Eating more ultra-processed foods (UPFs) may be associated with a higher risk of developing cancers of the upper aerodigestive tract (ie, the mouth, throat and oesophagus), according to a new study in the European Journal of Nutrition. The authors of this study, led by the University of Bristol and the International Agency for Research on Cancer (IARC), say that obesity associated with the consumption of UPFs may not be the only factor to blame.
Several studies have identified an association between UPF consumption and cancer, including a recent study which looked at the association between UPFs and 34 different cancers in the largest cohort study in Europe, the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, which followed 450 111 adults who for approximately 14 years.
As more evidence emerges about the associations between eating UPFs and adverse health outcomes, researchers from the Bristol Medical School and IARC wanted to explore this further.
Since many UPFs have an unhealthy nutritional profile, the team sought to establish whether the association between UPF consumption and head and neck cancer and oesophageal adenocarcinoma in EPIC could be explained by an increase in body fat.
Results from the team’s analyses showed that eating 10% more UPFs is associated with a 23% higher risk of head and neck cancer and a 24% higher risk of oesophageal adenocarcinoma in EPIC.
Increased body fat only explained a small proportion of the statistical association between UPF consumption and the risk of these upper-aerodigestive tract cancers.
Fernanda Morales-Berstein, a Wellcome Trust PhD student at the University of Bristol and the study’s lead author, explained: “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.
Fernanda Morales-Berstein and colleagues did caution that the associations between UPF consumption and upper-aerodigestive tract cancers found in the study could be affected by certain types of bias.
This would explain why they found evidence of an association between higher UPF consumption and increased risk of accidental deaths, which is highly unlikely to be causal.
Inge Huybrechts, Team head of the Lifestyle exposures and interventions team at IARC, added: “Cohorts with long-term dietary follow-up intake assessments, considering also contemporary consumption habits, are needed to replicate these study’s findings, as the EPIC dietary data were collected in the 1990s, when the consumption of UPFs was still relatively low. As such associations may potentially be stronger in cohorts including recent dietary follow-up assessments.”
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 greatly explain the link between UPF consumption and upper-aerodigestive tract cancer risk in this study, Fernanda Morales-Berstein, suggested: “Focussing 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.”
Source: University of Bristol
