New Study Warns Against Supplement Use During Breast Cancer Treatment

By Cancer Foundation on February 4 / 2020


Antioxidants – vitamins, minerals, or phytochemicals known for their ability to protect cells from damage – have long been studied and used for their many health benefits. However, a recent study has shown that taking antioxidants during chemotherapy treatment for breast cancer may actually be detrimental to a patient’s treatment outcomes.

“Patients using any antioxidant before and during chemotherapy had an increased risk of their breast cancer returning and, to a lesser degree, had an increased risk of death. Vitamin B12, iron, and omega-3 fatty acid use was also associated with poorer outcomes,” said Christine B. Ambrosone, PhD, of Roswell Park Comprehensive Cancer Center and leader of the study.

While the study group was relatively small, the results showed a significant link between the use of antioxidants and cancer relapse or death. Patients taking antioxidants like Vitamins A, C, E, or carotenoids, or Coenzyme Q10 before and during chemotherapy were up to 41% more likely to experience cancer recurrence.

“One way chemotherapy works is by generating lots of oxidative stress,” Ambrosone summarized. “The thinking is that antioxidants may block oxidative stress and make chemotherapy less effective.”

Prior to the study, many doctors were already encouraging their patients to avoid using antioxidants while undergoing chemotherapy, knowing that the protection these supplements offer to healthy cells may actually protect cancerous cells as well. But until recently, there was a lack of strong data to support the recommendation.

Now, healthcare professionals have a little bit more information they can share with patients with questions about using supplements during cancer treatment.

But a number of questions remain, particularly in regards to which supplements may be safe, helpful, or at least not harmful to those undergoing cancer treatment.

Click here to read more about the study, and speak to your oncologist directly if you have questions regarding your own treatment plan.

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