Ultra-Processed Foods Linked to Brain Health Risks

A study published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring adds to growing concerns about the role of ultra-processed foods (UPFs) in long-term health, this time focusing on brain function and dementia risk. The team of investigators wanted to understand whether eating more highly processed foods is linked to changes in thinking skills and future risk for dementia, even when overall diet quality is taken into account.

What Did the Team Study?

The study included more than 2,100 adults in Australia between the ages of 40 and 70 who did not have dementia. Investigators assessed participants’ diets using a detailed questionnaire and categorized foods based on how processed they were using the Nova system.

Cognitive function was measured using a standardized tool that evaluates skills like attention and memory, while dementia risk was estimated using the cardiovascular risk factors, aging, and incidence of dementia (CAIDE) dementia risk score, which looks at factors such as age, blood pressure and lifestyle.

Importantly, the team also accounted for how closely participants followed a Mediterranean-style diet, which is often considered a gold standard for healthy eating, to determine whether food processing itself plays a unique role.

What Were the Key Findings?

The study found clear associations between higher consumption of ultra-processed foods and certain aspects of brain health:

• Lower attention performance: For every 10% increase in UPF intake, attention scores slightly declined.
• Higher dementia risk scores: Increased UPF intake was linked to higher scores on a tool that estimates future dementia risk.
• No link with memory: Investigators did not find a significant association between UPF intake and memory performance.
• Independent of overall diet quality: These findings held true even for people who otherwise followed a Mediterranean-style diet.

“To put our findings in perspective, a 10% increase in UPFs is roughly equivalent to adding a standard packet of chips to your daily diet,” said lead investigator Barbara Cardoso, Ph.D., from the Department of Nutrition, Dietetics and Food and the Victorian Heart Institute at Monash University. “For every 10% increase in ultra-processed food a person consumed, we saw a distinct and measurable drop in a person’s ability to focus. In clinical terms, this translated to consistently lower scores on standardized cognitive tests measuring visual attention and processing speed.”

What Does This Mean for Patients?

Ultra-processed foods include items such as packaged snacks, sugary drinks, processed meats and ready-to-eat meals. These foods are often high in added sugars, unhealthy fats and additives — and low in nutrients.

This study suggests that how food is processed may matter just as much as what nutrients it contains. Even if someone follows a generally healthy diet, regularly consuming large amounts of ultra-processed foods could still impact brain health, particularly attention and factors linked to dementia risk.

While this study does not prove that ultra-processed foods cause dementia, it adds to evidence that limiting these foods may support overall brain health. For patients, small changes, such as choosing whole, minimally processed foods more often, could be a meaningful step toward protecting cognitive function over time.

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