Researchers from Monash University, the University of Sao Paulo and Deakin University report that diets heavy in industrially processed foods are linked to poorer performance on measures of attention, along with an increased risk of developing dementia. The findings, published in Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, a journal of the Alzheimer's Association, come from an analysis of the diets and cognitive health of more than 2,100 dementia-free Australian adults in middle age and later life.
The detail that stands out is how small the dietary shift needed to be. According to the researchers, even a slight increase in daily ultra-processed food intake corresponded to a measurable drop in attention span - and that held even among people whose diets were otherwise healthy. In other words, the effect did not appear to be simply a matter of ultra-processed items crowding out vegetables, whole grains and other beneficial foods.
Lead author Dr Barbara Cardoso, of Monash University's Department of Nutrition, Dietetics and Food and the Victorian Heart Institute, said the results reinforce a clear connection between industrial food manufacturing and cognitive decline. For clinicians and for anyone thinking about long-term brain health, that reframes ultra-processed foods as something more than a general nutrition concern - the study points to how food is manufactured, not only what nutrients it contains, as relevant to cognition.
The work examined existing diets and cognitive measures rather than testing a change in eating patterns, so it establishes an association rather than proving that ultra-processed foods directly cause attention to falter. Its value lies in the scale of the sample and in identifying attention as a specific cognitive domain worth tracking in future research on diet and dementia risk.