Martin Wiseman

European Code against Cancer 4th Edition: Diet and cancer

Lifestyle factors, including diet, have long been recognised as potentially important determinants of cancer risk. In addition to the significant role diet plays in affecting body fatness, a risk factor for several cancers, experimental studies have indicated that diet may influence the cancer process in several ways. Prospective studies have shown that dietary patterns characterised by higher intakes of fruits, vegetables, and whole-grain foods, and lower intakes of red and processed meats and salt, are related to reduced risks of death and cancer, and that a healthy diet can improve overall survival after diagnosis of breast and colorectal cancers. There is evidence that high intakes of fruit and vegetables may reduce the risk of cancers of the aerodigestive tract, and the evidence that dietary fibre protects against colorectal cancer is convincing. Red and processed meats increase the risk of colorectal cancer. Diets rich in high-calorie foods, such as fatty and sugary foods, may lead to increased calorie intake, thereby promoting obesity and leading to an increased risk of cancer. There is some evidence that sugary drinks are related to an increased risk of pancreatic cancer. Taking this evidence into account, the 4th edition of the European Code against Cancer recommends that people have a healthy diet to reduce their risk of cancer: they should eat plenty of whole grains, pulses, vegetables and fruits; limit high-calorie foods (foods high in sugar or fat); avoid sugary drinks and processed meat; and limit red meat and foods high in salt.

European Code against Cancer 4th Edition: Physical activity and cancer.

Physical activity is a complex, multidimensional behavior, the precise measurement of which is challenging in free-living individuals. Nonetheless, representative survey data show that 35% of the European adult population is physically inactive. Inadequate levels of physical activity are disconcerting given substantial epidemiologic evidence showing that physical activity is associated with decreased risks of colon, endometrial, and breast cancers. For example, insufficient physical activity levels are thought to cause 9% of breast cancer cases and 10% of colon cancer cases in Europe. By comparison, the evidence for a beneficial effect of physical activity is less consistent for cancers of the lung, pancreas, ovary, prostate, kidney, and stomach. The biologic pathways underlying the association between physical activity and cancer risk are incompletely defined, but potential etiologic pathways include insulin resistance, growth factors, adipocytokines, steroid hormones, and immune function. In recent years, sedentary behavior has emerged as a potential independent determinant of cancer risk. In cancer survivors, physical activity has shown positive effects on body composition, physical fitness, quality of life, anxiety, and self-esteem. Physical activity may also carry benefits regarding cancer survival, but more evidence linking increased physical activity to prolonged cancer survival is needed. Future studies using new technologies - such as accelerometers and e-tools - will contribute to improved assessments of physical activity. Such advancements in physical activity measurement will help clarify the relationship between physical activity and cancer risk and survival. Taking the overall existing evidence into account, the fourth edition of the European Code against Cancer recommends that people be physically active in everyday life and limit the time spent sitting.

European Code against Cancer 4th Edition: 12 ways to reduce your cancer risk

This overview describes the principles of the 4th edition of the European Code against Cancer and provides an introduction to the 12 recommendations to reduce cancer risk. Among the 504.6 million inhabitants of the member states of the European Union (EU28), there are annually 2.64 million new cancer cases and 1.28 million deaths from cancer. It is estimated that this cancer burden could be reduced by up to one half if scientific knowledge on causes of cancer could be translated into successful prevention. The Code is a preventive tool aimed to reduce the cancer burden by informing people how to avoid or reduce carcinogenic exposures, adopt behaviours to reduce the cancer risk, or to participate in organised intervention programmes. The Code should also form a base to guide national health policies in cancer prevention. The 12 recommendations are: not smoking or using other tobacco products; avoiding second-hand smoke; being a healthy body weight; encouraging physical activity; having a healthy diet; limiting alcohol consumption, with not drinking alcohol being better for cancer prevention; avoiding too much exposure to ultraviolet radiation; avoiding cancer-causing agents at the workplace; reducing exposure to high levels of radon; encouraging breastfeeding; limiting the use of hormone replacement therapy; participating in organised vaccination programmes against hepatitis B for newborns and human papillomavirus for girls; and participating in organised screening programmes for bowel cancer, breast cancer, and cervical cancer.

