Food choices often focus on calories, protein, or vitamins, yet a growing body of research is turning attention toward something less obvious: how food is processed.
A recent analysis from Australia points to a striking link between ultraprocessed foods and changes in brain health, even when overall diet quality appears balanced. Items like chips, candy bars, frozen meals, sugary cereals, and soda were central to this pattern.
The research suggests that the way food is manufactured may play a role in cognitive function and long-term brain risk.
Small Dietary Shifts, Measurable Brain Changes
The study, led by Barbara Cardoso, PhD, from Monash University in Notting Hill, Australia, examined how ultraprocessed food intake relates to attention and dementia risk indicators. The data showed a consistent pattern:
Each 10% increase in ultraprocessed food intake corresponded to a 0.05-point drop in composite attention scores (95% CI -0.09 to -0.01, P=0.012) in adults aged 40 and older.
In parallel, dementia risk scores rose by 0.24 points (95% CI 0.16–0.32, P<0.001) on the modified CAIDE scale, a widely used tool that estimates long-term dementia risk based on lifestyle and health factors.
Cardoso described the shift in simple terms:
“For every 10% increase in ultraprocessed food a person consumed, a distinct and measurable drop in a person’s ability to focus was seen.”
That 10% increase equals roughly 150 grams per day, about the size of a standard packet of potato chips.
Attention Affected, Memory Unchanged
A key detail in the findings is the difference between cognitive functions. Attention showed a clear association with ultraprocessed food intake, while memory did not show a statistically significant link in this dataset.
Researchers noted that attention plays a foundational role in learning, decision-making, and information processing. Because of that, early changes in attention may appear before broader cognitive decline becomes visible.
The study states:
“Given that attention is foundational to many cognitive operations, such as learning, problem-solving, and memory formation, it is plausible that early disruptions in attention may precede broader cognitive impairments.”
Still, the researchers emphasized that more work is needed to understand how these patterns develop over time.
How the Study Was Conducted
The analysis included 2,192 dementia-free adults between 40 and 70 years old from the Healthy Brain Project in Australia. The average participant age was 56.6 years, and 75.4% were women.
Diet intake was measured using validated online food frequency questionnaires. Foods were grouped using the NOVA classification system, which separates foods into four categories:
1. Unprocessed or minimally processed foods
2. Processed culinary ingredients
3. Processed foods
4. Ultraprocessed foods
Cognitive performance was evaluated using the Cogstate Brief Battery, an online testing tool that produced two main outcomes: attention and memory composite scores.
A subgroup of 1,891 participants also completed CAIDE dementia risk scoring, which blends modifiable and non-modifiable risk factors.
Processing Over Nutrients Alone
One of the central points raised by the researchers is that the effect does not appear to be fully explained by diet quality alone. Even participants following a Mediterranean-style eating pattern showed similar associations when ultraprocessed food intake increased.
Cardoso noted that processing itself may alter food in ways that matter for brain health, stating that ultraprocessing can disrupt natural food structure and introduce compounds not found in minimally processed foods.
This aligns with a broader shift in nutrition science, where attention is moving beyond nutrients toward food structure and industrial processing methods.
Broader Health Context and Limitations
Earlier research has already linked ultraprocessed foods with higher dementia risk, faster cognitive decline in midlife, cardiovascular disease, certain cancers, and overall mortality risk. In many countries, these foods account for about 60% of daily calorie intake.
Despite the strong patterns observed, the study carries limitations. Data relied on self-reported food questionnaires, which can introduce reporting errors. The participant pool also leaned toward women with higher education levels and higher socioeconomic status compared to the general population in Australia, which may limit broader applicability.
Researchers also caution that the relationship with memory remains unclear and requires longer-term studies to map changes across different cognitive stages.
The findings from this Australian analysis add weight to growing evidence that ultraprocessed foods may influence brain health in measurable ways. Even modest increases in intake showed links to reduced attention performance and higher dementia risk scores, independent of overall diet patterns.
While memory outcomes did not shift in the same way, attention changes may represent an early signal worth tracking in future research.