The research study looked at 150,000 French adults, and they found that if the proportion of ultra-processed food in the diet increased by 10%, then the risk of cancer increased by 12%.
However, a team of researchers based in France and Brazil, set out to evaluate potential associations between ultra-processed food intake and risk of overall cancer, as well as that of breast, prostate, and bowel (colorectal) cancers. (Only 153 people got colorectal cancer, and Touvier says she believes there weren't enough cases to prove an association.) No strong connection was observed between ultra-processed foods and prostate cancer.
But firm evidence linking intake to risk of disease is still scarce. The participants logged what they ate from a list of 3,300 food items that were classified according to how processed they were.
Several well known risk factors for cancer, such as age, sex, educational level, family history of cancer, smoking status and physical activity levels, were taken into account.
Unhealthy diets and obesity were "associated with some cancers" said Dr Alison Tedstone, chief nutritionist at Public Health England.
Overall cancer risk according to quarters of proportion of ultra-processed food in diet. Image credits Fiolet et al BMJ
Researchers saw this new cancer link when they analyzed 24-hour dietary records of almost 105,000 adults in the NutriNet-Sante cohort, a general population group in France.
The authors of the report have suggested that the rapidly increasing consumption of ultra-processed foods "may drive an increasing burden of cancer in the next decades".
However, they determined the findings need to "be confirmed by other large-scale" studies and research was needed to establish what could be behind the link.
She added: "We know people are often nudged into eating more foods that are high in fat, sugar and salt by enticing price promotions, and we're calling for the Scottish Government to take action to regulate these. Ultra-processed sugary products were associated with an increased risk of breast cancer".
"Eating a balanced diet, avoiding junk food and maintaining a healthy weight are things we can all do to help stack the odds in our favour".
In their study, published in the British Medical Journal, the researchers say that ultra-processed food includes "mass produced packaged breads and buns; sweet or savoury packaged snacks; industrialised confectionery and desserts; sodas and sweetened drinks; meatballs, poultry and fish nuggets, and other reconstituted meat products". He said it chimed with the key concerns of his organisation's Real Bread Campaign and Sugar Smart initiative that "eating processed food may not be as good for you as eating unprocessed and minimally processed food".