Antioxidants and the prevention of hormonally regulated cancer

Epidemiological studies provide convincing evidence that a diet rich in antioxidant-containing foods, mostly fruits and vegetables, is associated with a lower incidence of most cancers, but results on hormonally regulated cancers, such as breast and prostate cancer, are inconsistent. Although studies in animals and cell cultures affirm the cancer preventive potential of single and/or combined antioxidant supplements, most intervention trials using supplementation with single or multiple antioxidant nutrients, given at relatively high doses, have not shown a consistent effect in reducing cancer risk. Intervention with a vitamin E supplementation reduced the risk of colorectal adenomas and prostate cancer and selenium supplementation reduced the incidence of total cancer, prostate, lung and colorectal cancer. Differences between the sexes in the reduction of cancer risk following antioxidant supplementation are partly due to differences in baseline values, metabolism and hormonal regulation. Among ...