Washington, D.C.: Scientists have made a significant breakthrough in understanding the health impacts of ultra-processed foods (UPFs), revealing that molecules found in blood and urine can reliably indicate how much of these foods a person consumes.
The findings, published this week in PLOS Medicine, mark the first time researchers have identified biological markers that correlate with UPF intake. The study, led by Erikka Loftfield of the U.S. National Cancer Institute, could pave the way for more accurate assessments of how these foods affect long-term health.
Ultra-processed foods—such as sugary cereals, fizzy drinks, crisps, frozen meals, and packaged snacks—are heavily manufactured and often contain additives, artificial colours, and preservatives rarely found in home cooking. While their prevalence has soared in high-income countries, linking their consumption to specific health outcomes has proven difficult due to challenges in tracking people’s diets with precision.
To address this, Loftfield and her team analysed data from over 1,000 older U.S. adults, more than 700 of whom had submitted both blood and urine samples alongside detailed dietary reports over the course of a year. The researchers discovered that hundreds of metabolites—molecules created through digestion and metabolic processes—were associated with the percentage of energy participants consumed from ultra-processed foods.
From this data, the team developed a predictive “signature” made up of 28 blood markers and up to 33 urine markers that could reliably reflect an individual’s UPF intake. “We found this signature that was predictive of a dietary pattern high in ultra-processed food—not just a specific item here and there,” said Loftfield.
Notably, two amino acids and one carbohydrate repeatedly appeared in over 60% of testing iterations, and one marker showed a potential link between high UPF intake and type 2 diabetes.
Experts are calling the discovery a major step forward. “This is a major scientific advance,” said Dr. Dariush Mozaffarian, director of the Food Is Medicine Institute at Tufts University, who was not involved in the research. “With further study, these metabolic signatures could help clarify how UPFs impact health, including the role of processing methods and additives.”
Loftfield hopes to apply the biomarker tool to existing datasets with blood and urine samples to explore possible links between UPF consumption and conditions such as cancer.
“There’s strong scientific, public, and political interest in understanding whether ultra-processed foods are harming our health—and if so, why,” she added.
