The concurrent use of antioxidants in the form of food supplements and cancer whilst undergoing chemotherapy and radiotherapy has been subject to a variety of conflicting opinions. At present it would be fair to say that most oncologists take the conservative line that antioxidants reduce the effectiveness of chemotherapy and should therefore be avoided.
This inevitably causes confusion and contradictions when the literature is less equivocal and suggest quite the opposite at times.
A paper out in Dec 2010 raises a further interesting development where in a prospective trial looking at almost 5,000 women with breast cancer in the 6 months after diagnosis and following them for just over 4 years there was a statistical benefit to those who took antioxidants’.
The researchers state:
CONCLUSIONS: Vitamin supplement use in the first six months after breast cancer diagnosis may be associated with reduced risk of mortality and recurrence.
Impact: Our results do not support the current recommendation that breast cancer patients should avoid use of vitamin supplements.
What was the benefit
The study found that women who consumed vitamin E vitamin C and multivitamins had an 18% reduced mortality risk and a 22% reduced risk of re-occurrence just for the use of a simple nutrient complex.
There are many cancers and to extrapolate this out to other cancers is just conjecture, but the blanket opposition to antioxidants needs careful review as some cancers may do better with and others without. From a clinical perspective one of the overriding complications of chemotherapy is immune suppression and secondary illnesses. The use of concentrated nutrients are known to aid immune health and should be considered a sensible addition to a patients protocol, with avoidance on the day of chemo to appease oncology opinion and play the conservative game.
 Nechuta S, Lu W, Chen Z, Zheng Y, Gu K, Cai H, Zheng W, Shu XO. Vitamin supplement use during breast cancer treatment and survival: a prospective cohort study. Cancer Epidemiol Biomarkers Prev. 2010 Dec 21. View Abstract