Vitamin Use After Breast Cancer Diagnosis: Antioxidant Safety

Is it safe to take antioxidants during breast cancer treatment? According to a recent study in the journal Cancer, the answer may depend on the type of supplement and the dose.

The study

The study examined the association between antioxidant use and breast cancer recurrence and survival in 2,264 women with early-stage breast cancer. 81% took antioxidants after diagnosis, either individually or in multivitamin form. (Links to the study and Reuters and Indianapolis Star articles may be found on the multivitamin page of our website.)

Vitamin C and vitamin E

Taking single supplements of vitamin C or vitamin E six or seven times a week was associated with a lower risk of breast cancer recurrence. Vitamin E was also associated with a decreased risk of death from any cause.

However, the lead researcher noted that much of this benefit may be due to a "healthy user bias," meaning women who take supplements "tend to have healthier habits in general."

Carotenoids: Vitamin A, beta-carotene and lutein

On the other hand, "frequent use" of any combination of carotenoids, such as vitamin A, beta-carotene and lutein, was associated with an increased risk of death from breast cancer or any other cause. Of 89 women who took carotenoids six to seven days a week, 18 percent died of breast cancer, compared to less than 7% of women who did not.

Because these patients would also have a "healthy user bias," the lead researcher noted the findings on the increased risk of death "are even more striking."

Multivitamins

The study findings did not pertain to multivitamin use, which "generally have more moderate doses of individual nutrients."

Notes of caution from the researchers

Heather Greenlee, lead researcher, told Reuters that the study "adds to the growing body of literature suggesting that dietary supplements containing high doses carotenoids may be harmful, and people should think twice before taking them."

At LATESTBreastCancer.com, we follow breast cancer news and research daily. We highlight interesting developments in this blog and add links to medical journal abstracts and news articles to the treatment pages of our website. We sort news and research by test, treatment option and complementary therapy. Our goal is to make internet research easy. We look forward to keeping you posted.