Instant noodles, soft drinks, sweetened breakfast cereals and ready meals: Ultra-processed food means not only missing recommended grains and proteins, but it can also leave you at risk of “silent stroke” and cognitive decline by middle age, researchers in Canada say.
After testing around 9,000 people aged 35 to 69, scientists at McMaster University and the Population Health Research Institute (PHRI) found those with the “highest intake” of processed food to be 40% more likely to exhibit a form of brain damage that “may increase the chances of clinical stroke and future memory problems”.
Silent strokes show no obvious symptoms, but can cause permanent damage and are seen as early warning signs that can appear years before a major stroke.
“I would not have expected this finding frankly,” said study first author, McMaster associate professor and PHRI nutritional epidemiologist Dr Russell de Souza.
He added that the impact is usually “associated with conditions we hear about and treat at a much older age”.
Processed food made up around a quarter of the participants’ diets, although some reached up to 40%, crowding healthy food out of their eating, according to the team, whose work was published in Jama Network Open, an American Medical Association journal.
“Our findings suggest that the link between diet and brain health may be detectable before people experience noticeable problems with memory or thinking,” said study senior author, McMaster professor of medicine and epidemiology, and PHRI senior scientist Dr Sonia Anand, warning that what people eat while young could affect their cognitive capacity later in life.
Longer-term tracking, including using magnetic resonance imaging (MRI) scans, could be needed to further investigate the connection, the researchers said.
In September (2026), a University of California team in the United States called for large-scale tests to confirm a connection between a junk food habit and vulnerability to depression after 20 patients in their study reported improved symptoms, such as reduced anxiety, after switching to a healthier diet. – dpa
