ABSTRACT
Epidemiological studies show that higher selenium intake is associated with a reduction in tumors at various sites, including mammary tissue. The efficacy by which selenium inhibits chemically-induced, virally-induced and transplantable tumors makes it a unique dietary nutrient. Overall, considerable epidemiological and laboratory investigations support selenium as an effective anticarcinogenic agent. The geochemical environment in which food is produced can markedly influence the dietary selenium intake. Various indices of selenium status are known to correlate with the selenium content of locally grown plant crops. The selenium status of an individual may also influence the biological behavior of some neoplastic cells. A variety of studies have established that dietary selenium supplementation can significantly inhibit the incidence of chemically induced tumors in animals. The majority of studies examining selenium as an anticarcinogenic agent has used supplements throughout the experimental feeding period. Epidemiological and laboratory investigations reveal an inverse relationship between selenium intake and cancer risk.
