- A study of more than 2,100 adults found that higher ultra-processed food intake was linked with poorer attention and slower mental processing.
- The association was seen even among people who otherwise followed healthier dietary patterns.
- The findings suggest food processing itself may matter for brain health, not just whether someone eats enough healthy foods.
Ultra-processed foods may affect focus and mental processing, even in people who otherwise eat fairly well.
Researchers from Monash University, the University of São Paulo and Deakin University analysed data from more than 2,100 middle-aged and older adults without dementia.
They looked at diet quality, ultra-processed food intake and cognitive performance.
Participants got around 41% of their daily calories from ultra-processed foods.
That is close to the Australian national average.
The researchers found that every 10% increase in ultra-processed food intake was linked with lower scores on tests of attention and processing speed.
A 10% increase is roughly equivalent to adding a standard packet of crisps to the daily diet.
The finding is important because attention is not a minor function.
It underpins learning, problem-solving, decision-making and everyday concentration.
The study also found that the association appeared regardless of overall diet quality.
Even people following a Mediterranean-style diet showed poorer attention scores when ultra-processed food intake was higher.
That suggests the issue may not simply be missing out on healthy foods.
The processing itself may be part of the problem.
Ultra-processed foods often contain additives, altered food structures and processing by-products.
They are also frequently high in salt, sugar and unhealthy fats.
- Ultra processed foods may raise asthma risk in children
- Ultra-processed food intake linked to poorer thigh muscle quality
- Ultra-processed foods linked to lower fertility and slower early embryo development
The researchers also found higher ultra-processed food intake was linked with dementia risk factors such as obesity and high blood pressure.
This does not prove that ultra-processed foods cause dementia or directly damage attention.
The study was observational.
But it adds to a growing picture.
Ultra-processed foods may affect health in ways that go beyond weight and blood sugar.
They may also be linked to how clearly we think and how well we focus.
