Cancer Treatment and Antioxidants?
Is it advisable or not to supplement with antioxidant therapy during chemotherapy or radiation therapy?
This is a difficult question and there are heated differences of opinion, especially among cancer specialists (oncologists) who also practice integrative medicine.
One the one side, it is felt that taking antioxidants during cancer treatment could interfere with the way chemo and radiation work and diminish their benefits to the patient. This is because radiation and some chemotherapy agents work by generating free radicals and oxidative stress, which then kill rapidly dividing cancer cells. Since antioxidants scavenge free radicals, they might interfere with the therapeutic effects of these treatments.
The opposing argument is that oxidation supports the proliferation of malignant cells and may itself interfere with treatment. People who hold this view maintain that antioxidants may counter the harmful effects of oxidation in the malignant process and thereby increase the effects of drugs or radiation therapy to the benefit of the patient. Moreover, they note that some evidence suggests that antioxidant supplements offer patients protection from the toxic effects of therapy.
As things now stand, we need more research before we can definitive advise patients one way or another. In the absence of strong evidence, the advise is as:
For those being treated for a possible cure (meaning that their tumors have been removed and that the goal of chemotherapy or radiation is to destroy any remaining cancer cells): Don’t take antioxidant supplements (mainly Vitamin C, Vitamin E, Alpha Lipoic Acid, Coenzyme Q10, Melatonin) on the 3 days before, the day of, and the 3 days after chemotherapy. Otherwise, it is okay to take supplements.
For patients undergoing radiation therapy: no antioxidant supplements throughout the course of treatment.
For patients with advanced cancer who are being treated in order to prolong survival and relieve symptoms: it is okay to take antioxidant supplements. Because chemotherapy agents differ in their mode of action, it would be helpful to know whether the particular drugs being used work by an oxidative (free-radical-generating) mechanism. Ask the integrative physician treating you for that information.
There is no justification for patients undergoing chemotherapy or radiation therapy to avoid antioxidant-rich foods.