Scepticism over ‘ultra-processed’ food study
Research published in JAMA Internal Medicine last month found an association between the proportion of ultra-processed foods consumed and overall mortality. The NutriNet-Santé cohort study, of 44,551 healthy French adults aged 45 or older, claimed a 10% increase in the proportion of ultra-processed food consumption was “statistically significantly associated” with a 14% higher risk of all-cause mortality.
However, Professor Julian Cooper, chair of the Scientific Committee at the Institute of Food Science & Technology, said ‘ultra-processed foods’ was “very unclear and confusing terminology” that required further research due to significant limitations.
“Foods, such as snacks, desserts and some meats, enable consumers to have convenient, safe and shelf-stable choices,” he added. “Approved additives keep food in a good condition, preserving nutritional quality.”
While acknowledging that the “large, carefully conducted” study found a “statistically significant” association between ultra-processed foods and mortality, Dr Ian Johnson, emeritus fellow at Quadram Institute Bioscience believed it was very difficult to draw any firm conclusions.
“The consumption of ultra-processed foods was linked to many measures of general nutritional quality, as well as to other lifestyle factors.” Johnson said. “The authors have made great efforts to correct for such confounders, but many others probably remain unknown – and as they state, ‘no causality can be established for the observed associations’.”
NHS dietitian Catherine Collins pointed out that the highest intake of “arbitrarily defined” ultra-processed foods was reported by those on the lowest income, living alone, male, a current smoker, obese, or reporting low levels of physical activity. “All these factors are independent predictors of mortality, potentially unrelated to dietary intake,” she said.
Professor Nita Forouhi of the Epidemiology Unit at the University of Cambridge recognised the “well-known limitations” of observational research. However, she added: “The case against highly processed foods is mounting.”
