Does eating ultra-processed food increase the risk of cancer?

Prof. Millett is investigating how eating ultra-processed foods (such as biscuits, crisps, and cakes) affects the risk of developing, and dying of, cancer

  • Topic: Combination of cancers
  • Institution: Imperial College London
  • Country: United Kingdom
  • Status: Ongoing
Researcher: Chris Millett
  • Grant awarded: November 2020

Sales of ultra-processed foods are growing globally. While their consumption has been linked to an increased risk of obesity, diabetes and heart disease we know very little about the associated risks of developing cancer. WCRF funding will permit us to perform the most comprehensive evaluation on the consumption of ultra-processed foods in relation to risk of cancer, cardio-metabolic diseases and death using two large-scale European cohort studies.

– Chris Millett


The term ‘ultra-processed’ food (UPF) has become widely used, not only because such foods now make up a huge part of our diet (some 25%–60% of daily energy intake), but also because many researchers believe UPFs are responsible for rising obesity levels around the globe.

UPFs are usually defined as industrial formulations of foods and drinks that contain little or no whole food, but chemical additives not used in culinary preparations. Growing evidence has linked UPF consumption to various health issues, including increased risk of obesity, hypertension, diabetes and heart disease. Yet robust evidence is lacking on any association between UPFs and cancer, except for one study from France that demonstrated an increased risk for total and breast cancer in people eating higher levels of UPFs.

Aims and objectives

We aim to perform the first and most comprehensive evaluation on UPFs in relation to risk of cancer, cardio-metabolic diseases and death. As part of this, we will estimate the number of excess cancer cases potentially due to UPF consumption between 2000-2030, and model different scenarios including impact of replacing UPFs with fresh or minimally-processed foods.

How it will be done

This project will be use data collected in two large studies: The UK Biobank (N~211,000) and the European Prospective Investigation into Cancer and Nutrition (EPIC) study (N~500,000). These studies were designed to investigate the role of diet, metabolism, lifestyle, and environmental factors on the development of cancer and other chronic diseases. An individual’s diet was assessed using questionnaire, and all food items have been classified into one of four groups:

  • unprocessed or minimally processed foods (e.g. fruits; grains, flours and pasta);
  • processed culinary ingredients (e.g. table sugar, oils, salt);
  • processed foods (e.g. cheese); and
  • UPFs (e.g. soft drinks, savoury packaged snacks, reconstituted meat products).

New cancer cases and deaths are identified through cancer and death registries. Cardio-metabolic events are ascertained via a combination of self-reported and routinely collected data.

Associations between UPF, cancer and deaths will be investigated. We will apply standard statistical analysis, taking into account the presence of competing events (e.g. individuals dying of cardiovascular disease before developing cancer). Estimated projections of cancer burden in Europe up to year 2030 will be performed including the impact of replacing UPFs with fresh or minimally-processed foods on cancer risk and mortality.

Potential impact

The data generated will add more definitive evidence on the link between UPFs and the risk of developing and dying from cancer and will identify potential strategies for preventative interventions. Our project will also generate estimates for the number of cases of cancer and related mortality based on different levels of UPF consumption. This will provide important information to strengthen policy action.

Grant publications

Media coverage

The nearly 20% rise in ovarian cancer for UPF-heavy diets was widely picked up in international media when the paper was published in March 2023. Read more about how the story was covered.