Development of a scoring system to judge the scientific quality of information from case-control and cohort studies of nutrition and disease

A scoring system was developed to help judge the scientific quality of observational epidemiologic studies linking diet with risk of cancer. The scoring system was developed from key headings used in developing research protocols and included questions under headings: three for case-control studies (dietary assessment, recruitment of subjects, and analysis) and four for cohort studies (dietary assessment, definition of cohort, ascertainment, and analysis). Points were awarded for questions in each section, and a total score was derived. Interobserver variation was assessed for five case-controls and five cohort studies for 13 observers: 1 observer repeated the assessment of each paper. Absolute scores and ranking within observer were assessed. There was good agreement between observers in the ranking of studies. Papers that scored higher presented sufficient detail to enable the questions in the scoring system to be answered more easily. For some studies, the information required was either not collected or, if it was collected, not presented. In either case, the frequent lack of information available to judge papers raises questions about the editorial policy and review process of journals publishing dietary studies as much as it does about the scoring system. Applying the scoring system to a review of meat and cancer risk suggested that, taking the score into account, from what seemed like a large literature, there were relatively few studies that scored well (defined as a score > 65%), but these studies tended to provide more consistent information.

Obesity in breast cancer--what is the risk factor?

Environmental factors influence breast cancer incidence and progression. High body mass index (BMI) is associated with increased risk of post-menopausal breast cancer and with poorer outcome in those with a history of breast cancer. High BMI is generally interpreted as excess adiposity (overweight or obesity) and the World Cancer Research Fund judged that the associations between BMI and incidence of breast cancer were due to body fatness. Although BMI is the most common measure used to characterise body composition, it cannot distinguish lean mass from fat mass, or characterise body fat distribution, and so individuals with the same BMI can have different body composition. In particular, the relation between BMI and lean or fat mass may differ between people with or without disease. The question therefore arises as to what aspect or aspects of body composition are causally linked to the poorer outcome of breast cancer patients with high BMI. This question is not addressed in the literature. Most studies have used BMI, without discussion of its shortcomings as a marker of body composition, leading to potentially important misinterpretation. In this article we review the different measurements used to characterise body composition in the literature, and how they relate to breast cancer risk and prognosis. Further research is required to better characterise the relation of body composition to breast cancer.

Energy balance and obesity: what are the main drivers?

PurposeThe aim of this paper is to review the evidence of the association between energy balance and obesity.MethodsIn December 2015, the International Agency for Research on Cancer (IARC), Lyon, France convened a Working Group of international experts to review the evidence regarding energy balance and obesity, with a focus on Low and Middle Income Countries (LMIC).ResultsThe global epidemic of obesity and the double burden, in LMICs, of malnutrition (coexistence of undernutrition and overnutrition) are both related to poor quality diet and unbalanced energy intake. Dietary patterns consistent with a traditional Mediterranean diet and other measures of diet quality can contribute to long-term weight control. Limiting consumption of sugar-sweetened beverages has a particularly important role in weight control. Genetic factors alone cannot explain the global epidemic of obesity. However, genetic, epigenetic factors and the microbiota could influence individual responses to diet and physical activity.ConclusionEnergy intake that exceeds energy expenditure is the main driver of weight gain. The quality of the diet may exert its effect on energy balance through complex hormonal and neurological pathways that influence satiety and possibly through other mechanisms. The food environment, marketing of unhealthy foods and urbanization, and reduction in sedentary behaviors and physical activity play important roles. Most of the evidence comes from High Income Countries and more research is needed in LMICs.

Recent Evidence for Colorectal Cancer Prevention Through Healthy Food, Nutrition, and Physical Activity: Implications for Recommendations

The aim of this paper is to present results from the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Continuous Update Project on colorectal cancer and food, nutrition, and physical activity, an updated systematic literature review on evidence forming part of the 2007 WCRF/AICR Second Expert Report. Convincing evidence indicates that physical activity protects against colon cancer and that foods containing dietary fiber protect against colorectal cancer. Consumption of red meat and processed meat, ethanol from alcoholic drinks (by men and probably by women), as well as body fatness and abdominal fatness and the factors that lead to greater adult-attained height or its consequences are convincing causes of colorectal cancer. Consumption of garlic, milk, and calcium probably protects against this cancer. The updated evidence shows that food, nutrition, and physical activity have an important role in the causation and prevention of colorectal cancer.

