A diet high in ultra-processed foods (UPFs) can negatively impact the brain's ability to focus and increases the risk of developing dementia, even in people who otherwise eat healthfully, a recent analysis suggests. The researchers considered UPFs as everyday products like soft drinks, packaged salty snacks, and ready-made meals – essentially anything that’s not fresh whole foods.

For the study, researchers examined the diets and cognitive health of more than 2,100 Australian dementia-free adults who were middle-aged and older. They found that for every 10% increase in UPFs consumed, there was a distinct and measurable drop in attention span. This translated to consistently lower scores on standardized cognitive tests measuring visual attention and processing speed.

Overall, study participants consumed roughly 41% of their daily energy from UPFs, closely mirroring the national Australian average of 42%. Importantly, the negative effects occurred regardless of overall diet quality, even among people following a healthy Mediterranean diet, suggesting that the degree of food processing itself plays a key role.

"Food ultra-processing often destroys the natural structure of food and introduces potentially harmful substances like artificial additives or processing chemicals," explained lead author Barbara Cardoso, Monash University, Australia. "These additives suggest the link between diet and cognitive function extends beyond just missing out on foods known as healthy."

Eating more UPFs was also linked to an increase in dementia risk factors, including high blood pressure and obesity.

To download the study, published in Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, click here