This webpage summarises some of the frequently asked questions about the Third Expert Report.
What is the Third Expert Report?
An independent panel of global experts has completed a decade-long review of all the evidence on diet, nutrition, physical activity, and cancer prevention and survival. This has culminated in the Third Expert Report, Diet, Nutrition, Physical Activity and Cancer: a Global Perspective, which provides a comprehensive analysis, using the most meticulous methods, of the worldwide body of evidence on preventing and surviving cancer through diet, nutrition and physical activity, and shares our latest global Cancer Prevention Recommendations.
All the evidence is accessible both by cancer site (17 in total) and exposure group (10 in total) – see the table of contents. The Third Expert Report also contains information on the cancer process, how the evidence was judged, survivors of breast and other cancers, the determinants of weight gain, overweight and obesity, changes since the 2007 Second Expert Report, and future research directions.
The Third Expert Report provides everyone with access to the most up-to-date and trustworthy information on how to reduce the risk of developing a preventable cancer.
Why is the Third Expert Report important?
Globally, 14.1 million people were diagnosed with cancer in 2012 and there were 8.2 million deaths from cancer. This global cancer burden is expected to increase to 21.7 million cases and 13 million deaths by 2030. The disease has a substantial emotional, social and economic impact. Yet around 40 per cent of cancer cases are preventable. The World Cancer Research Fund (WCRF) network has been researching the links between diet, nutrition, physical activity and cancer since 1983. The more we know about the risk factors for cancer, the more we can do to prevent it.
Who uses the Third Expert Report?
Everybody, from researchers to policymakers to individuals, will find something valuable in the report. It may be particularly useful to:
- researchers – when studying specific cancers and for guiding plans for future studies.
- medical and health professionals – by providing reliable, up-to-date Recommendations on preventing and surviving cancer to share with patients.
- policymakers – when setting public health goals and implementing policies that prioritise cancer prevention and help people to follow the Recommendations.
- civil society, including cancer organisations – when benchmarking progress and holding governments to account.
- media – by providing authoritative and trusted information on cancer prevention and a source of comment.
- people looking to reduce their risk of cancer or live well after a diagnosis – the Recommendations together constitute a blueprint for reducing cancer risk through changing dietary patterns, reducing alcohol consumption, increasing physical activity, and achieving and maintaining a healthy body weight, including after a diagnosis of cancer.
Is the Third Expert Report the same as the Continuous Update Project?
The Continuous Update Project (CUP) is a rigorous, systematic and ongoing programme to gather, analyse, judge and share global research on how diet, nutrition and physical activity affect cancer risk and survival, and to make recommendations. Scientific research from around the world is continually added to the CUP’s unique database, which is held and systematically reviewed by a team of scientists at Imperial College London. An independent multi-disciplinary panel of experts, the CUP Expert Panel, evaluates this evidence.
The Third Expert Report brings together the latest findings from the CUP, as well as updated Cancer Prevention Recommendations, and represents a landmark in the history of the WCRF network. Building on the groundbreaking achievements of the First and Second Expert Reports, published in 1997 and 2007 respectively, the latest report provides a comprehensive analysis of the worldwide body of evidence on preventing and surviving cancer through diet, nutrition and physical activity. It also presents the latest global Cancer Prevention Recommendations and ensures this valuable information is available to everyone.
Who wrote the Third Expert Report?
Over 140 people have been involved in creating the Third Expert Report. This includes:
- the Continuous Update Project Expert Panel, who judge and evaluate the evidence.
- the team at Imperial College London, who collate and systematically analyse the evidence.
- external peer reviewers.
- in-house scientists across the WCRF network.
Did WCRF carry out all the research in the Third Expert Report?
Scientific research from around the world is continually added to the Continuous Update Project’s (CUP) unique database, which is held and systematically reviewed by a team of scientists at Imperial College London. An independent multi-disciplinary panel of experts, the CUP Panel, carries out ongoing evaluations of this evidence and uses its findings to update the Cancer Prevention Recommendations.
The research, which is systematically reviewed, is generated by scientists and research groups from all over the world.
How is the evidence analysed for the Third Expert Report?
- A team at Imperial College London conducts systematic literature reviews (SLRs) – gathering and presenting the best-available, current, scientific evidence from around the world.
- The SLRs are peer reviewed by external peer reviewers.
- The International Agency for Research on Cancer provides expert reviews of the main biological mechanisms to support the epidemiological evidence.
- The CUP Expert Panel evaluates and interprets the evidence, making judgements on the likelihood that the exposures studied increase, decrease or have no effect on the risk of cancer.
- The Panel uses these judgements to make Recommendations for cancer prevention.
Why is there a chapter on energy balance and body fatness?
We know that greater body fatness increases the risk of 12 cancers. We also know that the prevalence of overweight and obesity is increasing worldwide. Therefore it is important to identify the drivers of weight gain, overweight and obesity as these are indirectly contributing to increased cancer risk. We investigated the diet and physical activity determinants of weight gain, overweight and obesity and presented the findings in Energy balance and body fatness. The evidence and findings helped to inform the Cancer Prevention Recommendations. The outcome of body weight is influenced by a complex web of interrelated factors, many of which are outside personal control; see also Public health and policy implications.
This chapter differs from the chapter on Body fatness and weight gain and the risk of cancer. In Body fatness and weight gain and the risk of cancer, the outcome of interest is cancer and the exposure being investigated is body fatness (including obesity) as marked by BMI and, where possible, waist circumference. In Energy balance and body fatness, the outcome of interest is weight gain, overweight and obesity and the exposures being investigated are a variety of diet and physical activity factors.
What is not in the Third Expert Report?
WCRF investigates the links between diet, nutrition, physical activity and cancer. Although we recognise that there are other established causes of cancer, our research does not focus on exposures such as smoking, ultra violet (UV) radiation exposure or certain infections.
The 17 cancer sites that are included in WCRF/AICR’s Third Expert Report are cancer sites where substantial evidence of links with diet, nutrition or physical activity exists. The 17 cancers included in the report account for 74% of the total global cancer incidence annually. Because evidence on other sites is accruing, others will be reviewed as part of the CUP future plans.
If we know that diet and cancer are linked, why do we need more research?
WCRF began highlighting the links between diet, nutrition, physical activity and cancer more than 25 years ago. Our vision is a world where no one develops a preventable cancer. But there are still gaps in our knowledge. For example, one focus of our research in forthcoming years is a more thorough understanding of the biological mechanisms by which diet, nutrition and physical activity affect the cancer process.
How can I access the whole Third Expert Report?
The report is over 2,000 pages, with over 10,000 additional pages of supporting evidence and, as such, is not available in print. You can download the full report as a PDF or each section individually. Printed copies of the Summary are available on request.
What has changed since the Second Expert Report?
The consistency in our Cancer Prevention Recommendations since 2007 means that people can be confident in the evidence base and in the advice given to policymakers, the scientific community, health professionals and the public. However, advances in the science have enabled two key differences between the 2007 and 2018 reports:
- An important shift in emphasis to a more holistic focus, recognising that, rather than specific foods affecting cancer risk, different patterns of diet and physical activity combine to create a body that is more or less susceptible to developing cancer. Therefore, there is most to be gained from our Cancer Prevention Recommendations by treating them as an integrated pattern of behaviours that can be considered as a single overarching ‘package’ or way of living, rather than as isolated recommendations.
- There has been an increase in the overall amount of evidence since 2007. This has enabled the Expert Panel to fine-tune its approach to assessing and interpreting evidence.
More detail can be found on the Changes since the Second Expert Report webpage.