Summary: A new international study found a clear association between eating ultra-processed foods (UPFs) and a measurable decline in the brain’s ability to focus.
Researchers followed more than 2,100 middle-aged and older adults and discovered that even a modest daily increase in UPF intake — for example, adding a single packet of chips or a sugary soft drink — was linked to lower performance on standard tests of attention and processing speed, independent of overall diet quality.
Key Findings
- Ten percent effect: For each 10% increase in daily energy from ultra-processed foods, participants showed a measurable drop in visual attention. A 10% rise is approximately the energy content of a typical bag of chips or a can of soda.
- Processing matters: The association persisted even among people who otherwise followed a healthy Mediterranean-style diet, indicating that the degree of processing itself — not just missing nutrients — may harm cognitive function.
- Attention as a foundation: While the study did not demonstrate immediate memory loss linked to UPFs, attention is fundamental to learning and problem-solving; reductions in attention can therefore increase long-term dementia risk.
- Potential mechanisms: Ultra-processing often alters food’s natural cellular structure and introduces additives and industrial chemicals. These substances may promote neuroinflammation and other processes that undermine brain health.
Source: Monash University
Overview of the study
Researchers from Monash University, the University of São Paulo and Deakin University report that diets high in ultra-processed foods are associated with poorer attention and an increased profile of modifiable dementia risk factors. The work was published in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring and analyzed data from more than 2,100 dementia-free Australian adults aged roughly 40–70 years.
Participants in the study consumed, on average, about 41% of their daily energy from ultra-processed foods, closely matching the Australian national average. UPFs include items such as soft drinks, packaged salty snacks, reconstituted meat products and many ready-to-eat or heat-and-eat meals — essentially foods containing industrial ingredients or additives rarely found in a home kitchen.
Lead author Dr Barbara Cardoso, from Monash University’s Department of Nutrition, Dietetics and Food and the Victorian Heart Institute, emphasized that the findings point to a specific link between industrial food manufacturing and declines in cognitive processing speed and attention.
“A 10 per cent increase in UPFs is roughly equivalent to adding a standard packet of chips to your daily diet,” Dr Cardoso said. “For each 10 per cent rise in ultra-processed food intake we observed a consistent, measurable reduction in the ability to focus, reflected in lower scores on standardized tests of visual attention and processing speed.”
Because the study found these associations regardless of adherence to a Mediterranean-style diet, researchers suggest the physical and chemical changes produced by ultra-processing — the destruction of natural food structure and the introduction of additives and processing byproducts — may be important drivers of cognitive harm.
Higher UPF consumption was also associated with an increase in modifiable dementia risk factors, including conditions such as high blood pressure and obesity. These are factors that can be managed through lifestyle change and medical treatment, giving practical pathways to reduce risk.
Although this cross-sectional analysis did not show a direct, immediate link between UPFs and memory loss, it highlights attention as a key early indicator: when attention and processing speed decline, the brain’s capacity to learn, reason and solve problems is weakened, which over time may raise the likelihood of dementia.
Funding and acknowledgements: The study used data from the Healthy Brain Project and received support from multiple research funders including the National Health and Medical Research Council (NHMRC), the Alzheimer’s Association, and other foundations. Individual researchers received fellowships and grants from national and international bodies as noted by the authors.
Frequently asked questions
A: According to this study, no. The harmful compounds and additives in ultra-processed foods appear to affect cognitive function independently of other healthy choices. The degree of processing itself acts as a separate risk factor.
A: Ultra-processed foods include soft drinks, packaged salty snacks, many ready-made meals, and reconstituted meat products. If a product contains industrial ingredients such as emulsifiers, artificial dyes or flavor enhancers not typically used in home cooking, it is likely a UPF.
A: The study links UPF intake to modifiable risk factors like hypertension and obesity. Because these conditions can be managed or improved, reducing UPF consumption and increasing whole, minimally processed foods offers a realistic way to protect attention and lower long-term dementia risk.
Editorial notes
- This article was edited by a Neuroscience News editor and reviewed against the full journal paper.
- Additional context was provided by editorial staff to clarify clinical implications and public health relevance.
About this research
Author: Barbara Cardoso
Source: Monash University
Contact: Barbara Cardoso – Monash University
Image: Image credit 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” — Cardoso et al., Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring. DOI provided by the journal.
Abstract
Title: Ultra-processed food intake, cognitive function, and dementia risk: A cross-sectional study of middle-aged and older Australian adults
INTRODUCTION
Ultra-processed food consumption has been linked to more than 30 adverse health outcomes, including several established dementia risk factors such as cardiovascular disease, type 2 diabetes and obesity. This study examined whether UPF consumption relates to cognitive performance and dementia risk scores, and whether these relationships stand after accounting for overall diet quality.
METHODS
This cross-sectional analysis included 2,192 dementia-free Australian adults aged 40–70. Dietary intake was measured with a validated food frequency questionnaire and categorized using the NOVA classification. Cognitive function was assessed with the Cogstate Brief Battery and dementia risk estimated with the CAIDE score.
RESULTS
Each 10% increase in UPF energy was associated with lower attention scores (−0.05 points) and higher dementia risk (+0.24 points), independent of adherence to a Mediterranean-style diet.
DISCUSSION
Higher intake of ultra-processed foods is associated with reduced attention and greater modifiable dementia risk, even when overall diet quality is accounted for. These findings suggest limiting UPFs and prioritizing whole foods could support cognitive health and reduce long-term dementia risk.