RISK FACTORS
Figure 1: WCRF/AICR Recommendations for cancer prevention
alcohol)7. In particular, unhealthy diets –
especially the excessive consumption of
1. Be as lean as possible without becoming underweight. calories, salt, saturated fat and sugar –
2. Be physically active for at least 30 min every day.
account for at least 40% of all deaths
3. Avoid sugary drinks and limit consumption of energy-dense foods (particularly
from NCDs, and approximately one-
processed foods high in added sugar, low in fibre, or high in fat).
4. Eat more of a variety of vegetables, fruits, whole grains, and pulses. quarter of all deaths globally8. Based on a
5. Limit consumption of red meats and avoid processed meats. systematic review of other authoritative
6. If consumed at all, limit alcoholic drinks to 2 per day for men and 1 per day for reports, the Second Expert Report
women. concluded that the recommendations for
7. Limit consumption of salty foods and foods processed with salt (sodium).
cancer prevention would also prevent the
8. Do not use supplements to protect against cancer.**
other main NCDs.
9. It is best for mothers to breastfeed exclusively for up to 6 months and then add other
liquids and foods.
10. After treatment, cancer survivors should follow the Recommendations for Cancer The challenge of the “double
Prevention. burden of disease”
In LIC, nutritional deficiencies and
** The evidence on high-dose nutrient supplements is conflicting and has been shown to both increase
and decrease risk of cancer. The studies that demonstrate such effects do not relate to widespread use nutrition-related infectious diseases co-
among the general population, in whom the balance of risks and benefits cannot confidently be
predicted. Increasing consumption of relevant nutrients through the usual diet is preferred. exist with obesity and NCDs, sometimes
within the same communities and even
3
cohort studies (case-control studies are included if there are within families ; this is known as the “double burden of disease.”
few studies), with no date limitation. The exposures relate to The interaction between under- and over-nutrition is also an
food, nutrition, physical activity or anthropometric measures independent driver of the NCD epidemic in LMIC (intake of
and outcomes include cancer incidence, mortality or both insufficient and excess calories)9. This emerging challenge
recurrence. The database of published journal articles is makes it particularly difficult for governments to prioritize
updated on a rolling basis from which at any point in time, the action. Ongoing food security risks for the most vulnerable
most current review of scientific data (including meta-analyses groups are now compounded by a dietary shift in LMIC, from
where appropriate) can be performed. By the end of 2011, the traditional diets to less healthy western diets with increasingly
database contained information on about 1,800 journal papers industrialized food systems, heavily processed foods and
from cohort studies on cancers of the breast, colorectum, increasing urbanization10. An emerging priority for LMIC and
prostate and pancreas. international health and development agencies is to ensure
A summary of the conclusions from the 2007 WCRF/AICR that strengthened policy action and interventions address the
Second Expert Report, based on strong (convincingly or whole spectrum of nutrition and diet-related risk factors. The
probably causal) evidence and supported by recent updated recent adoption of the WHO implementation plan on maternal,
evidence from the CUP, is presented in Table 1. Details of the infant and child nutrition is a positive development in this
preventable fraction for each cancer site according to each field11.
determinant in different countries are presented in our 2009 The globalization of markets has led to a rapid increase in the
Policy Report3. availability of mass-produced, processed foods with long shelf
lives. This has resulted in the sharp rise in the consumption of
Nutritional challenges affect other noncommunicable soft drinks and processed foods high in fat, sugar and salt
diseases (energy-dense, nutrient-poor) that is contributing to the
In addition to cancer, rates of other noncommunicable diseases increase risk of NCDs12.
(NCDs) also continue to rise in LMIC, affecting the poorest and Globally, consumption industries – especially soft drinks and
most vulnerable populations. LMIC account for nearly 80% of processed foods as well as tobacco, alcohol – are increasingly
NCD deaths worldwide, which includes cancer, cardiovascular targeting developing countries’ markets for expansion13. In
diseases, respiratory diseases and diabetes5. The 2002 alone, sales of processed foods in LMIC grew by around
consequences of the NCD epidemic include major adverse 29%, compared to 7% in upper to MIC14. Unhealthy food and
social, economic and health effects, a key challenge on the drinks consumption in LMIC is growing at a faster pace than
6
global health agenda . NCDs are largely preventable by previously experienced in HIC15. Multinational companies have
eliminating shared modifiable behavioural risk factors (tobacco penetrated the food system in LMIC and although they have
use, unhealthy diet, physical inactivity and the harmful use of committed to remove transfats and reduce levels of salt, sugar,
CANCER CONTROL 2013 45