Taking Antioxidant Supplements During Cancer Treatment

The use of antioxidant nutrients as a complement to standard cancer treatments has risen in popularity despite varying reports of their effectiveness. While a review of the clinical data suggests that antioxidant intake can have some influence on the efficacy and side effects of cancer therapy, the results are sometimes contradictory, making it difficult to give general recommendations. These discrepancies may be related to the type of cancer, the mechanism of action of the drugs used in treatment, and the type of antioxidants taken.

Two opposing views exist regarding the use of antioxidants taken during cancer treatment (chemotherapy and radiation). One view takes a complimentary approach utilizing antioxidant supplements to improve the efficacy and/or tolerability of standard therapies. The alternate view, which is held by most standard oncologists, recommends against taking nutritional supplements during cancer treatment because of the possibility that antioxidants might protect cancer cells from damage by cancer treatments.

Evidence Supporting the Use of Antioxidant Supplements During Cancer Treatment

Several nutrients have been shown to have a beneficial or synergistic effect when used in conjunction with cancer treatment. When taken together, supplementation of soy protein, vitamin E, and selenium has been demonstrated to slow the progression of prostate cancer when taken with prostate cancer treatments. Similarly, in a study of 370 patients with non-small-cell lung cancer or gastrointestinal cancer, melatonin combined with chemotherapy increased the rate of tumor regression and survival better than chemotherapy alone.

Multiple studies demonstrate that high doses of supplementary antioxidant nutrients (vitamins A, C, and E and carotenoids) improve the negative effect of radiation therapy on cancer cell growth, and in some cases also protect normal cells against collateral damage. NAC and vitamin E have also been reported to decrease the incidence of toxic hepatitis and the need for blood transfusions in patients being treated with chemotherapy and radiation therapy for acute lymphoblastic leukemia (ALL). Also, curcumin taken with radiation therapy has been shown to have a synergistic effect in reducing tumors in head and neck squamous cell cancer (HNSCC).

Overall, NAC, melatonin, and some flavonoids (found in berries, citrus, bananas, onions, parsley, black tea, green tea, red wine and dark chocolate) appear to be the most promising antioxidants for cancer therapies.

Variable Interactions of Antioxidants in Cancer Treatment

Alternately, in other studies the use of antioxidants has been shown to have a negative effect when taken together with cancer therapy. While high doses of vitamins C and E have been shown to improve side effects when administered with radiation for HNSCC, there is also evidence that they may decrease the effectiveness of the treatment.

Similarly, vitamin C taken with certain chemotherapy agents has been shown to decrease the antitumor action of the drug in the treatment of breast cancer and even to accelerate tumor growth when given with the chemotherapy agent, doxorubicin.

Clearly, more research is needed on this subject for patients to best be able to determine the pros and cons of taking antioxidant supplements during cancer treatment. A helpful recommendation is to always let your physician know about any nutritional supplements or botanicals you are taking during treatment for any medical condition.



  • Terryl Todd
    Terryl Todd Thursday, 19 May 2016 01:46 Comment Link

    Joseph Mulholland and Jay Johnson are correct. Thanks for their comments.

  • Joseph  Mulholland
    Joseph Mulholland Tuesday, 17 May 2016 18:34 Comment Link

    The oncologist coldly said ..... We don't reccomend any vitamins and nutrients. There is absolutely nothing you can take or put in your mouth that will help you. You understand you will be dead in two months. Besides the horror of realizing this person held your partners life in her hands. I got the distinct feeling the angry response was based on dogma being an easy answer., And either the oncologist had reached the limit of her intelligence or was simply uncaring and lazy. We were only allowed to see her I believe so she could check the box that showed she had seen x number of patients to comply with the rules of her funding grants.
    She hid behind the medical wall to distance herself and not answer any questions.. Cancer is a great equalizer she too will become victim of the indifferent system she helps perpetrate She was wrong on the "less than two months to live" my partner lived 81/2 months. . I'll trust the nutrients and vitamins he took too over her advice which did not prove to be accurate.
    Billions of dollars later and 60 years after Ronald Regan declared a war on cancer. And oncologogists cannot even tell you if a vitamin is good for you or not pretty much says it all Oncology is in the dark ages. They can't even tell you if you can take turmeric but they don't hesitate to give you fearsome drugs and say you must not open your refrigerator door or the cold will shut your breathing off. wear scarves and gloves to your appointment. Nutrients ....I told you... nothing you can take that will help you. That just does not make sense ....oh we did move on to a different can't tell you if a vitamin is good oncologist. Dark ages reaping in huge rewards. I am just disgusted

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