Supplements and chemotherapy side effects

Chemotherapy patients should discuss taking supplements with their doctors, because some supplements may interfere with treatment. For instance, cod liver oil might interfere with blood thinning drugs, hormone treatment or chemotherapy. Breast cancer patients who take a multivitamin experience a small decrease in blood cells, which help fight bacterial infections.Previous research has shown that a herbal dietary supplement, used by some men to treat prostate cancer, may interfere with the anti-cancer activity of the chemotherapy drug paclitaxel, thus making it less effective.Studies have also shown that vitamin E might enhance the benefits and reduce the side effects of chemotherapy, and many doctors now recommend vitamin therapy during treatment.

To investigate whether supplements help reduce side effects from chemotherapy, researchers from the University of Vermont in Burlington asked 49 women with breast cancer to complete questionnaires detailing their use of supplements during chemotherapy.The investigators found that more than 70 per cent of the women were taking at least one of 165 different types of supplements. On average, patients took three supplements. However, some women said they took up to 20 daily supplements during treatment. The most common supplements were multivitamins, vitamin E and calcium.

Women who took multivitamins or vitamin E alone experienced a smaller decrease in neutrophils during chemotherapy. However, women with relatively high levels of folate (B-vitamin) in their blood had a larger-than-average decrease in neutrophils.Many cancer patients and people without cancer take supplements because they believe they are natural, and could therefore only help them.
Supplements typically consist of complex chemicals, which can have many possible effects on the metabolism of drugs and the functioning of cells. These effects may be beneficial or detrimental and need to be studied further.

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