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Vitamins to avoid with cancer

January 2, 2020 By Jane Sadler

Like water and oil, vitamin supplements do not blend well with breast cancer and (very possibly) other cancers. Many of our patients take vitamin supplements with the notion they will achieve greater health. For our cancer patients, however, a different approach should be considered.

A recent study released by the Journal of Clinical Oncology  suggests  using antioxidant supplements during chemotherapy for breast cancer could negatively impact treatment efficacy. Many cancer therapies rely on the generation of reactive oxygen species (ROS). The use of antioxidants could therefore negate any treatment gains and potentially reduce treatment benefits thru their anti-. 

The study involved 1,134 breast cancer patients on similar chemotherapy regimens. Patient’s use of antioxidant vitamins: C, A, and E, carotenoids, and coenzyme Q10 were associated with a 41% increase risk for breast cancer recurrence when used both before and during chemotherapy. 

In addition, the use of non-antioxidant vitamins iron and vitamin B12 supplements were also shown to increase the risk of breast cancer recurrence and death. Iron allows the production of ROS which contributes to malignant transformation; in addition, tumors rich in iron content will tend to multiply. Iron may also interfere with antitumor immunity. Reasons for B12 supplement interference with cancer recovery and poorer outcomes is not certain but its negative effects were evident in the study.

Two items of interest from this study:

  1. General use of multivitamins either before or during chemotherapy had no effect on cancer recurrence or recovery
  2. omega-3 polyunsaturated fatty acid (an anti-oxidant) was associated with a decreased risk of cancer recurrence when levels were “derived from fish-intake” (i.e. eating fish) and not from supplements. 

Bottom line: Eat healthy, colorful, natural foods especially if you have been or are currently being treated for cancer. Unless prescribed by your doctor, the use of supplements should be avoided. IF you have no history of cancer, eat a balanced diet and consider exchanging your vitamin supplements for fresh foods.

Advice From The Doctor

Jane Sadler, M.D.

Sadler is a regularly-featured expert in The Dallas Morning News as their medical blogger in addition to several well-known national magazines including Cosmopolitan, Teen Magazine, Glamour, Redbook, and Shape Magazine to name a few. She has been quoted on Yahoo! and Forbes Information sites in addition to many others. She appears regularly in the Dallas/Fort Worth television and radio markets as an expert on women's health. Sadler has a passion for healthy lifestyles and is committed to arming women with the knowledge to more positively affect their quality of life.

Read more from Jane Sadler at the Dallas Morning News
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