Ultraprocessed foods have been linked to a growing list of health concerns. New research suggests they may also be associated with something people notice in everyday life: the ability to focus.
In a cross-sectional study of more than 2,100 middle-aged and older Australian adults without dementia, researchers found that higher intake of ultraprocessed foods was associated with lower scores on tests of attention and processing speed. The study, published in Alzheimer’s & Dementia Diagnosis Assessment & Disease Monitoring, does not prove that ultraprocessed foods caused those differences, but it adds to ongoing research into how food processing may relate to brain health.
The study, led by researchers at Monash University, the University of São Paulo and Deakin University, examined participants’ usual diets alongside standardized measures of cognitive function. Participants consumed about 41% of their daily calories from ultraprocessed foods, similar to the Australian national average reported by the researchers.
“To put our findings in perspective, a 10 percent increase in UPFs is roughly equivalent to adding a standard packet of chips to your daily diet,” said lead author Dr. Barbara Cardoso, from Monash University.
For every 10% increase in ultraprocessed food intake, researchers found lower scores on tests measuring visual attention and processing speed. Those skills help support learning, problem-solving and other everyday mental tasks.
“For every 10 percent increase in ultraprocessed food a person consumed, we saw a distinct and measurable drop in a person’s ability to focus,” Cardoso said.
The findings are notable because the association remained even when researchers accounted for overall diet quality. In other words, adults who otherwise followed a healthier eating pattern still showed lower attention scores when a larger share of their diet came from ultraprocessed foods.
That does not mean one snack or ready-made meal will harm focus. Ultraprocessed foods are a broad category, and not all of them have the same nutritional profile. The study points instead to a broader pattern of intake and raises questions about whether the degree of processing may matter alongside nutrients, calories and overall diet quality.
The researchers did not find a direct association between ultraprocessed food intake and memory loss. They also could not determine whether ultraprocessed foods contributed to lower attention scores or whether other factors, such as sleep, stress, physical activity or overall health, played a role.
Still, the study adds to a larger conversation about how highly processed eating patterns may relate to long-term brain health. Researchers noted that ultraprocessed foods may affect the body in ways that go beyond missing out on healthier foods, including through changes to food structure, additives or compounds formed during processing.
“Food ultraprocessing often destroys the natural structure of food and introduces potentially harmful substances like artificial additives or processing chemicals,” Cardoso said.
The study used data from the Healthy Brain Project, which is funded by the National Health and Medical Research Council, the Alzheimer’s Association, the Dementia Australia Research Foundation, the Bethlehem Griffiths Research Foundation, the Yulgilbar Alzheimer’s Research Program, the National Heart Foundation of Australia and the Charleston Conference for Alzheimer’s Disease. Additional researcher support came from FAPESP and NHMRC fellowships and grants.