Replacing ultra-processed foods in diet associated with reduction in type 2 diabetes risk

Research by scientists at Imperial College London and the University of Cambridge demonstrated a greater risk of developing type 2 diabetes among people who eat the most amount of UPF.

It also said that the risks appeared to be lowered even by switching to processed food that had been less refined. Furthermore, the diabetes risk varied within the most processed UPF category, depending upon the particular foodstuff.

The Lancet Regional Health – Europe published study analysed UPF intake and health outcomes for 311,892 individuals from eight European countries over an average of nearly 11 years: in that period 14,236 people developed type 2 diabetes.

Every 10% increase in the amount of UPFs in an individual’s diet linked with a 17% increase in type 2 diabetes risk, suggested the research – a risk that could be countered by switching to food with a lower degree of processing.

Highest risk UPF groups were savoury snacks, animal-based products such as processed meats, ready meals, and sugar-sweetened and artificially-sweetened beverages.

The research referenced the Nova classification system, the standard measure for food processing. Its four categories are:

• Minimally processed foods (MPF) including unprocessed food – a category that includes eggs, milk and fruit
• Processed culinary ingredients like salt, butter and oil
• Processed food – tinned fish, cheese, beer etc
• UPF foods, encompassing ready-to-eat/heat mixed dishes, savoury snacks, sweets and desserts

Samuel Dicken, first author of the study from UCL Division of Medicine, said: “We know that ultra-processed foods are associated with a higher risk of certain diseases such as type 2 diabetes. As expected, our findings confirm this link and show that every 10% increase in the diet from UPF increases the risk of developing type 2 diabetes considerably.

However, he added that more work was needed into the variations between individual  UPF foods.

“Most 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,” stated Dicken.

He said his group’s analysis went further than previous studies, looking at all four processing groups in the Nova classification to gauge the impact on type 2 diabetes risk when substituting UPF with less processed foods. Additionally it looked at nine UPF subgroups.

In the study, researchers from UCL analysed data from the EPIC study, which has investigated the relationship between diet, lifestyle, and environmental factors, and the incidence of chronic diseases in more than half a million Europeans over time.

The researchers modelled the data to test how, theoretically, replacing one Nova food group impacted type 2 diabetes risk. This demonstrated that substituting 10% of UPF with 10% of MPF/PCI reduced diabetes risk by 14%, while substituting with 10% of PF reduced it still further, by 18% overall.

However, the authors noted that 30-50% of PF intake in their study derived from alcohol, specifically beer and wine – associated with lower risk of type 2 diabetes in an earlier EPIC study. The category also includes salted nuts, artisanal breads, and preserved fruits and vegetables.

Additionally, analysis of nine UPF subgroups showed that savoury snacks, animal-based products, ready meals, and sugar-sweetened and artificially-sweetened beverages were associated with higher incidence of type 2 diabetes.

Sweetened drinks comprised nearly 24% of total diet for the top quartile of UPF consumers; among these people UPF accounted for 23.5% of total diet, with almost 40% of that portion accounted for by sweetened beverages, which also comprised 9% of their diet overall.

This contrasted with other UPF subgroup foods including breads, biscuits and breakfast cereals, sweets, desserts, and plant-based alternatives which were associated with lower incidence of type 2 diabetes.

Professor Rachel Batterham, senior author of the study from UCL Division of Medicine, said: “The UPF subgroup analysis in this study has been revealing and confirms that not all foods categorised as UPF are alike in terms of the health risks associated with them.

“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 savoury snacks or sugary drinks in terms of the dietary advice we provide.”

While the study can only measure validly associations rather than causal effects, UCL’s team is conducting a trial to assess the impact of UPF versus MPF diets meeting healthy diet guidance, with results expected next year.

Pic: Behnam Norouzi