October 20, 2026, 11:48 am | Read time: 5 minutes

Potential Health Effects of Ultra-Processed Foods

Ultra-processed foods, often referred to by the English abbreviation UPF for “ultra-processed foods,” account for more than half of daily energy intake in many high-income countries, according to the study.

Previous studies have already identified links between higher UPF consumption, increased fat accumulation, and an unfavorable cardiometabolic risk profile. Possible mechanisms include higher energy intake, impaired appetite regulation, metabolic disorders, inflammatory processes, and vascular damage.

The focus of the current investigation from Canada was another question. Could vascular changes in the brain already be present before measurable cognitive performance impairments appear? The researchers examined whether the intake of ultra-processed foods was related to body fat percentage, visceral fat tissue (deep abdominal fat), liver fat content, as well as vascular damage in the brain and cognitive performance.

The vascular changes examined included significant stress from so-called white matter hyperintensities, noticeable changes in the brain’s white matter on MRI, and clinically unnoticed brain infarcts (“silent,” symptomless small strokes). These findings were collectively considered vascular brain damage.

Study Design and Methods

The cross-sectional analysis (a study at a single point in time) by McMaster University and other Canadian research institutions included 8,783 adults aged 35 to 69 years without cardiovascular disease. The average age was 57.7 years, and 56.6 percent of participants were women. Participants provided information about their diet over the previous year using validated questionnaires. The researchers classified the consumption of ultra-processed foods according to the NOVA system—a food classification that divides foods into four groups based on their level of industrial processing.¹

Body fat percentage, visceral fat, and liver fat were examined, as well as vascular damage in the brain captured via MRI. Cognitive performance was assessed using two cognitive tests. In the statistical analysis, researchers considered factors such as age, gender, education, physical activity, smoking, diabetes, hypertension, and total energy intake. Since all measurements were taken at a single baseline, there was no follow-up.

What the Study Data Show About Body Fat and the Brain

On average, about 42 percent of participants’ daily energy intake came from ultra-processed foods. In the lowest quartile, consumption was a median of 3.1 UPF servings per 2,000 kilocalories daily, while in the highest quartile, it was 12.8 servings.

Higher UPF consumption was associated with more body fat. Participants in the highest quartile had, after statistical adjustment, an average of 1.7 percentage points higher body fat and 5.7 milliliters more visceral fat than those in the lowest quartile. This association was particularly evident in individuals with obesity (a body mass index of 30 or higher), while no significant difference was measured in those with normal weight (BMI under 25). In the primary analysis, no significant association was found with liver fat.

Vascular brain damage was also more frequently observed with higher UPF consumption. Its prevalence was 8.1 percent in the lowest quartile and 11.3 percent in the highest quartile. After statistical adjustment, the odds for such changes were 40 percent higher in the highest quartile. For every additional five UPF servings per 2,000 kilocalories daily, the odds for vascular brain damage were 16 percent higher and for clinically unnoticed brain infarcts 21 percent higher.

A particularly striking result emerged when separating by gender: The association with vascular changes in the brain was almost exclusively found in women in detailed analyses (78 percent higher odds in the highest quartile), while no statistically significant association was found in men. However, this finding proved less robust: When UPF consumption was calculated as a proportion of total food servings or energy intake, the association was no longer statistically significant.

No consistent association was found between cognitive performance and UPF consumption. This could also be due to the participants’ very high level of education (over 73 percent with a college degree) and consistently high scores on thinking and memory tests (known as a ceiling effect). Such simple tests often cannot capture very early, mild changes in the brain.

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What Do the Results Mean?

The most pronounced association was between higher UPF consumption and increased body and visceral fat. Whether the observed vascular brain changes are later linked to cognitive decline remains open.

Longitudinal studies—investigations over a longer period with multiple measurement points—must clarify whether higher UPF consumption actually precedes such changes.

Also interesting: “Not All Ultra-Processed Foods Are Unhealthy”

Study Context and Possible Limitations

A strength of the investigation was the combination of dietary data with objective measurement methods. Body fat, visceral fat, liver fat, and vascular changes in the brain were assessed using magnetic resonance imaging, among other methods.

The key limitation, however, concerns the study design. Since all measurements were taken at a single point in time, neither a temporal sequence nor a cause-and-effect relationship can be demonstrated. The study does not show that ultra-processed foods cause vascular damage in the brain. Reverse causality cannot be ruled out either.

Additionally, diet was estimated using a single questionnaire about consumption in the previous year. This may inadequately capture long-term dietary habits. Furthermore, UPF represents a heterogeneous food category. Different ultra-processed foods may therefore be differently associated with health characteristics.