Reasons to avoid a high-fat diet are many. Here’s a new one — obesity in turn can actually rewire the brain and weaken memory and learning skills.
That’s the conclusion of a study out of American University in Washington DC, which found that subsisting off a diet of deep-fried, fatty and caloric foods was seen to kickstart a vicious cycle in lab mice.
The more high-fat foods they ate, the more impaired their blood-brain barrier became — a tight network of blood vessels which, when working efficiently, selectively screens what can get through and reach the hippocampus, the part of the brain responsible for learning and memory.
Published in the journal Physiology and Behaviour, the study put the rats through a series of cognitive tests, then split them into a high-fat and low-fat diet. Those that became obese from their high-calorie feed performed much more poorly than their skinnier counterparts when their learning and memory skills were tested again.
"What I think is happening is a vicious cycle of obesity and cognitive decline," said study lead author Terry Davidson, adding: "You eat high fat/high calorie diet and it causes you to overeat because this inhibitory system is progressively getting fouled up. And unfortunately, this inhibitory system is also for remembering things and suppressing other kinds of thought interference."
Since the hippocampus is also responsible for suppressing memories, the results of the study also suggest that a diet high in saturated fats and sugars impacts the brain’s ability to suppress unwanted thoughts and engage self-control, such as the desire for fatty foods.