Do antioxidants lower the side effects of chemotherapy?

Some studies suggest that cancer patients who take antioxidants are more likely to tolerate more full doses of chemotherapy.

First, the details.

  • 33 articles of 2,446 subjects were worth evaluating.
  • Antioxidants evaluated were glutathione (11), melatonin (7), vitamin A (1), an antioxidant mixture (2), N-acetylcysteine (2), vitamin E (5), selenium (2), L-carnitine (1), Co-Q10 (1) and ellagic acid (1).

And, the results.

  • 24 studies reported evidence of decreased toxicities from concurrent use of antioxidants with chemotherapy.
  • 9 studies reported no difference in toxicities.
  • Only 1 study (vitamin A) reported a significant increase in toxicity.
  • 5 studies reported the antioxidant group completed more full doses of chemotherapy or had less-dose reduction than control groups.

The, bottom line?
The authors viewed the results are encouraging. Although, statistical power and poor study quality were concerns with some studies.

As you might expect, they recommended that more “well-designed studies evaluating larger populations of patients given specific antioxidants defined by dose and schedule relative to chemotherapy are warranted.”

7/21/08 16:22 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.