In 1997, the American Institute for Cancer Research and the World Cancer Research Fund (AICR/WCRF) concluded that cancer is preventable. In their 670-page report, Food, Nutrition and the Prevention of Cancer: a Global Perspective, they stated that the chief causes of cancer were the use of tobacco and inappropriate diets.
Controversially, the report concluded that 30-40 per cent of all cases of cancer are preventable by feasible and appropriate diets, physical activity and maintenance of appropriate body weight. On a global scale and at current rates, this means preventing three to four million cases of cancer every year.
The report highlighted 14 dietary strategies to prevent cancer:
* The type of food you eat is important. Choose a predominantly plant-based diet rich in a variety of vegetables and fruits, pulses (legumes) and minimally processed, starchy staple foods.
* Maintain your body weight. Avoid being underweight or overweight and limit weight gain during adulthood to less than 5 kg (11 lb).
* Stay active. If your job is largely sedentary, take an hour's brisk walk or similar exercise daily, and exercise vigorously for at least one hour a week.
* Eat more vegetables and fruits. Aim for 400-800 g (15-30 oz), or five or more portions (servings) a day of a variety of vegetables and fruits all year round.
* Other plant foods are also important. Eat 600-800 g (20-30 oz) or more than seven portions (servings) a day of a variety of cereals or grains, pulses (legumes), roots, tubers and plantain. Choose minimally processed foods whenever possible and limit consumption of refined sugar.
* Alcohol consumption is not recommended. If consumed at all, limit alcoholic drinks to less than two drinks a day for men and one for women.
* Be choosy about meat. If eaten at all, limit intake of red meat to less than 80 g (3 oz) daily. It is preferable to choose fish, poultry or meat from non-domesticated animals instead of red meat.
* Limit consumption of fatty foods, particularly those of animal origin. Choose modest amounts of appropriate vegetable oils.
* Limit consumption of salted foods, and use of cooking and table salt. Instead, consider using herbs and spices to season foods.
* Store perishable food carefully to minimise fungal contamination. Use refrigeration and other appropriate methods, and do not eat food which, as a result of prolonged storage at ambient temperatures, is liable to contamination with fungal toxins.
* Watch out for additives and residues. While levels of synthetic additives and pesticide residues are officially considered 'low' in our foods, err on the side of caution whenever you can. Prepare your foods yourself and eat organic as much as possible.
* Cook with low temperatures. Do not eat charred food. Meat- and fish-eaters should avoid burning the meat juices. Consume meat and fish grilled (broiled) over a direct flame; eat cured and smoked meats only occasionally.
* Take your supplements. While officials still deny the usefulness of supplements in the fight against cancer, increasingly nutrient-poor soils mean that even when you eat a 'balanced' diet, you may not be getting all you need. A good-quality multivitamin/mineral supplement is now a daily minimum requirement.
* Don't smoke or chew tobacco - it's undeniably bad for you.