Middle-aged adults who consume more ultra-processed foods may be more likely to show signs of silent strokes, according to a study examining the diets and brain scans of nearly 9,000 healthy Canadians between the ages of 35 and 69.

Silent strokes are small areas of brain damage that occur without obvious symptoms. Although people may not realize they have experienced them, the damage can signal an increased risk of future strokes and cognitive problems.

Researchers found that participants who consumed the most ultra-processed foods, accounting for nearly half of their daily food servings, were 40% more likely to have tiny areas of brain damage than those who ate the least. The association was strongest among women.

Lead author Russell J. de Souza of McMaster University and Hamilton Health Sciences in Canada said the findings were notable because this type of brain damage is typically associated with medical conditions identified and treated later in life.

The researchers also found that participants with the highest consumption of ultra-processed foods had the greatest amount of deep abdominal fat. This type of fat has been linked to inflammation and damage to blood vessels, potentially providing one explanation for the observed association between diet and brain health.

Senior author Dr. Sonia Anand, also of McMaster University and Hamilton Health Sciences, said the results suggest that the relationship between diet and brain health may become detectable before people experience noticeable difficulties with memory or thinking.

The findings highlight the potential importance of dietary habits throughout adulthood. According to Anand, what people eat between their 30s and 60s may influence their brain health later in life.

However, the study does not establish that ultra-processed foods directly cause silent strokes or brain damage. The researchers said further, longer-term studies are needed to determine whether the foods themselves contribute to the damage or whether other factors help explain the association.