Ultra-processed foods: too many ready meals may increase cancer risk by almost 25%

Ultra-processed foods (UPF) are a large staple in many people's diets, but they have been linked to poor health and an increased risk of cancer. Now, researchers at the University of Bristol and the International Agency for Research on Cancer (IARC) found eating more UPFs may be associated with a higher risk of developing cancers in the upper aerodigestive tract - including mouth, throat and the oesophagus.

UPFs are easy to spot by looking at the label of the product or by reading the ingredients - if it contains five or more ingredients not used when cooking at home, the food is likely to be highly processed.

The researchers analysed diet and lifestyle data from 450,111 adults over 14 years and found those eating 10% more UPFs was associated with a 23% higher risk of head and neck cancer and a 24% higher risk of oesophageal cancer.

Increased body fat only went a small way in explaining the link between UPF consumption and the risk of these three cancers, researchers noted.

Fernanda Morales-Berstein, a Wellcome Trust PhD student at the University of Bristol and 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 researchers said that additives like emulsifiers and artificial sweeteners often found in UPFs could be a cause of this heightened risk, but they also found a link between higher UPF consumption and increased risk of accidental deaths so further information is needed.

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, as the association with accidental deaths draws attention to.”