European Code against Cancer 4th Edition: Process of reviewing the scientific evidence and revising the recommendations

The European Code Against Cancer is a set of recommendations to give advice on cancer prevention. Its 4th edition is an update of the 3rd edition, from 2003. Working Groups of independent experts from different fields of cancer prevention were appointed to review the recommendations, supported by a Literature Group to provide scientific and technical support in the assessment of the scientific evidence, through systematic reviews of the literature. Common procedures were developed to guide the experts in identifying, retrieving, assessing, interpreting and summarizing the scientific evidence in order to revise the recommendations. The Code strictly followed the concept of providing advice to European Union citizens based on the current best available science. The advice, if followed, would be expected to reduce cancer risk, referring both to avoiding or reducing exposure to carcinogenic agents or changing behaviour related to cancer risk and to participating in medical interventions able to avert specific cancers or their consequences. The information sources and procedures for the review of the scientific evidence are described here in detail. The 12 recommendations of the 4th edition of the European Code Against Cancer were ultimately approved by a Scientific Committee of leading European cancer and public health experts.

The use and interpretation of anthropometric measures in cancer epidemiology: A perspective from the World Cancer Research Fund International Continuous Update Project.

Anthropometric measures relating to body size, weight and composition are increasingly being associated with cancer risk and progression. Whilst practical in epidemiologic research, where population‐level associations with disease are revealed, it is important to be aware that such measures are imperfect markers of the internal physiological processes that are the actual correlates of cancer development. Body mass index (BMI), the most commonly used marker for adiposity, may mask differences between lean and adipose tissue, or fat distribution, which varies across individuals, ethnicities, and stage in the lifespan. Other measures, such as weight gain in adulthood, waist circumference and waist‐to‐hip ratio, contribute information on adipose tissue distribution and insulin sensitivity. Single anthropometric measures do not capture maturational events, including the presence of critical windows of susceptibility (i.e., age of menarche and menopause), which presents a challenge in epidemiologic work. Integration of experimental research on underlying dynamic genetic, hormonal, and other non‐nutritional mechanisms is necessary for a confident conclusion of the overall evidence in cancer development and progression. This article discusses the challenges confronted in evaluating and interpreting the current evidence linking anthropometric factors and cancer risk as a basis for issuing recommendations for cancer prevention.

Tackling the obesity crisis: how do we ‘measure up’?

In early 2013, the Academy of Medical Royal Colleges (AoMRC) published the latest of several reports from various bodies over decades addressing aspects of the rising prevalence of obesity in the UK.1 Their report ‘Measuring Up’ made 10 recommendations targeted at the healthcare professions, at the obesogenic environment and towards making healthy choices the easy choices (box 1). The report made no claim to originality in describing the scale of the problem or in its selection of recommendations, derived from a wide ranging consultative process. It was, however, unusual in declaring the report to be the start of a campaign, and in its wide franchise in representing all the Medical Royal Colleges, and so indirectly virtually all medical practitioners in the UK. It is worth examining the contribution this particular report might make as part of its called-for campaign to solving what has up to now been a seemingly intractable problem. Box 1 ### Taken from ‘Measuring Up’ Action by the healthcare professions 1. Education and training programmes for healthcare professionals: Royal Colleges, Faculties and other professional clinical bodies should promote targeted education and training programmes within the next 2 years for healthcare professionals in both primary and secondary care to ensure ‘making every contact count’ becomes a reality, particularly for those who have most influence on patient behaviour 2. Weight management services: The departments of health in the four nations should together invest at least £100 m in each of the next three financial years to extend and increase provision of weight management services across the country, to mirror the provision of smoking cessation services. This should include both early intervention programmes and greater provision for severe and complicated obesity, including bariatric surgery. Adjustments could then be made to the Quality and Outcomes Framework, providing incentives for General Practitioners to refer patients to …