A new Australian study linked higher intake of ultra-processed foods to lower attention and focus scores.
Researchers found the effect appeared even in people who otherwise followed healthy eating patterns.
The study adds to growing concerns about how food processing itself may affect brain health.
People often think of ultra-processed foods (UPFs) as a problem mainly because they contain extra sugar, salt, or unhealthy fats. But new research suggests the issue may go deeper than nutrition labels alone.
A study led by researchers at Monash University found that diets higher in ultra-processed foods were associated with poorer attention and focus, even among people who generally ate healthy diets.
“To put our findings in perspective, a 10% increase in UPFs is roughly equivalent to adding a standard packet of chips to your daily diet,” researcher Dr. Barbara Cardoso said in a news release.
“For every 10% increase in ultra-processed food a person consumed, we saw a distinct and measurable drop in a person’s ability to focus. In clinical terms, this translated to consistently lower scores on standardized cognitive tests measuring visual attention and processing speed.”
The study
The findings were published in the journal Alzheimer's Association’s Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring and were based on data from more than 2,100 Australian adults who were middle-aged or older. None of the participants had any history of dementia or cognitive decline.
Researchers examined participants’ eating habits alongside cognitive testing that measured things like visual attention and processing speed.
What the study found
According to the researchers, even a modest increase in ultra-processed food intake was linked to noticeable differences in focus.
The study noted that a 10% increase in ultra-processed foods was tied to lower performance on attention-related cognitive tests.
Ultra-processed foods can include items like packaged snacks, soft drinks, ready-made meals, and other heavily manufactured products. Researchers said participants in the study got about 41% of their daily energy intake from these foods, which closely reflects broader eating patterns in Australia.
One of the more surprising findings was that the connection remained even among people following otherwise nutritious eating patterns, including Mediterranean-style diets.
Researchers said that suggests the level of processing itself may play an important role.
“Food ultra-processing often destroys the natural structure of food and introduces potentially harmful substances like artificial additives or processing chemicals,” Dr Cardoso said.
“These additives suggest the link between diet and cognitive function extends beyond just missing out on foods known as healthy, pointing to mechanisms linked to the degree of food processing itself.”
The study did not find a direct link between ultra-processed foods and memory loss, but researchers emphasized that attention is still a critical part of brain health. Focus and processing speed help support learning, problem-solving, and other everyday cognitive functions.
For consumers, the findings are less about eliminating every packaged food and more about paying attention to how much of the diet comes from heavily processed products. Researchers say the study adds to growing evidence that brain health may be influenced not only by what nutrients people consume, but also by how foods are made.