Selenium Interactions

Certain metals such as lead, cadmium, arsenic, mercury and silver block the action of selenium. . . . Recent laboratory experiments have shown that high doses of zinc block the action of selenium. Therefore, one has to be careful about taking excessive amounts of zinc (over 20 milligrams per day from diet and supplements) while taking selenium [emphasis added].
Choices In Healing by Michael Lerner, page 619


I think the selenium and saffron complement one another. Selensaff, a product made by Scientific Botanicals (see Resources), is used in cancer therapy to create a redox effect—a process of improving cell function by enhancing both oxygen uptake and the excretion of oxygen waste.
Herbal Medicine Healing Cancer by Donald R Yance Jr, page 148 Zinc is important because it is an antagonist to selenium and may in itself enhance or inhibit different tumors. Selenium in minute quantities is essential to human health. According to Prasad, among the minerals, "only selenium has been shown to have a role in cancer prevention":
Choices In Healing by Michael Lerner, page 619


Vitamin E and selenium protected animals against the potent carcinogenic effects of DMBA from tobacco.
Beating Cancer With Nutrition by Patrick Quillin, page 164


Selenium acts as an antioxidant and strengthens the body's immune defense system. Thus, many of the effects which are produced by vitamin E deficiency can be reversed or prevented by selenium. Some laboratory experiments have suggested that the combination of vitamin E and selenium is more effective in preventing cancer than either of them alone.
Choices In Healing by Michael Lerner, page 619


However, one experiment has demonstrated increased susceptibility to DMBA-induced tumors when selenium deficiency was aggravated by high dietary levels of polyunsatu-rated fatty acids, and protection by a physiological supplement of selenium (0.1 pg/g) to the diet (Ip and Sinha, 1981). The interpretation of these results is further complicated because of the varied protocols used in these experiments and the knowledge that selenium interacts with many other nutrients, such as heavy metals in the diet.
Diet Nutrition Cancer by National Research Council, page 169


In some experiments, dietary zinc exceeding nutritional requirements has been shown to suppress chemically induced tumors in rats and hamsters, but when given in drinking water it counteracts the protective effect of selenium in mice...While the evidence on the effect of zinc on tumor development is complex, it strongly suggests that, in general, one should be cautious about taking zinc supplements if one has cancer. And since selenium has a wide spectrum of demonstrable anticancer effects, cancer patients should be particularly cautious with zinc, since it is a selenium antagonist. I have seen many cancer patients taking moderately large amounts of zinc as part of a comprehensive megavitamin nutritional supplement program. In view of the available scientific evidence, this is another critical example of an area where uninformed nutritional supplementation may do harm.
Choices In Healing by Michael Lerner, page 612


In addition, statistically significant protection from high levels of selenium and alpha-tocopherol occurred only when gamma- tocopherol concentrations were also high (Helzl-sourer et al. 2000).
Disease Prevention And Treatment by Life Extension Foundation, page 258


Selenium and co-enzyme Q-10. Exhibits anticancer activity especially in blocking development of colon cancer and spread of breast cancer.
Food Your Miracle Medicine by Jean Carper, page 481