Ultra-Processed Foods May Be Quietly Affecting Your Brain’s Ability to Focus

Ultra-processed foods are pervasive in Western diets, and new research has linked these industrially produced meals, drinks, and snacks to poorer brain health.

Specifically, the study explored the correlation between attention, dementia risk, and the proportion of ultra-processed foods in the diets of more than 2,000 dementia-free Australians aged 40–70.

Nutritional biochemist Barbara Cardoso from Monash University in Australia led the analysis of survey data from 2,192 participants (mostly White women), who completed a food questionnaire and four cognitive function tests assessing attention and memory.

The participants also provided demographics, physical activity levels, and other health details, which allowed the researchers to calculate their risk of dementia with an established tool for predicting the likelihood of a diagnosis within 20 years among middle-aged people.

While an observational study like this can’t determine if there’s any causal relationship between ultra-processed foods and brain health, it did reveal patterns between the two that could be investigated further.

Across the entire group, ultra-processed foods made up about 41 percent of total energy intake, though this proportion was significantly higher among younger participants and men.

For every 10 percent increase in ultra-processed foods in a person’s diet, there was a distinct, measurable drop in their ability to focus of about 0.05 points. More ultra-processed foods were associated with higher dementia risk, too, adding about 0.24 points to the score for each 10 percent increase.

“To put our findings in perspective, a 10 percent increase in ultra-processed foods is roughly equivalent to adding a standard packet of chips to your daily diet,” Cardoso says.

“In clinical terms, this translated to consistently lower scores on standardized cognitive tests measuring visual attention and processing speed.”

The study also revealed a few other factors associated with higher ultra-processed food intake: lower educational attainment, obesity, and lower adherence to the Mediterranean diet. It found no correlation between ultra-processed food intake and memory scores.

But following a ‘healthy’ diet like the Mediterranean, which previous studies have associated with better brain function, made little difference if ultra-processed foods were still part of the equation.

This, the study’s authors write, could indicate that food processing itself could be affecting cognitive health, rather than a dietary lack of nutrients.

For the purposes of this study, ultra-processed foods included things like soft drinks, potato chips, ready-made meals, dairy desserts, and hot dogs – basically, anything that isn’t a fresh, ‘whole’ food.

It’s a very broad category, which makes it difficult to narrow down why the relationship between brain health and diet exists – but researchers have a few theories.

“Food ultra-processing often destroys the natural structure of food and introduces potentially harmful substances like artificial additives or processing chemicals,” Cardoso explains.

“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.”

Additives are one possible explanation, but there are many others.

For one, ultra-processed foods are also linked to metabolic conditions such as diabetes, high blood pressure, and obesity, which in turn can affect brain function.

On the flip side, people with lower attention scores and higher dementia risk might be more prone to eating ultra-processed foods in the first place. Where someone lives also directly impacts their access to healthy food options.

Related: This Unique Diet Could Slow Your Brain Aging by Over 2 Years, Study Suggests

Further research will be needed to unpack exactly what’s going on here. Still, it’s enough to consider swapping that hot dog for a salad sandwich – wholegrain, of course.

The research was published in Alzheimer’s and Dementia: Diagnosis, Assessment & Disease Monitoring.