Some people choose to use complementary and alternative therapies (CAM) during cancer treatment. These therapies may help promote health, improve quality of life or support healing.
However, some CAM therapies can interfere with chemotherapy or radiation therapy. Because of this risk, patients should talk with their health care providers about any CAM therapies they are using or considering.
Natural Medicines Database
BC Cancer subscribes to the Natural Medicines Database, an independent and research-based resource. Cancer patients who are interested in special diets, herbs or supplements can ask for information at any BC Cancer library. Library staff can help patients access reliable, evidence-based information from this database.
BC Cancer has shared evidence-based information on complementary and alternative medicine since 1987, when it first published Unproven Methods of Cancer Treatment: A manual for patients. Later editions were released as the Unconventional Cancer Therapies Manual, with the final edition published in 2000.
Since then, many reliable, evidence-based websites on CAM therapies have become available. BC Cancer lists trusted online resources on the
BC Cancer Library Complementary and Alternative Medicine (CAM) Pathfinder. Another trusted source for information on herbs and supplements is MedlinePlus.
The Complementary and Alternative Medicine Education and Outcomes Research Program (CAMEO) is a joint research initiative between the UBC School of Nursing and BC Cancer. The program focuses on turning CAM research into clear, easy-to-use information for patients and health care professionals. While CAMEO does not offer individual consultations, many of its cancer-related CAM resources remain available on the
CAMEO web pages.
While receiving chemotherapy, radiation therapy or surgery, BC Cancer does not recommend the use of natural health products.
Natural health products include vitamins, minerals, herbs and supplements that people take regularly in addition to food. Some people take these products in amounts higher than what they would normally get from their diet.
A standard-strength multivitamin and mineral supplement is acceptable. Choose a product that matches your age group. The supplement should contain small amounts of many nutrients. High-dose supplements are not recommended.
Doctors cannot predict how natural health products will affect cancer treatment. Chemotherapy and radiation therapy work in complex ways that are not fully understood. These treatments aim to damage cancer cells while protecting healthy cells.
Natural health products may interfere with this balance. They could reduce how well treatment works or increase side effects.
Some natural health products also affect how your body processes chemotherapy drugs. For example, St. John's Wort can reduce the amount of certain chemotherapy drugs in the blood by about half. This may lower the number of cancer cells destroyed.
Doctors need strong scientific evidence to know whether a natural health product is safe during cancer treatment. At this time, there are few studies that compare people who use natural health products with those who do not. Because of this, the safety and benefit of using these products during cancer treatment are unknown.
Most foods do not need to be restricted during cancer treatment. Your cancer care team will tell you if there are foods you should avoid. For diet-related questions, speak with a registered dietitian at your cancer treatment centre.
These recommendations are meant to guide patients on the safe use of natural health products. This topic remains controversial because there is limited scientific evidence available.
If you have questions, talk with your doctor, pharmacist, nurse or dietitian. You can also find more information through the
BC Cancer Library.
Weiger WA, Smith M, Boon H, et al. 'Advising patients who seek complementary and alternative medical therapies for cancer'. Ann Intern Med 2002;137:889-903.
