Canadian Study Links Ultra-Processed Food to Signs of Brain Damage in Younger Adults

Ultra-processed foods (UPF) such as packaged snacks, sugary drinks, processed meats, and ready-to-eat meals may affect not only waistlines but also brain health. A study published in JAMA Network Open found that middle-aged adults who consumed high amounts of UPF were 40% more likely to show signs of small blood vessel damage in the brain on MRI scans than those with low consumption. The findings are surprising because the study participants were generally healthy and showed no symptoms of cognitive impairment.

The research, involving nearly 9,000 Canadians aged 35–69 with no history of heart disease, analyzed data from two large cohorts: the Canadian Alliance for Healthy Hearts and Minds and the Prospective Urban and Rural Epidemiology-MIND. Participants completed detailed diet questionnaires and underwent brain scans. The neurologists who assessed the MRI results did not know the participants' eating habits, reducing bias. Foods were classified by the level and purpose of industrial processing.

As a result, those with the highest UPF intake—reaching 45% of their daily portions—were 40% more likely to have small areas of brain damage, known as white matter hyperintensities and silent brain infarcts, compared with the lowest-intake group (16% of daily portions). This difference appeared before any perceptible symptoms. "The brain changes we studied are not benign," said Russell de Souza, lead author of the study and a scientist at the Population Health Research Institute (PHRI) at McMaster University, as quoted by Medical News Today. "They are markers of cerebrovascular disease that have been linked to stroke risk, cognitive decline, and dementia later in life."

Although the 40% figure sounds large, de Souza cautioned that it is important to distinguish relative and absolute risk. "If about 1 in 10 people have this MRI finding, a 40% increase in relative risk means about 14 in 100 people, not 10 in 100. The individual risk increase is indeed moderate, but because UPF is consumed by most of the population, the impact could be significant at the population level," he explained. He also stressed that this observational study cannot prove a causal relationship, even though the analysis model accounted for other risk factors.

Interestingly, the strongest association was seen in women. Those with the highest UPF consumption were nearly twice as likely to show signs of brain damage as the lowest consumers. De Souza called the finding an "intriguing signal" that needs further research, not a definitive conclusion that women are more susceptible. Differences in body fat distribution, vascular biology, hormonal factors—including changes during menopause—and the types of UPF consumed may explain this variation. "Two people can consume the same amount of UPF but from very different sources with different nutritional profiles," he added.

In addition, the highest UPF consumers tended to have more body fat and visceral abdominal fat, which is linked to inflammation and cardiometabolic risk. A diet high in UPF is also associated with obesity and metabolic problems that can affect blood vessels. "The brain depends on a healthy vascular network to supply oxygen and nutrients. Over time, factors that damage blood vessels can contribute to vascular brain injury," de Souza said. However, the researchers could not yet determine whether body fat, inflammation, or blood vessel damage explains the link.

The study also highlights that UPF is not simply added to a balanced diet but replaces whole foods rich in nutrients and fiber. The highest UPF consumption group got only 41% of their daily portions from whole foods, while the lowest group reached 68%. This is compounded by affordability, convenience, availability, and marketing factors that make UPF more accessible, especially for people with limited time and money. This condition could widen health disparities.

Nevertheless, not all UPF has an identical nutritional profile. The study does not show that every food in that category carries the same risk. De Souza suggested simple swaps: water instead of sugary drinks, plain yogurt instead of processed snacks, and adding beans or lentils to meals. "Affordable and practical options such as beans, lentils, oats, frozen vegetables, frozen fruit, eggs, milk, plain yogurt, peanut butter, and canned fish are often highly nutritious and suit many household budgets," he said. "Small, consistent changes can have a big impact over time."

For Indonesia, these findings are relevant given that consumption of processed foods and packaged sugary drinks continues to rise, especially in urban areas. Data from the Basic Health Research (Riskesdas) shows that the prevalence of obesity and type 2 diabetes continues to climb, while access to fresh food remains a challenge in some regions. This study strengthens the argument for food policies that encourage whole-food consumption, including through nutrition education and front-of-pack labeling regulations. The question is whether the current diets of Indonesia's younger generation will take a toll on their brain health twenty years from now?