In a recently published study, Dr Lancet Regional Health, Researchers have investigated the relationship between ultra-processed food (UPF) consumption and the risk of many diseases including cancer, cardiovascular disease and type 2 diabetes.
Study: Consumption of ultra-processed foods and multimorbidity risk of cancer and cardiometabolic disease: a multinational cohort study. Image credit: Daisy Daisy/Shutterstock.com
Over the past two decades, the number of people with multiple chronic diseases has increased significantly, especially in high-income countries. It is now rising in low and middle income areas.
In Europe, about 50 million people suffer from multimorbidity, defined as at least two chronic diseases. These conditions result in reduced quality of life, disability, functional decline, and high healthcare costs. Identifying preventable risk factors is essential to reduce its impact.
The global increase in UPF consumption, which constitutes 50-60% of daily energy intake in some countries, is alarming. UPFs are manufactured industrially, often as packaged foods such as cereals, biscuits, reconstituted meats, instant noodles, and sweetened beverages.
Studies have linked UPF consumption to a higher risk of cardiovascular disease, type 2 diabetes, cancer and obesity, a potential multi-disease risk factor. Given their increasing prevalence and shared risk factors, more research is needed to understand how consumption of ultra-processed foods contributes to the co-occurrence of major chronic diseases such as cancer, cardiovascular disease and type 2 diabetes.
About the study
Initiated between 1992 and 2000, the European Prospective Investigation in Cancer and Nutrition (EPIC) study involved approximately 520,000 participants from 23 centers across 10 European countries.
The study primarily targeted adult volunteers aged 35 to 74 years, and significantly, participant demographics differed across centers; For example, only women were enrolled in Norway, Utrecht, France, and Naples, and specific groups such as state-school employees in France and members of local blood donor associations in Italy and Spain were included. The Oxford cohort in the United Kingdom (UK) was independent, with half of the participants following a vegetarian or vegan diet.
For this study, after excluding data from France, Greece and Norway and removing participants with pre-existing conditions such as cancer or cardiovascular disease, a final cohort of 266,666 participants was formed, of which 60% were women. Participants underwent regular follow-up every 3–4 years for major disease updates.
Ethical approval for the study came from the International Agency for Research on Cancer (IARC) and the Institutional Review Board of each EPIC center, and participants provided written informed consent.
Their dietary habits in the previous year were accurately recorded using country-specific food-frequency questionnaires, which were then categorized into different food groups. An important aspect of this classification was the use of the Nova food classification system to identify UPF.
The study accurately collected data on participants’ socio-demographic and lifestyle factors, including educational level, smoking status, physical activity, menopausal status, and hormone use. Body mass index (BMI) was calculated using measured height and weight.
To ensure data accuracy, a rigorous approach was adopted with complete case analysis and minimal missing data. Outcomes such as cancer incidence and cardiovascular disease were verified through cancer registries, medical records, and hospital data.
Advanced multivariable Cox proportional hazards models were used for analyses, adjusting for factors such as energy and alcohol intake and physical activity.
The study also conducted comprehensive sensitivity analyzes as well as detailed subgroup analyzes of UPFs and their links to multiple diseases. Although the participants were not involved in determining the research questions or results, there were plans to disseminate the results publicly.
Results of the study
The current comprehensive study analyzed 266,666 participants, 60% of whom were women. Baseline characteristics revealed that women and men consumed an average UPF of 326 g/day and 413 g/day, respectively, excluding alcoholic beverages.
This intake represents about one-third of their daily caloric intake. During a median follow-up period of 11.2 years, 4,461 participants developed multimorbidities including cancer and cardiometabolic disease. The most common multimorbidity patterns are cancer among people with cardiovascular disease, followed by type 2 diabetes and type 2 diabetes among people with cardiovascular disease.
The study’s multivariable-adjusted Cox model highlighted a positive association between higher UPF consumption (per 1 standard deviation (SD) increase, roughly 260 g/day) and risk of many diseases even after adjusting for BMI.
These findings were consistent across the transition from baseline to multimorbidity, with similar patterns for individual noncommunicable diseases (NCDs) such as cancer, cardiovascular disease, and type 2 diabetes. The association was particularly strong for type 2 diabetes, although it was somewhat attenuated after further adjustment for BMI.
An in-depth analysis of UPF subgroups revealed that consumption of animal-based products and artificially and sugar-sweetened beverages were positively associated with the risk of many diseases. Conversely, ultra-processed breads and cereals showed an inverse association with some uncertainty.
Other UPF subgroups, including sweets, confections, savory snacks, and ready-to-eat mixed foods, were not significantly associated with risk of many diseases.
The robustness of these results was confirmed by several sensitivity analyzes that included combinations of factors, such as the inclusion of ultra-processed alcoholic beverages and animal-based products. Importantly, the associations observed were somewhat attenuated when accounting for soft drink intake or focusing on the caloric proportion of UPF in the diet.
These sensitivity analyzes underscore the complexity of the relationship between UPF consumption and many diseases and highlight the need for a better understanding of dietary effects on health.
Overall, the study presents a thorough examination of the association between UPF consumption and the risk of several diseases, providing valuable insight into the potential health effects of these foods.
The comprehensive nature of the analysis, including different subgroups and susceptibility testing, contributes significantly to the current understanding of food-related health risks.