New research suggests that although antioxidants have been billed as a wonder supplement, they may be detrimental to patients undergoing chemotherapy or radiation therapy for cancer.
Patients are advised that multivitamins may still be acceptable, even simple supplements such as green tea, vitamin A, and vitamin E can cause serious problems for patients undergoing chemotherapy or radiation therapy.
The supplements “may decrease the effectiveness of radiation or chemotherapy or even make the toxicities of these treatments worse,” Lawenda said. “I would recommend that you do not take these agents during chemo or radiation.”
Dr. Lawenda says that cancer patients take antioxidant supplements because they are considered part of a “healthy lifestyle” in today’s world, mainly because of their role in protecting cells from threats throughout the body.
“Everybody wants to take them,” said Dr. Alfred Neugut, the head of cancer prevention and control for the Herbert Irving Comprehensive Cancer Center at Columbia University in New York City. “It comes up almost every day in almost anyone’s practice.”
Dr. Lawenda and others have challenged conventional wisdom, and now believe that antioxidants may be harmful to patients being treated for cancer. They found that out of all the studies performed on the interaction between radiation and antioxidants, only three relied on randomized controlled trials.
One of the randomized controlled trials showed that the use of antioxidants during cancer treatment raised the likelihood of the patient’s death.
“The quality of these studies, in terms of many of the details, is not sufficient enough for us to make strong recommendations to our patients on the safety of using these agents during radiation or chemotherapy,” Lawenda said.
Because of the inconclusive nature of the data, it’s unclear whether doctors should recommend the cessation of all supplements during cancer treatment, or if limited supplementation is acceptable.
Still, “we don’t know whether even a multivitamin is OK to take,” he added. “We don’t know if even the USDA levels are acceptable. We just don’t know the answers to so many questions, unfortunately.”