Feeling a little brain-dead these days? That may be more true than you know.
Most of us accept brain fog as just a part of our hectic modern-day lifestyles. But before you chalk up your inability to focus and memory problems to too much internet and too little sleep, take a look at your diet. Eating a high-fat diet can actually cause your brain to eat itself, according to a new study published in the journal Brain, Behavior, and Immunity. The scientists found that mice eating a high-fat diet—defined in this study as 60 percent of calories from fat—led to a response that turned their immune system against their little rodent brains.
Researchers looked at two groups of mice: The first group was put on a healthy diet of food containing 10 percent fat while the second group was put on an equally healthy diet, but one with food containing 60 percent fat. At eight weeks, the high-fat group had become obese but both groups were similarly healthy in both brain and body. But by twelve weeks, the scientists began to see cognitive problems in the high-fat group. Brain scans showed that their microglia—the cells in the brain responsible for getting rid of garbage—had become "lazy". (A High-Fat Diet Can Torpedo Your Metabolism too.)
"Normally in the brain, microglia are constantly moving around. They are always moving around their little fingers and processes. What happens in obesity is they stop moving," explained Alexis M. Stranahan, Ph.D., a neuroscientist in the Department of Neuroscience and Regenerative Medicine at the Medical College of Georgia and lead author of the study. "[Dietary] fat dramatically alters their dynamic."
It gets worse. Not only do the microglia stop doing their job, but they start feasting on the nearest thing: brainzzzz. "And when microglia start eating synapses, the mice don't learn as effectively," Stranahan added.
The good news: There is a cure for this zombie disease, and it doesn't involve a shotgun. When the mice were returned to a low-fat diet, they were able to regrow the synaptic connections they'd lost and their memories and attention spans improved. And it worked whether or not the fat mice lost weight. Simply lowering the fat content of their diets was enough to improve cognitive function.
Whether or not this phenomenon works the same way in human brains remains to be seen, but in the meantime, there are plenty of other benefits from removing unhealthy fats from your diet. No need to go overboard as people, and women especially, need fat to be healthy. But cutting out fatty junk food can only help you. And if it keeps brain-eating zombies away? Even better! (Find out if Your High-Fat Diet Is Messing with Your Mood.)