Summary: A large international study found a direct association between eating ultra-processed foods (UPFs) and a measurable decline in the brain’s ability to sustain attention and process information quickly.
Following more than 2,100 middle-aged and older adults, researchers report that even a small daily increase in UPF intake — for example, adding a single packet of chips or a sugary drink — corresponds with a significant reduction in performance on standardized tests of attention and processing speed. This effect appeared independent of overall diet quality.
Key Facts
- The 10% Threshold: For every 10% rise in daily calories from ultra-processed foods, the study observed a measurable decline in visual attention. A 10% increase roughly equals adding one standard bag of chips or a soft drink to daily consumption.
- Processing Matters: Negative effects were seen even among participants who otherwise adhered to a Mediterranean-style eating pattern, indicating that the industrial processing and additives in UPFs may harm cognition independent of nutrient quality.
- Attention First: Although the study did not demonstrate an immediate link to memory loss, attention is a foundational cognitive skill required for learning and problem solving. Impairments in attention can therefore raise long-term dementia risk.
- Possible Mechanisms: Ultra-processing typically alters food’s natural structure and introduces additives and industrial chemicals. These changes may promote neuroinflammation or other pathways that contribute to cognitive decline.
Source: Monash University
New collaborative research from Monash University, the University of São Paulo and Deakin University shows a diet high in heavily processed foods can impair attention and increase conditions linked to dementia risk.
Published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring, a journal of the Alzheimer’s Association, this cross-sectional study assessed dietary patterns and cognitive performance in more than 2,100 dementia-free Australian adults aged approximately 40–70 years.
The study’s analysis shows that even a modest increase in a person’s intake of ultra-processed foods is linked to lower attention scores — regardless of whether their overall diet otherwise appears healthy.
Lead author Dr Barbara Cardoso, from the Department of Nutrition, Dietetics and Food and the Victorian Heart Institute at Monash University, emphasizes a clear connection between industrial food processing and cognitive performance.
“To put our findings in perspective, a 10 per cent increase in UPFs is roughly equivalent to adding a standard packet of chips to your daily diet,” Dr Cardoso explained. “For each 10 per cent rise in ultra-processed food consumption, we observed a distinct, measurable drop in the ability to focus. Clinically, this translated to lower scores on standardized tests of visual attention and processing speed.”
Participants reported obtaining about 41% of their daily energy from UPFs, closely matching the national Australian average of roughly 42%.
Examples of UPFs include soft drinks, packaged salty snacks and many ready-made meals — essentially products that depart from fresh, whole foods and contain industrially derived ingredients.
Because the negative association persisted independent of overall diet quality, including adherence to a Mediterranean-style diet, the researchers conclude that the level of processing itself may pose risks beyond simply missing beneficial foods.
“Ultra-processing often destroys the food’s natural cellular structure and adds artificial ingredients and processing chemicals,” Dr Cardoso said. “These factors point to mechanisms beyond nutrient deficiency that could influence cognition.”
Higher UPF intake was also linked to increases in modifiable dementia risk factors, such as elevated blood pressure and obesity — conditions that can be managed to reduce long-term risk.
While this cross-sectional study did not show a direct causal relationship between UPFs and memory loss, the observed decline in attention is clinically important because attention underpins many cognitive functions and can influence future dementia risk.
Funding: Data came from the Healthy Brain Project, supported by national and international research funders. Individual investigators received fellowship and grant support from several health research funding bodies.
Key Questions Answered:
A: According to this study, no. Harmful components and additives in ultra-processed foods appear to affect cognition independently of otherwise healthy choices. The degree of processing acts as its own risk factor.
A: Ultra-processed foods include soft drinks, packaged salty snacks, reconstituted meat products, and many ready-to-heat meals. A useful rule is that if an item contains industrial ingredients rarely used in home cooking — emulsifiers, artificial dyes, or flavor enhancers — it is likely a UPF.
A: The study highlights modifiable risk factors such as high blood pressure and obesity linked to UPF intake. Reducing UPF consumption and prioritizing whole foods can help protect attention and processing speed, and may lower long-term dementia risk.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full for accuracy.
- Additional context was added by editorial staff to aid reader understanding.
About this diet and neuroscience research news
Author: Barbara Cardoso
Source: Monash University
Contact: Barbara Cardoso – Monash University
Image: The image is credited to Neuroscience News
Original Research: Closed access. “Ultra-processed food intake, cognitive function, and dementia risk: A cross-sectional study of middle-aged and older Australian adults” by Barbara R. Cardoso, Euridice Martinez Steele, Barbara Brayner, Xinyi Yuan, Lisa Bransby, Hannah Cummins, Yen Ying Lim, Priscila Machado. DOI:10.1002/dad2.70335
Abstract
Ultra-processed food intake, cognitive function, and dementia risk: A cross-sectional study of middle-aged and older Australian adults
INTRODUCTION
Consumption of ultra-processed foods has been associated with more than 30 negative health outcomes, including key dementia risk factors such as cardiovascular disease, type 2 diabetes and obesity. This study examined whether UPF consumption is associated with cognitive performance and dementia risk scores and whether those associations remain after accounting for overall diet quality.
METHODS
This cross-sectional analysis included 2,192 Australian adults aged 40–70 years with no dementia diagnosis. Diet was assessed using a validated food-frequency questionnaire and categorized according to the NOVA classification. Cognitive testing used the Cogstate Brief Battery, and dementia risk was estimated with the CAIDE tool.
RESULTS
Each 10% increase in energy intake from ultra-processed foods was associated with lower attention scores (−0.05 points) and a higher dementia risk score (+0.24 points). These associations were independent of adherence to a Mediterranean-style diet.
DISCUSSION
Higher consumption of ultra-processed foods is linked to poorer attention and greater modifiable dementia risk, independently of overall diet quality. These results suggest the level of food processing and the presence of industrial additives may play a significant role in cognitive health and dementia prevention strategies.