CancerFlavonoids (Soy)MelatoninVitamins

Is it risky taking antioxidants during cancer treatment?

Researchers from Columbia University in New York City looked at the evidence in breast cancer patients.

First, the details.

  • They found 22 articles worth reviewing.
  • Antioxidants included vitamin C, vitamin E, antioxidant combinations, multivitamins, glutamine, glutathione, melatonin, or soy isoflavones.
  • Each antioxidant was given during chemotherapy, radiation therapy, and/or hormonal therapy for breast cancer.

And, the results.

  • There was no increased risk for negative effects of individual antioxidants on toxicity, tumor response, cancer recurrence, or survival during breast cancer treatment.
  • A few studies suggested that antioxidants might decrease the side effects associated with treatment.
    • Vitamin E for hot flashes due to hormonal therapy
    • Glutamine for inflamed mucous membranes
  • Weak studies suggested that melatonin might enhance tumor response during treatment.

The bottom line?
The authors concluded, “The evidence is currently insufficient [to guide] the use of antioxidant supplements during breast cancer treatment.”

OK, but a recent study under laboratory conditions (not in patients) found that pretreatment with vitamin C caused a dose-dependent reduction in the anti-cancer effects of doxorubicin (Adriamycin), cisplatinum (Cisplatin), vincristine (Oncovin), methotrexate, and imatinib (Gleevec) in leukemia and lymphoma cells.

10/22/08 20:47 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.