How do ultra-processed foods affect health? Blood, urine markers may help show the impacts

South China Morning Post

21-05-2025

Molecules in blood and urine may reveal how much energy a person consumes from ultra-processed foods, a key step to understanding the impact of the products that make up nearly 60 per cent of the American diet, a new study finds.
It is the first time that scientists have identified biological markers that can indicate higher or lower intake of the foods, which are linked to a host of health problems, said Erikka Loftfield, a National Cancer Institute researcher who led the study published earlier this week in the journal PLOS Medicine.
'It can potentially give us some clues as to what the underlying biology might be between an ultra-processed food association and a health outcome,' Loftfield said.
Ultra-processed foods – such as instant noodles, sugary cereals, carbonated soft drinks, potato and tortilla chips and frozen pizzas – are products created through industrial processes with ingredients such as additives, colours and preservatives not found in home kitchens.
They are ubiquitous in the United States and elsewhere, but studying their health impacts is hard because it is difficult to accurately track what people eat.
Potato and tortilla chips, an ultra-processed food, are displayed in a pharmacy in New York. Photo: AP
Typical nutrition studies rely on recall: asking people what they ate during a certain period. But such reports are notoriously unreliable because people do not remember everything they ate, or they record it inaccurately.