Antioxidants during chemotherapy

Katrina Claghorn, MS, RD
Last Modified: March 31, 2002

Dear OncoLink "Ask The Experts,"

My wife is set to begin chemotherapy treatment. We are working with a nutritional advisor. We will be following his 10-step program, which advocates exercise, low fat high fiber diet, meditation, and vitamin and mineral supplements. He is advocating continuing to use the vitamins during chemo because there is no study that shows an anti- affect on the treatment. While there are many studies supporting the use of antioxidants. What are you thoughts on this difficult decision we have to make? Should my wife continue on the vitamin regimen during chemo or not?

Thank you for your thoughts in advance.

Katrina Claghorn, MS, RD, registered dietitian at the Abramson Cancer Center of the University of Pennsylvania, responds:

Actually there are studies showing that some antioxidants can interfere with chemotherapy. There have also been some studies showing benefit from combining antioxidants and chemotherapy. However, the problem is that we are still trying to figure which antioxidants and which chemotherapies can be combined. So far there isn't enough information to substantiate either claim. Your wife's medical team will develop a treatment regimen based on sound science and they will always lean towards the side of caution. The regimens they use have been tested and the potential problems identified. The effect of using antioxidants with these treatments have not received the same scientific scrutiny, which is why there is hesitancy to combine them outside of clinical trials. If she is receiving radiation therapy, she should hold off on using antioxidants. Radiation therapy kills cancer cells by generating oxidants. If high doses of antioxidants are present, this could theoretically decrease the effectiveness of radiation treatments.

Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999; 13:1003-1012.