A study found that many women being treated for breast cancer are taking at least one antioxidant supplement, often at levels much higher than recommended in a healthy diet. The researchers looked at four antioxidant supplements:
- vitamin C
- vitamin E
- beta carotene
Because the effects of antioxidant supplements on specific breast cancer treatments hasn't been thoroughly studied, this suggests that more research is needed.
Antioxidants are compounds found in fruits, vegetables, nuts, grains, and some meats, poultry, and fish. Antioxidants may help protect cells from substances called free radicals. Free radicals are produced when you're exposed to some pollution such as tobacco smoke. Your body also produces free radicals when it breaks down food. Free radicals can damage cells and may contribute to certain diseases, including cancer. Some research has suggested that antioxidants may help reduce the risk of cancer, heart disease, and age-related changes in the body. Still, it's not clear if taking antioxidant supplements at higher-than-recommended levels offers more benefits than getting the recommended amount of antioxidants from the foods you eat. Taking certain supplements at higher-than-recommended levels can cause health problems.
There are some concerns that taking antioxidant supplements during cancer treatment can interfere with certain treatments. For example, radiation therapy and certain chemotherapy medicines work by producing free radicals that attack cancer cells. Since antioxidants destroy free radicals, some doctors think taking antioxidant supplements might reduce the effectiveness of the treatment. Many oncologists tell patients not to take antioxidant supplements during treatment.
More than 760 women diagnosed with non-invasive and invasive breast cancer in 1996 and 1997 were asked about their use of four antioxidant supplements during adjuvant treatment. Adjuvant treatments are given after surgery to reduce the risk of the cancer coming back. Almost 87% (663 women) received one or more of the following adjuvant treatments:
- radiation therapy
More than 60% of the women took at least one antioxidant supplement while on adjuvant treatment.
- 39% of women getting chemotherapy took one or more antioxidant supplement during treatment
- 42% of women getting radiation therapy took one or more antioxidant supplement during treatment
- 62% of women taking tamoxifen took one or more antioxidant supplement during treatment
Most of the women (69%) who took antioxidant supplements during treatment took higher-than-recommended doses. The researchers considered a higher-than-recommended dose to be more of the antioxidant than in a Centrum multivitamin.
If you're being treated for breast cancer, you may be thinking about taking or are already taking supplements such as antioxidants to do all that you can to fight the cancer and keep it from coming back. It might be fine to do this, but it's very important to tell your doctor about ALL the supplements and medicines you take, including over-the-counter medicines and vitamins. Make sure you tell your doctor the exact dose of each supplement, vitamin, or medicine you take or are thinking about taking. Your doctor may have concerns about how these medicines and supplements may interact with your treatments or how they may affect your health. Just because you can buy a medicine, vitamin, or supplement without a prescription doesn't mean it's safe for you to take. Together, you and your doctor can decide what's best for you and your unique situation.