"You can't necessarily salad your way out" of this snacking habit, one doctor noted. The study, published in the journal Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, found that eating more ultra-processed foods was associated with declines in attention and mental processing speed. Notably, the association held up even among people who otherwise followed a healthy diet ― a finding that experts say adds an important wrinkle to how we think about nutrition and brain health.