People who eat more ultra-processed foods (UPFs) are at a substantially greater risk of developing type 2 diabetes, concludes a new study published in The Lancet.
 
Researchers at University of Cambridge and Imperial College London found that, across 311,892 participants of the previous EPIC study tracked for 10.9 years on average, every 10% increase in the amount of ultra-processed foods in a person’s diet was linked with a 17% increase in type 2 diabetes risk. This risk could be lowered by consuming more whole foods instead.
 
The researchers assessed the degree of processing in foods using the Nova classification, which divides foods into four groups, one of which is UPFs. The highest-risk UPFs in the study were savory snacks, animal-based products like processed meats, ready meals, and sugar- and artificially-sweetened beverages, suggesting that these products in particular should be given attention.
 
The exact link between UPFs and type 2 diabetes isn’t fully confirmed, but simple overconsumption and weight gain is a leading factor, authors note. In the present study, “increased body fat” was involved in half of the associations between UPFs and diabetes.
 
“More studies to date only consider UPF as a whole, but we also suspect that there may be different risks associated with different types of UPF, and the risks of other processing groups have not been well-researched. Our analysis goes a step further than previous studies, by looking at all four processing groups in the Nova classification to gauge the impact on type 2 diabetes risk when we substitute UPF with less processed foods, as well as looking at nine UPF subgroups,” said Samuel Dicken, first author of the study from University of Cambridge’s division of medicine. “The good news is that replacing UPF with less processed foods was associated with a reduced type 2 diabetes risk.”
 
In the study, researchers broke down UPF into nine subgroups, to better understand how levels of processing affect type 2 diabetes risk. Additionally, they performed substitution modeling to see how, theoretically, replacing one Nova food group with another would affect type 2 diabetes risk. The nine subgroups were: breads, biscuits, and breakfast cereals; sauces, spreads, and condiments; sweets and desserts; savory snacks; plant-based alternatives; animal-based products; ready-to-eat/heat mixed dishes; artificially and sugar-sweetened beverages; alcoholic drinks; and other ultra-processed foods.
 
For instance, substituting 10% of ultra-processed foods with 10% processed foods reduced diabetes risk by 18%. Processed foods included beer, wine, salted nuts, artisanal breads, and preserved fruits and vegetables.
 
In the top 25% of UPF consumers, where UPF made up 23.5% of the diet, sweetened beverages alone accounted for nearly 40% of UPF intake and 9% of dietary intake overall.
 
Comparatively, UPF breads, biscuits, and breakfast cereals, sweets and desserts, and plant-based alternatives were associated with a lower incidence of type 2 diabetes.
 
“The UPF subgroup analysis in this study has been revealing and confirms that not all food categorized as UPF are alike in terms of the health risks associated with them,” said Rachel Batterham, professor and senior author of the study. “Breads and cereals, for example, are a staple of many people’s diets. Based on our results, I think we should treat them differently to savory snacks or sugary drinks in terms of the dietary advice we provide.”
 
The team of researchers is currently conducting a trial to assess ultra-processed versus minimally-processed diets, which will further clarify the results of this study.
 
While the present study “cannot determine causal relationships” between UPFs and chronic diseases, “it does suggest that reducing consumption of some UPF and replacing them with unprocessed, whole foods, might lower risk of type 2 diabetes,” said Mark Gunter, an author of the study from the Imperial College of London and one of the EPIC study coordinators.