It’s possible. In fact, researchers have demonstrated exactly how bad a junk-food diet can be for the brain. They studied rats instead of people, but it’s not a huge leap to see how the results apply to all of us.
Scientists from the University of California, Los Angeles, fed some of the rodents a healthy diet and others a high-fat, high-sugar diet. Some of the rats were allowed exercise, some were not. Then they all were tested in a swimming pool (rat-size, of course) to see how well they remembered the location of a platform.
The junk-food-only rats who didn’t exercise had virtually no memory and swam randomly around the pool. They were found to have a reduced level of the chemical known as brain-derived neurotrophic factor, or BDNF, the “Miracle-Gro” brain chemical that stimulates the growth and proliferation of brain cells and is critical to long-term memory.
The junk-food rats who exercised performed somewhat better, but the rats that ate well and exercised did the best of all.
One problem with sweets and sugary drinks is their effect on glucose. Most of them trigger blood-sugar swings that are toxic to brain cells. And, of course, they can lead to weight gain and contribute to the development of diabetes, stroke, and cardiovascular disease-all bad for the brain.