A closer look at the recent research on ultra processed foods


Today’s headlines highlight recent research[1] in which ultra-processed foods have been ‘linked to cancer.’

The study included 104,980 French adults who reported on their dietary intake and whether they subsequently developed cancer in the following 5 years. Ultra-processed food in this study  included mass produced packaged bread, sweet or savoury packaged snacks, sweets, fizzy drinks, meat and  fish products, ready meals, instant soups or sauces and desserts. These foods accounted for between 10 and 25% of the food eaten.

processed foods

People eating more of these foods developed more cancers, including breast cancer. For every extra 10% of daily food intake from these foods there was a 12% greater chance of developing any cancer and 11% greater chance of developing breast cancer after the menopause. Breast cancer in particular seemed to be strongly linked to the sugary products.

So should we stop buying processed foods?

The research highlights a potential issue with ultra-processed food, however is hard to pin point cancer to these foods.

Firstly, the ultra-processed food eaters tended to be less healthy overall and more likely to be smokers and sedentary and have higher energy intakes and were likely to be gaining weight which are all risk factors for breast cancer.

The ultra-processed foods include such a large range of foods which could be specifically linked to cancer but the study does not tell us if which if any have a role. Is it the high sugar or high fat foods, specific food additives or the plastic packaging? A key factor for ultra-processed food eaters is their low intake of unprocessed foods and essential nutrients such as fibre and plant-based nutrients, and most likely a limited unhealthy gut flora which is likely to be driving ill health and cancer risk.

Until we have the answers to these questions about processed food the best advice is to follow a healthy Mediterranean-style diet which includes a wide variety of foods including wholegrains, fruit and vegetables, lean protein foods, nuts and oils, and which limits high sugar high energy foods. These foods are part of our protection to developing cancer.

not processed foods


Researchers at Prevent Breast Cancer carry out studies into how diet and lifestyle factors affect the risk of developing breast cancer. Click here to learn more about this work.

[1] ‘Consumption of ultra-processed foods and cancer risk: results from NutriNet-Santé prospective cohort’

BMJ 2018; 360  doi: (Published 14 February 2018)