certainly well-established that meals or snacks high in saturated fat should be “occasionally” foods, not everyday ones.