According to a new study published in JAMA Network Open, excessive consumption of ultra-processed foods in healthy adults is associated with signs of brain damage. In turn, these changes increase the likelihood of developing clinical stroke and memory problems later in life.
Researchers from McMaster University and the Population Health Research Institute (PHRI) used magnetic resonance imaging (MRI) to examine the brains of nearly 9,000 individuals. The analysis showed that participants with the highest intake of ultra-processed foods had small areas of brain damage far more frequently than those who consumed the least amount of such foods.
Specifically, the risk of exhibiting these changes was 40% higher in the highest intake group. While these micro-injuries do not produce noticeable symptoms, they are regarded as early warning signs that can appear years before the onset of stroke or cognitive decline.
“To be frank, I did not expect this result. We studied middle-aged Canadians who had no history of heart disease and reported no other medical complaints. Typically, this type of damage is associated with conditions we usually hear about and treat in much older populations,” noted Russell de Souza, the study’s first author and an associate professor at McMaster University.
The study included participants aged 35 to 69 years. The data revealed that individuals who consumed the most ultra-processed food had higher amounts of total body fat and deep abdominal (visceral) fat. This type of belly fat is linked to inflammatory processes and vascular damage that can reach the brain.
Notably, the link between ultra-processed foods and brain damage was more pronounced in women: those in the highest intake group showed signs of damage nearly twice as often as women in the lowest intake group.
“Our findings suggest that the relationship between diet and brain health may manifest well before people develop noticeable memory or cognitive problems. This adds to growing evidence that what individuals eat in their 30s, 40s, 50s, and 60s shapes their brain health later in life,” stated Sonia Anand, senior author of the study.
According to the researchers, ultra-processed foods often contain elevated levels of sodium, added sugars, and saturated fats, while being deficient in fiber, vitamins, and minerals. In the study, such foods accounted for an average of 25% of participants’ daily caloric intake, rising to 45% among the highest consumers (compared to only 16% in the lowest consumption group). Concurrently, as ultra-processed food intake rose, the share of minimally processed foods (such as fruits, vegetables, and whole grains) fell from 68% to 41%.
“Individuals who ate more ultra-processed foods were not merely adding them to their regular diet; these items were actively displacing healthy, whole foods,” de Souza added.
The authors also highlighted an important caveat: because the participants were evaluated at a single point in time without long-term longitudinal follow-up, the researchers cannot state definitively that ultra-processed foods directly caused these brain changes.
“We need longitudinal studies using repeat MRI scans over time to determine whether reducing ultra-processed foods can slow down or prevent these brain changes. Such a study is already underway,” explained Russell de Souza.
