Ultra-processed foods tied to silent brain injury in midlife

Clinical takeaway: Encourage middle-aged patients to limit ultra-processed foods and replace them with minimally processed options, as high intake may be linked to early cerebrovascular injury detectable years before stroke or cognitive symptoms appear.

Ultra-processed foods now account for a large share of calories in many high-income countries, yet their effects on brain health before the onset of clinical disease remain unclear. Researchers examined whether these foods were associated with adiposity, MRI evidence of vascular brain injury, and cognition in adults without cardiovascular disease.

In this cross-sectional analysis of 8,783 Canadian adults aged 35-69 years, participants consumed a mean 42% of daily calories from ultra-processed foods. Researchers assessed diet, body composition, cognitive performance, and brain MRI findings, focusing on covert brain infarcts and high white-matter hyperintensity burden, markers of subclinical cerebrovascular disease.

Compared with participants in the lowest quartile of ultra-processed food intake, those in the highest quartile had about 40% greater odds of MRI-defined vascular brain injury. Vascular brain injury was detected in 11.3% of the highest-intake group versus 8.1% of the lowest-intake group. Higher intake was also associated with greater adiposity, including a 1.7-percentage-point higher body fat percentage and roughly 8% greater visceral adipose tissue volume. Associations with vascular brain injury persisted after adjustment for demographic, lifestyle, and cardiometabolic factors.

Notably, the association appeared stronger among women. Women in the highest intake quartile had a 78% higher likelihood of vascular brain injury than those in the lowest quartile, whereas no significant association was observed among men. Despite the MRI findings, ultra-processed food intake was not associated with performance on the Montreal Cognitive Assessment or Digit Symbol Substitution Test, suggesting structural brain changes may precede measurable cognitive decline.

“Usually, this kind of damage is associated with conditions we hear about and treat at a much older age,” said first author Russell J. de Souza, ScD. “We studied middle-aged Canadians who had no heart problems and reported no other health concerns.”

Source: de Souza RJ, et al. (2026 Oct 15) JAMA Netw Open. Ultraprocessed Food Intake and Adiposity, Vascular Brain Injury, and Cognition in Middle-Aged Adults