As more people across the globe continue to adopt a ‘Western’ diet and lifestyle, the number of new cases of cancer is expected to rise by 58 per cent to 24 million globally by 2035.
This is according to a new report from World Cancer Research Fund (WCRF), released this week at the European Congress on Obesity in Austria.
The report – Diet, Nutrition, Physical Activity and Cancer: a Global Perspective – also shows that being overweight or obese is a cause of at least 12 cancers, five more than the WCRF findings a decade ago.
These cancers include cancer of the liver, ovary, advanced prostate, stomach (cardia), mouth and throat, bowel, breast (post-menopause), gallbladder, kidney, oesophagus, pancreas and womb (endometrium).
“However, it appears increasingly unlikely that specific foods, nutrients or other components of foods are themselves important singular factors in causing or protecting against cancer."
"Diet, nutrition and physical activity are essential aspects of human existence," the report reads. "Imbalanced and inappropriate levels of these factors can disturb normal homeostasis and reduce resilience to external challenges. This may manifest in many ways, for instance as susceptibility to infections, to cardiometabolic disease or to cancer."
In the report, the international non-profit association acknowledges that previous research has identified various foods (for example, processed meat) or components of food (like dietary fibre) that may increase or decrease the risk of cancer.
“However, it appears increasingly unlikely that specific foods, nutrients or other components of foods are themselves important singular factors in causing or protecting against cancer,” the report says.
“Rather, different patterns of diet and physical activity combine to create a metabolic state that is more, or less, conducive to cancer.”
Chair of Cancer Council Australia’s Nutrition and Physical Activity Committee, Steve Pratt, says he supports the WCRF’s recent statement.
“This latest WCRF report reinforces the importance of healthy eating, physical activity, maintaining a healthy weight and reducing alcohol intake to reduce cancer risk,” explains Pratt.
The WCRF estimates that around one in six deaths each year, worldwide, are currently caused by cancer. Research commissioned by Cancer Council and released in 2015 shows that at least one in three Australian cancer cases are preventable.
Pratt explains that while smoking continues to be Australia’s biggest preventable cause of cancer, it’s estimated that each year 7000 new cancer cases a year are attributable to diet. Around 3,900 cases relate to people being obese and overweight, 3,200 are caused by excess alcohol consumption and 1,800 are caused by physical inactivity.
“While there is no one food or diet that will prevent cancer – this report is a powerful reminder that we can all make simple changes to our lifestyle to help reduce our risk,” says Pratt.
“We hope more Australians hear the message and decide to take action.”
The blueprint for cancer prevention
The report also includes updated cancer prevention recommendations, advising diet and lifestyle actions that will help most people to minimise their risk of developing cancer.
However, the advice comes with a caveat. “While following each individual recommendation is expected to offer cancer protection benefit, the most benefit is to be gained by treating them as an integrated pattern of behaviours relating to diet and physical activity, and other factors, that can be considered as a single overarching ‘package’ or way of life,” the report reads.
Here are eight of the organisation's cancer prevention recommendations.
1. Keep your weight within the healthy range and avoid weight gain in adult life.
2. Be physically active as part of everyday life – walk more and sit less.
3. Make wholegrains, vegetables, fruit, and pulses (legumes) such as beans and lentils a major part of your usual daily diet.
4. Limit consumption of ‘fast foods’ and other processed foods high in fat, starches or sugars. By limiting these foods helps control calorie intake and maintain a healthy weight.
5. Eat no more than moderate amounts of red meat, such as beef, pork and lamb. Eat little, if any, processed meat.
6. Limit consumption of sugar-sweetened drinks. Drink mostly water and unsweetened drinks.
7. Limit alcohol consumption. For cancer prevention, it’s best not to drink alcohol.
8. Do not use supplements for cancer prevention. Aim to meet nutritional needs through diet alone.
The report states that in some situations – for example, in preparation for pregnancy or when diet is inadequate for some reason – supplements may be advisable. “But for cancer prevention, we are confident that for most people eating the right food and drink is more likely to protect against cancer than taking dietary supplements.”