Antioxidants: concern about carotenoids in breast cancer
10 October 2011
Antioxidant supplements containing carotenoids have been linked to an increased risk of dying from breast cancer in women being treated for this cancer.
In the first study suggesting possible harm from a specific antioxidant used by women with breast cancer, US researchers found a twofold increased risk of breast cancer mortality with frequent use of carotenoid mixes compared with no use. Carotenoids include substances such as vitamin A, alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, lycopene and zeaxanthin.
Researchers followed up 2200 women, of whom 81 per cent were taking at least one type of antioxidant supplement, for 2 years after their cancer diagnosis (Cancer 2011; online 27 Sep).
The study was undertaken because of concern that certain antioxidants might protect cancer cells against damage by chemotherapy and radiation treatments, decreasing the effectiveness of these treatments.
The researchers also found a protective effect of vitamin C and vitamin E against breast cancer recurrence, and noted a trend towards reduced risk of death from any cause with vitamin E supplements alone. No effect was seen with multivitamin use.
Last Reviewed: 14 October 2011
- 1. Greenlee H, Kwan ML, Kushi LH, et al. Antioxidant supplement use after breast cancer diagnosis and mortality in the Life After Cancer Epidemiology (LACE) cohort. Cancer 2011 Sep 27. [Epub ahead of print]. doi: 10.1002/cncr.26526. http://onlinelibrary.wiley.com/doi/10.1002/cncr.26526/abstract (accessed Oct 2011).
