Zinc and selenium improve health of cancer patients – Literature Review & Commentary – Brief Article
Alan R. Gaby
Sixty patients (median age 55 years) with cancer of the digestive tract (colon, stomach, or esophagus) who were undergoing chemotherapy were randomly assigned to receive supplemental zinc (21 mg/day) and selenium (200 mg/day) for 50 days or no supplemental zinc and selenium (controls). At baseline and after 60 days, all patients were malnourished, as determined by various anthropometric and biochemical parameters. However, 70% of patients treated with zinc and selenium showed no further worsening of nutritional status and experienced a significant decrease of asthenia and an increase of appetite. In contrast, only 20% of control patients showed no further worsening of nutritional status.
Comment: These results suggest that supplementation with selenium and zinc may improve the general condition of patients with cancer of the digestive tract who are undergoing chemotherapy. Some oncologists have expressed concern that concomitant use of antioxidants such as zinc and selenium might interfere with the anticancer effect of chemotherapy. The basis of their concern is that many chemotherapy drugs promote the formation of oxygen-derived free radicals, and that these free radicals might be scavenged or quenched by antioxidants. It is true that many chemotherapeutic agents cause free radicals to form; however, the anticancer effects of these drugs do not, in general, seem to depend on the formation of free radicals. Consequently, antioxidants might reduce the adverse effects of the drugs, without inhibiting their beneficial effects. While the bulk of the evidence available to date supports that possibility, more research is needed to determine which antioxidants can be used safely and effectively with which chemotherapeutic agents.
Federico A, et al. Effects of selenium and zinc supplementation on nutritional status in patients with cancer of digestive tract. Eur J Clin Nutr 2001;55:293-297.
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