A recent study conducted by Canadian researchers found a correlation between high consumption of ultra-processed foods and an increased risk of stroke and future memory problems in healthy adults.
Using magnetic resonance imaging (MRI) scans to examine the brains of about 9,000 participants, the researchers discovered small areas of brain damage more commonly in people who ate large amounts of ultra-processed foods, such as soft drinks, packaged snacks and sugary breakfast cereals.
Those with the highest intake of ultra-processed foods were 40% more likely to show these changes in the brain, which can go undetected because they don’t produce obvious symptoms, Medical Xpress reported.
These brain changes can, however, be early warning signs in the years before the onset of a stroke or memory problems.
These findings were unexpected, according to Russel J. de Souza, first author of the study and an associate scientist at the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences.
“Usually, this kind of damage is associated with conditions we hear about and treat at a much older age,” de Souza told Medical Xpress. He noted that the study focused on “middle-aged Canadians who had no heart problems and reported no other health concerns.”
The study, which was published in JAMA Network Open, included participants between the ages of 35 and 69.
Participants who ate the most ultra-processed foods held more body fat and visceral fat, which is linked to various health concerns including heart disease.
The study found an overall stronger connection between the consumption of ultra-processed foods and brain damage among female participants.
Women in the highest consumption group had nearly twice the likelihood of exhibiting signs of brain damage as opposed to those in the lowest consumption group.
“Our findings suggest that the link between diet and brain health may be detectable before people experience noticeable problems with memory or thinking,” said Sonia Anand, senior author of the study and senior scientist at PHRI.
Ultra-processed foods are usually tasty, but they frequently lack important nutrients such as fiber, vitamins and minerals, while containing high amounts of sodium, saturated fats and added sugars, according to the CDC.
The average percentage of total daily calories consumed from ultra-processed foods was 55% among Americans ages one year and older between August 2021 and August 2023, according to data published by the CDC in August 2025.
Ultra-processed foods are convenient and widely available, which could contribute to high consumption, Anand said. However, she noted that “diets high in these foods may be linked to brain changes that may lead to memory loss and stroke” in the future.
For participants in this study, ultra-processed foods accounted for an average of about 25% of their daily food intake.
The researchers noticed that, as consumption of ultra-processed food increased, consumption of nutrient-dense foods decreased.
Whole foods like fruits, vegetables and grains made up 41% of the daily food intake for participants who ate the most ultra-processed food and 68% for those who ate the least.
The study’s findings suggest a connection between consumption of ultra-processed foods and indicators of changes in the brain.
Despite this, because participants were only evaluated once and not followed up with in the future, the researchers could not determine that the direct cause of the changes in the brain was consumption of ultra-processed foods.
“We need longer-term studies that track people over time with repeated MRI scans to find out whether reducing ultra-processed food intake can slow or prevent these brain changes,” de Souza said, adding that follow-up research is in the works.
