Eating UPF can cause obesity, but that may not be the only factor linking highly processed food with upper aerodigestive cancers, researchers claim.
23 November 2023
Eating more ultra-processed food (UPF) may be associated with a higher risk of developing cancers of the upper aerodigestive tract (including mouth, throat and oesophageal cancers), according to a new study funded by World Cancer Research Fund and led by researchers from the University of Bristol and the International Agency for Research on Cancer (IARC).
The authors of this international study, which analysed diet and lifestyle data on 450,111 adults who were followed for approximately 14 years, say obesity associated with the consumption of UPFs may not be the only factor to blame. The study was published in the European Journal of Nutrition.
Several studies have shown a link between UPF and cancer, including a recent study which looked at the association between UPFs and 34 different cancers in the UK Biobank.
As many UPFs have an unhealthy nutritional profile, researchers from the Bristol Medical School and IARC sought to establish whether the association between UPF consumption and head and neck cancer and oesophageal adenocarcinoma (a cancer of the oesophagus) could be explained by an increase in body fat.
Results showed that eating 10% more UPF is associated with a 23% higher risk of head and neck cancer and a 24% higher risk of oesophageal adenocarcinoma in the largest cohort study in Europe, the European Prospective Investigation into Cancer and Nutrition cohort. Increased body fat only explained a small proportion of this statistical association.
Dr Helen Croker, World Cancer Research Fund’s Assistant Director of Research and Policy, said:
This study adds to a growing pool of evidence suggesting a link between UPF and cancer risk. The association between a higher consumption of UPF and an increased risk of developing upper-aerodigestive tract cancer supports our Cancer Prevention Recommendations to eat a healthy diet, rich in wholegrains, vegetables, fruit and beans.
Fernanda Morales-Berstein, the study’s lead author, said:
UPFs have been associated with excess weight and increased body fat in several observational studies. This makes sense, as they are generally tasty, convenient and cheap, favouring the consumption of large portions and an excessive number of calories. However, it was interesting that in our study the link between eating UPFs and upper-aerodigestive tract cancer didn’t seem to be greatly explained by body mass index and waist-to-hip ratio.
The authors suggest that other mechanisms could explain the association. For example, additives including emulsifiers and artificial sweeteners which have been previously associated with disease risk, and contaminants from food packaging and the manufacturing process, may partly explain the link between UPF consumption and upper-aerodigestive tract cancer in this study.
George Davey Smith, Professor of Clinical Epidemiology and Director of the MRC Integrative Epidemiology Unit at the University of Bristol, and co-author on the paper, said:
UPFs are clearly associated with many adverse health outcomes, yet whether they actually cause these, or whether underlying factors such as general health-related behaviours and socioeconomic position are responsible for the link, is still unclear.
Further research is needed to identify other mechanisms, such as food additives and contaminants, which may explain the links observed.
However, based on the finding that body fat did not fully explain the link between UPF consumption and upper-aerodigestive tract cancer risk in this study, Morales-Berstein said:
Focusing solely on weight loss treatment, such as Semaglutide, is unlikely to greatly contribute to the prevention of upper-aerodigestive tract cancers related to eating UPFs.
World Cancer Research Fund examines how diet, nutrition, body weight and physical activity affect your risk of developing and surviving cancer. As part of an international network of charities, we have been funding life-saving research, influencing global public health policy, and educating the public since 1982. While society continues searching for a cure, our prevention and survival work is helping people live longer, happier, healthier lives – free from the devastating effects of cancer. www.wcrf-uk.org and Twitter, Facebook, Instagram & LinkedIn.
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