New findings on the health impacts of ultra-processed foods have prompted calls from researchers for policies that “urgently disincentivize” consumption of UPFs, which have been linked to 32 different diseases including cardiovascular disease, obesity, diabetes, some cancers, and depression.
A study analyzing data from nationally representative dietary surveys and mortality data from eight countries (Australia, Brazil, Canada, Chile, Colombia, Mexico, United Kingdom, and United States) shows that premature deaths attributable to consumption of ultra-processed foods (UPFs) increase significantly according to their share in individuals’ total energy intake.
The researchers behind the study, published this month in the American Journal of Preventive Medicine, say their work looked beyond the individual impact of high levels of critical nutrients (sodium, trans fats, and sugar) and additionally accounts for the changes to foods which occur during industrial processing and the use of artificial ingredients, including colourants, artificial flavours and sweeteners, emulsifiers, and many other additives and processing aids. Assessing deaths from all-causes associated with UPF consumption, they say, allows an overall estimate of the effect of industrial food processing on health.
The researchers define UPFs as “ready-to-eat-or-heat industrial formulations that are made with ingredients extracted from foods or synthesized in laboratories, with little or no whole foods in their composition”. These, they say, have gradually been replacing traditional foods and meals made from fresh and minimally processed ingredients.
Lead investigator of the study Eduardo Augusto Fernandes Nilson, DSc, Oswaldo Cruz Foundation (Fiocruz), Brazil, says: “UPFs affect health beyond the individual impact of high content of critical nutrients (sodium, trans fats, and sugar) because of the changes in the foods during industrial processing and the use of artificial ingredients, including colourants, artificial flavours and sweeteners, emulsifiers, and many other additives and processing aids, so assessing deaths from all-causes associated with UPF consumption allows an overall estimate of the effect of industrial food processing on health.”
While previous studies focused on specific dietary risk factors instead of food patterns, the current study modelled data from nationally representative dietary surveys and mortality data from eight countries (Australia, Brazil, Canada, Chile, Colombia, Mexico, United Kingdom, and United States) to link dietary patterns, considering the extent and purpose of industrial food processing, to deaths from all causes.
“We built a model that estimated that the percentage of all-cause premature preventable deaths due to the consumption of UPFs can vary from 4% in countries with lower UPF consumption to almost 14% in countries with the highest UPF consumption”
Dr. Nilson explains, “We first estimated a linear association between the dietary share of UPFs and all-cause mortality, so that each 10% increase in the participation of UPFs in the diet increases the risk of death from all causes by 3%. Then, using the relative risks and the food consumption data for all countries (ranging from 15% of the total energy intake in Colombia, to over 50% of the calories in the United States), we built a model that estimated that the percentage of all-cause premature preventable deaths due to the consumption of UPFs can vary from 4% in countries with lower UPF consumption to almost 14% in countries with the highest UPF consumption. For example, in 2018, 124,000 premature deaths were attributable to the consumption of UPFs in the United States.”
High consumption of UPFs has been associated with 32 different diseases, including cardiovascular disease, obesity, diabetes, some types of cancer, and depression. For the first time, this study has estimated the burden of UPF intake on premature deaths from all-causes in different countries, showing that the attributable mortality is significant in all settings and that addressing UPF consumption should be a global public nutrition priority.
Dr. Nilson notes: “It is concerning that, while in high-income countries UPF consumption is already high but relatively stable for over a decade, in low- and middle-income countries the consumption has continuously increased, meaning that while the attributable burden in high-income countries is currently higher, it is growing in the other countries. This shows that policies that disincentivize the consumption of UPFs are urgently needed globally, promoting traditional dietary patterns based on local fresh and minimally processed foods.”
Well conducted study
Commenting on the study, Prof Nita Forouhi, Professor of Population Health and Nutrition, MRC Epidemiology Unit, University of Cambridge, said: “There are limitations to this paper, including the points the authors themselves raised. We already know that correlation does not necessarily mean causation. But well conducted observational studies with long term prospective cohort data are often the best we are going to get realistically; we will not get randomised controlled trials (RCTs) of behaviours awaiting death or chronic disease events, and RCTs have their own biases and limitations, particularly for behavioural factors (different to taking medication vs placebo studies). So we should not ignore such findings, especially as the current research has reported consistently similar associations in several countries which increases the degree of confidence.”