Chips today, fog tomorrow? Study links processed foods to waning focus

Think twice before sinking your teeth into that salty potato chip. You may be dulling more than your hunger.

A growing body of research is sharpening concerns about ultra-processed foods – the packaged snacks, sugary drinks and ready-made meals that have become fixtures of modern diets.

A new study suggests that even modest increases in the consumption of these foods could chip away at one of the brain’s most essential functions: the ability to focus.

The research, led by scientists at Monash University in collaboration with the University of Sao Paulo and Deakin University, followed more than 2,100 Australian adults who were free of dementia.

Their eating habits were measured alongside tests of cognitive performance, particularly attention and processing speed – mental skills that underpin learning, decision-making and everyday tasks.

The conclusion was not dramatic, but it was consistent.

As the proportion of ultra-processed foods in a person’s diet increased, performance in attention-based tasks declined.

A 10 per cent increase in the consumption of such foods – roughly the equivalent of adding a daily packet of chips – was associated with a measurable drop in focus, said the study’s lead author, Dr Barbara Cardoso.

The effect held even among participants whose overall diets were otherwise considered healthy.

Higher dementia risk

Ultra-processed foods are typically engineered for convenience and shelf life. These often have additives, emulsifiers and other industrial ingredients.

Researchers say these processes can alter the structure of food in ways that may affect the brain, though the precise biological mechanisms remain under investigation.

Participants in the study derived about 41 per cent of their daily energy from ultra-processed foods, a figure that closely mirrors national consumption patterns in Australia and reflects a broader global trend.

The study, published in a journal of the Alzheimer’s Association, stopped short of linking these foods directly to memory loss or dementia.

But it did find associations with conditions that raise dementia risk, including obesity and high blood pressure.

Attention, researchers note, is often an early casualty in cognitive decline – and a foundation for more complex mental processes.

A gradual erosion in focus may not be immediately noticeable, but over time, it could have broader implications.

In a 2022 study published in the journal Neurology, researchers in China looked at the dietary habits of more than 72,000 people who were 55 years old and older without dementia and followed them over an average of 10 years.

By the end of the study period, 518 participants had been diagnosed with dementia.

The researchers observed a link between developing dementia and earlier intake of ultra-processed foods.

They estimated that replacing 10 per cent of ultra-processed foods in a diet with minimally processed or unprocessed food could reduce a person’s risk of developing dementia by 19 per cent.

For consumers, the message is less about alarm than awareness.

The occasional indulgence is unlikely to cause harm. But as ultra-processed foods quietly take up more space on the plate, their cumulative effects may be harder to ignore.