Study Links Ultra-Processed Food to Declines in Attention and Cognitive Speed
Introduction
A new study by researchers from Monash University, the University of São Paulo, and Deakin University has found a clear link between eating more ultra-processed foods and measurable drops in attention and mental processing speed. This effect remained even among participants whose overall diets were considered healthy, which suggests that the level of food processing itself may affect brain function.
Main Body
The study, published in a journal of the Alzheimer’s Association, involved over 2,100 middle-aged Australian adults who did not have dementia at the start. Researchers measured their food intake and gave them cognitive tests focused on attention and processing speed. They found that a 10% increase in the amount of ultra-processed food in a person's diet—about the same as eating one extra packet of chips per day—was linked to a statistically significant drop in attention scores. On average, participants got about 41% of their daily energy from ultra-processed foods. This number is similar to the national average in Australia and reflects trends seen around the world. These results are consistent with earlier research. For example, a 2022 study from Harvard Medical School reported a 25% higher risk of dementia among people who ate more ultra-processed foods. Another study, published in Neurology in 2022, followed over 72,000 Chinese adults aged 55 and older for an average of 10 years. The researchers estimated that replacing 10% of ultra-processed foods with less processed alternatives could reduce dementia risk by 19%. Separate work by Virginia Tech University linked processed meats and sugary drinks to worse memory and thinking in adults. Additionally, a 2023 study from Ohio State University found that the average attention span of U.S. adults is now eight seconds, although experts note that many factors contribute to attention problems. Dr. Barbara Cardoso, the lead author and a biochemist at Monash University, stated that the additives and industrial ingredients common in ultra-processed foods are likely the main cause of the cognitive effects, rather than simply the lack of nutrients found in whole foods. Dr. Evita Singh, a psychiatrist at Ohio State University, commented that many variables can affect focus and attention. The study did not prove that ultra-processed foods directly cause dementia, but it did find links to intermediate risk factors such as obesity and high blood pressure. The researchers emphasized that the biological pathways are still being investigated. Ultra-processed foods make up about 60% of the U.S. diet, according to the study’s authors. Many products often seen as relatively healthy—such as granola bars and plant-based meat alternatives—fall into this category because of their additive content. The authors caution that while eating these foods occasionally is unlikely to cause harm, the long-term effects of regular consumption may slowly damage cognitive function over time.
Conclusion
This research supports a consistent pattern linking ultra-processed food consumption to reduced cognitive performance, especially in attention. Although the exact mechanisms are not yet fully understood, the findings suggest that choosing foods based on how processed they are may have small but significant effects on brain health over the long term.