Study shows correlations between consumption of different types of ultra-processed foods and mortality

People who eat more ultra-processed foods have a "slightly higher" mortality rate, according to an analysis published in The BMJ. The study analysed data from more than 110,000 people followed up for over 30 years in the United States. The correlation between ultra-processed food intake and all-cause mortality was strongest for the meat, poultry and seafood group. 

09/05/2024 - 00:30 CEST
Expert reactions

240509 ultraprocesados - Carmen Romero EN

Carmen Romero Ferreiro

Lecturer of the Degree in Human Nutrition and Dietetics and Head of Research for the Degree in Nutrition at the Francisco de Vitoria University

Science Media Centre Spain

This US study examined the relationship between ultra-processed foods and risk of death over more than 30 years of follow-up. It was based on a large sample of nurses and health professionals, exceeding 150,000 participants with no history of cancer, cardiovascular disease or diabetes. 

This research contributes to the available body of evidence on the negative health effects of ultra-processed foods. It found that those who consumed a greater amount of these foods had a slightly higher risk of death compared to those who consumed less. This risk was especially notable in deaths from neurodegenerative diseases. 

The study provides novel results by examining the link of specific subgroups of ultra-processed foods to mortality. Ready-to-eat meat, poultry and seafood products were found to be associated with increased all-cause mortality, as were sugar-sweetened and artificially sweetened beverages, dairy desserts and ultra-processed breakfast products. 

It is important to note that the sample consisted mainly of health professionals, which limits the generalisability of the results to other populations. Furthermore, being an observational study, a causal relationship between the consumption of ultra-processed foods and mortality cannot be established. 

Despite these limitations, the study suggests that limiting certain ultra-processed foods may have long-term health benefits. This has important implications for clinical practice and public health policy, as it provides further evidence that should be taken into account in dietary recommendations and regulation of unhealthy foods.

The author has declared they have no conflicts of interest

240509 ultraprocesados - Javier Sánchez Perona EN

Science Media Centre Spain

For some years now, the scientific output on ultra-processed foods has been enormous. Many studies have shown associations between the consumption of these products and various diseases, including cardiovascular diseases, neurodegenerative diseases, diabetes, cancer, mental disorders, etc., as well as mortality. In fact, several 'umbrella' reviews of all these studies have been published in recent months, drawing unequivocal conclusions. On the one hand, the consumption of ultra-processed foods is associated with poorer health and, on the other hand, there is no evidence to show that ultra-processed foods can be healthy. 

The only evidence suggesting that ultra-processed foods may have some benefit comes from a study that investigated the association of these foods with multimorbidity, in particular, the co-existence of at least two chronic diseases in an individual between cancer, cardiovascular disease and type 2 diabetes. That study found that consumption of some subcategories of ultra-processed foods, such as cereals, breads and vegetable-based products, were not associated with these comorbidities. Although the study did not make associations with these individual diseases, it highlighted the need to study subcategories of ultra-processed foods. 

In this regard, the study now published investigates the relationship of 9 subcategories of ultra-processed foods, which had previously been classified as such using the NOVA system. The study collected consumption data from more than 100,000 health professionals from two of the largest research cohorts of the last decades. 

The most relevant results show the association between the intake of these subcategories of ultra-processed foods and mortality from various diseases. Ready-to-eat meat, poultry and seafood products showed the strongest and most consistent associations, followed by sugar-sweetened and artificially sweetened beverages, and dairy desserts. No subcategories could be robustly associated with a reduction in mortality risk for the diseases studied, with the exception of 'snacks and sweet packaged desserts'. Consumption of these products was associated with small reductions of 6-7% in mortality from cancer and cardiovascular disease, which is explained by the presence of dark chocolate and chocolate with nuts in this subcategory. In contrast, consumption of snacks and sweet packaged desserts was associated with an 18% increased risk of mortality from neurodegenerative diseases.  

Like all studies, this one also has its limitations. In addition to being an observational study and therefore precluding the establishment of causal relationships, I think the most important shortcoming is that the food consumption questionnaires were not specifically designed to measure ultra-processed food consumption. This is because, at the time of the study's inception, these products had not been defined as such. Therefore, it is possible that the results could have been different, which calls for prospective research from this point onwards.  

In any case, this is the first large study to associate consumption of subcategories of ultra-processed products with mortality from certain diseases. The main conclusion is that, while there are differences between groups of ultra-processed foods, they are all associated with increases in total mortality and mortality due to different diseases, supporting the current evidence for reducing ultra-processed foods in the population. Translated with (free version)

The author has declared they have no conflicts of interest

240509 ultraprocesados - Maira Bes-Rastrollo EN

Maira Bes-Rastrollo

Professor of Preventive Medicine and Public Health at the University of Navarra and researcher at the Institute for Health Research of Navarra (IdiSNA) and the CIBERobn

Science Media Centre Spain

Once again, it is observed that the consumption of ultra-processed foods increases the risk of mortality from all causes, so we have more scientific evidence supporting the need to take urgent measures to discourage their consumption and promote the consumption of fresh and minimally processed foods. 

This time the results come from a large observational study with a very solid scientific methodology and repeated measures of the diet, analyzing data from two American cohort studies: the Nurses' Health Study and the Health Professionals Follow-up Study carried out at Harvard University. The analyses include 74,563 women and 39,501 men without cancer, cardiovascular disease, or diabetes at the beginning of the study. There were 30,188 deaths in women and 18,005 deaths in men after a median follow-up of 34 and 31 years, respectively. 

Unlike previous results, the authors did not find an association of risk with cardiovascular mortality or cancer, so the observed risk relationship may be explained by an increase in neurodegenerative mortality and other causes. According to the authors, these differences are because other studies include distilled beverages in the calculation of ultra-processed foods and do not adequately consider smoking habits throughout life. This claim is not correct, as at least one of the published studies did adjust the analyses for pack-years of consumption, and when the effect of ultra-processed foods on never-smokers —restriction: no tobacco confusion was observed—even higher risk was observed.  

On the other hand, the authors, based on their results, conclude that the nutritional quality of ultra-processed foods has a more predominant influence on mortality than the consumption per se of these foods. However, there is a lot of previous literature that states that the risk relationship of ultra-processed foods with health is due not only to their nutritional quality but also to their processing. In fact, previous results from the SUN cohort showed that even with equal intake of saturated fatty acids, trans fatty acids, added sugars, sodium, or taking into account adherence to the Mediterranean diet, ultra-processed foods remained a risk factor for mortality. 

In addition to the nutritional quality, different reasons have been postulated that can explain this dangerous effect: overconsumption of these foods due to their easy consumption and great palatability; displacement of other more nutritious foods; lack of intake of health-protective phytochemicals present in fruits, vegetables, and legumes; presence of toxic contaminants created during processing or released from packaging materials; and consumption of a 'cocktail' of potentially harmful additives to health if consumed together and in the long term.  

The NOVA system for classifying foods according to their degree of processing has not been without criticism for being a classification that includes a wide variety of food groups, as suggested by the article's authors. Indeed, it is not perfect, but it is a clear, useful, and easy-to-apply classification that can be incorporated into public health messages reminding the importance of consuming fresh and minimally processed foods to gain health and many years of life without disability.

The author has declared they have no conflicts of interest
Association of ultra-processed food consumption with all cause and cause specific mortality: population based cohort study
  • Research article
  • Peer reviewed
  • Observational study
  • People
Publication date

Zhe Fang et al.

Study types:
  • Research article
  • Peer reviewed
  • Observational study
  • People
The 5Ws +1
Publish it