(HealthDay News) – The use of the antioxidant beta-carotene during radiation therapy treatment for prostate cancer is not associated with an increase in prostate cancer deaths or metastases, according to research published in the May issue of the International Journal of Radiation Oncology*Biology*Physics.

To investigate whether supplemental beta-carotene use during radiation therapy is associated with an increased risk of cancer death or metastases, Danielle N Margalit, MD, MPH, of the Harvard Radiation Oncology Program in Boston, and colleagues conducted a prospective, randomized study (as part of the larger Physicians’ Health Study) involving 383 men receiving radiation therapy for prostate cancer. Participants were randomly allocated to receive beta-carotene (50mg on alternate days) or placebo and were followed for a median of 10.5 years.

The researchers found that there was no significant difference in the risk of lethal cancer in the beta-carotene group compared with the placebo group (hazard ratio, 0.72; P=0.24). The difference remained nonsignificant after adjustment for confounding variables. In the beta-carotene and placebo groups, the 10-year freedom from lethal prostate cancer was 92% and 89%, respectively.

“In summary, our data show that the use of supplemental beta-carotene during radiation therapy at doses commonly found in nutritional supplements is not associated with the risk of prostate cancer death or metastases,” the authors write.

One of the authors disclosed financial ties to companies which manufacture nutritional supplements and to the California Strawberry Commission and Tomato Products Wellness Council.

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