Experts conducted a research to assess if selenium is effective in the prevention of cancer by inhibiting cancer-associated angiogenesis. The process of angiogenesis (development of new blood vessels) is essential for the genesis and growth of solid cancers.

It was discovered that increased selenium intake as selenium-enriched garlic, sodium selenite or Se-methylselenocysteine led to a significant reduction of tumor density in breast cancers during continuous exposure for seven weeks. The results indicated that selenium metabolites could possess key attributes (such as proliferation, survival and cell matrix degradation) of endothelial cells, which are essential for angiogenesis to begin. Hence the inhibition of angiogenesis associated with cancer may be a mechanism for the anticancer activity of selenium in vivo.

Test findings indicated that there were significantly lower levels of vascular endothelial cell growth factor activity in a sizeable proportion of the selenium-treated cancers as compared to the control group. In contrast to the breast cancers, the selenium treatment did not alter affect the microvessel density of the mammary glands that were not affected by cancer.

The Mol Carcinogen (99, Vol 26, Iss 4, pp 213-225) further observed that in cell culture, direct exposure of the human umbilical vein endothelial cells to selenium induced cell death predominantly through apoptosis.

Selinium is an important anti-aging mineral with potent antioxidant properties. As you age, your levels of selenium fall. Selenium blood levels dropped 7% after 60 years of age and 24% after 75 years of age. Declining levels of selenium signifies less antioxidant activity in our body. People with decreased levels of selenium are associated with higher incidences of heart disease, cancer, and arthritis.

A study conducted at the University of Arizona of 1,700 elderly Americans showed that those with low levels of selenium are more apt to have polyps in the gastrointestinal tract (33% compared to 9% in those with a high level of selenium). The same study showed those taking 200 mcg of selenium over 4.5 years have 63% less prostate cancer, 58% fewer colorectal cancers, and 46% fewer lung cancers. Overall, there were 30% fewer new cancers, and 50% less overall death from cancer. Another study of 3,000 older Dutch people showed a reduction of lung cancer risk by 50% for those on selenium. The good news is that selenium is readily available in the Brazil nut. The average Brazil nut comes in a shell that contains 100 mcg of selenium (due to the soil). The average Brazil nut that comes already shelled contains 12-25 mcg of selenium (grown in another part of Brazil). Selenium is also found in grains, sunflower seeds, meat, seafood especially tuna, swordfish, and garlic. The optimum intake for anti-aging purposes is 75-200 mcg a day.

Most common multi-vitamins do not contain that much selenium and therefore most likely you will need a separate selenium capsule as supplement. Toxicity dose is around 2500 mcg a day. Toxicity symptoms include: hair loss, liver damage, joint inflammation which can be seen after 5000 mcg selenium a day