Not a day goes by, it seems, without a news report extolling the cancer-fighting benefits of one kind of food or another.
But are these foods as beneficial as they seem? Are some better at reducing the risk of cancer than others? And where can you go for accurate information on this subject?
While the answers to these and other questions are not always as clear-cut as we would like, there are some basic facts that can help build the foundation for informed decision-making about what foods may help you reduce your risk for certain types of cancer.
The first thing to understand about the link between diet and cancer is that no specific food by itself will do the trick. The nutrients that help combat cancer are found in many different types of foods, and you need a variety of nutrients to protect yourself against different types of cancer. In fact, there is evidence to suggest that rather than diet alone, the best deterrent against cancer is healthy living - the combination of diet, regular exercise and weight control.
This point is underscored in the second report published in 2007 by the American Institute for Cancer Research (AICR) and the World Cancer Research Fund (WCRF). Entitled "Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective," the report is a review of cancer research in this area. The report is virtual, which means it is regularly updated as new research is published and reviewed, and can be found at www.dietandcancerreport.org and the updates at www.wcrf.org.
The WCRF and AICR estimate that in the United States, eating a nutritious diet, being physically active and controlling weight may prevent:
- 38 per cent of breast cancers
- 45 per cent of colorectal cancers
- 36 per cent of lung cancers
- 39 per cent of pancreatic cancers
- 47 per cent of stomach cancers
- 69 per cent of esophageal cancers
- 63 per cent of cancers of the mouth, pharynx or larynx
- 70 per cent of endometrial cancers
- 24 per cent of kidney cancers
- 21 per cent of gallbladder cancers
- 15 per cent of liver cancers
- 11 per cent of prostate cancers
Keep in mind that these numbers refer to the effect on reducing cancer in the population as a whole, as opposed to individuals. Still, the evidence is clear: rates of cancer are lower for people who lead a healthy lifestyle.
So, what role do foods play in all this?
Researchers have found that certain foods that contain phytochemicals and antioxidants help fight cancer and other chronic diseases. Phytochemicals are natural compounds found in fruits, vegetables, legumes, whole grains, nuts, seeds, herbs and spices. Antioxidants, which belong to the phytochemical family, destroy free radicals (harmful compounds that damage cells) in the body. Many vitamins found in vegetables and fruit act as diseasefighting antioxidants and work as a team with the other substances found in foods.
As this chart illustrates, different foods contain specific nutrients that are associated with reduced risk of certain cancers. For example, if you want to reduce your risk of prostate cancer, then make sure you consume foods containing phytochemicals, such as lycopene, which can be found in tomatoes (tomato juice, tomato sauce), watermelon, guava, papaya, apricots and pink grapefruit, or antioxidants, such as selenium, which can be found in rice, wheat, Brazil nuts, chicken and fish.
It is, of course, important to remember that there are no guarantees against cancer. Still, the research clearly suggests that combining a healthy diet with regular exercise and weight control can have a positive impact. The overall message from AICR is: It's never too early or too late to make changes that can help prevent cancer. To learn more, visit their website.
Beth Szuck is a registered dietitian with the Winnipeg Health Region.