With the advent of genetic testing, scientists are able to assess breast cancer risk with greater accuracy using new and insightful information. But with that advance comes the risk of over-treatment with unnecessary surgeries and harmful substances. As most women know, the genes associated with breast cancer are known as the BRCA genes. When functioning properly, the BRCA (short for breast cancer) genes are responsible for repairing damaged DNA. When mutated, they malfunction, leaving damaged DNA in place and thereby promoting the growth and spread of cancer. When you inherit a mutated copy of a BRCA gene, your risk of developing breast cancer can escalate to as high as 80 percent. Fortunately, inheriting an aberrant gene is not sure to lead to a diagnosis of breast cancer; in fact, the mineral selenium has been shown to level the playing field.

Selenium has long been recognized as one of the most effective nutrients for natural protection from breast cancer, and other cancers as well. It has anti-oxidative properties, boosts the immune system, and is necessary for manufacturing glutathione. Glutathione, the body’s own natural antioxidant, helps you remain healthy by keeping free radicals in check, detoxifying metals and cancer-causing compounds, helping to transport amino acids into cells, and much more. Malnutrition, stress, and toxicity can all deplete our glutathione levels, putting our immune systems at risk. Most importantly for women who have an increased risk of breast cancer, selenium seems to prevent damaged DNA from replicating, thus helping to stop cancer before it starts.

Hundreds of studies confirm this, beginning in the late 1950s and ongoing today. In 2006 an entire issue of Biomedical and Life Sciences was devoted to examining selenium as an anti-cancer agent, its authors (Combs and Lü) concluding:

Most epidemiological studies have shown inverse associations of selenium (Se) status and cancer risk; almost all experimental animal studies have shown that supranutritional exposures of Se can reduce tumor yield; and each of the limited number of clinical intervention trials conducted to date has found Se treatment to be associated with reductions in cancer risks.1

When looking at women who are genetically predisposed to breast cancer, results seem to be even more profound. In a small but potentially groundbreaking study published in the medical journal Cancer Epidemiology, Biomarkers & Prevention, researchers found that selenium supplementation normalized DNA damage in women who had an increased risk of developing breast cancer. 2 After splitting subjects into two groups (those with a mutated BRCA1 gene, and their relatives with a healthy BRCA1 gene), they recorded the differences in the amount of DNA damage by measuring how many breaks there were per cell.

For the relatives with a normal BRCA1 gene, there were 0.39 breaks per cell, on average. For the women with an abnormal BRCA1 gene, the average was 0.58 breaks per cell. Keep in mind that more breaks means more damage and a higher risk of developing cancer. With one to three months of selenium supplementation, women with a mutated BRCA1 gene reduced the average ‘breaks per cell’ to 0.40, virtually identical to the 0.39 breaks found in the women with healthy BRCA1 genes. It’s no wonder that selenium is regarded as an anti-cancer nutrient!

Food Sources of Selenium

Unfortunately, not many of us obtain the recommended dose of 200 micrograms a day. The amount of selenium in soil has steadily declined over the years, reflected in diminishing levels of selenium in fruits and vegetables. The amount of selenium in food fluctuates depending on where it was grown and while selenium can induce toxic effects in very large doses, most of us are actually deficient in this mineral. Good sources of selenium include mushrooms, organic egg yolks, seafood, poultry, whole grains, broccoli, asparagus, and Brazil nuts. In fact, eating just a few Brazil nuts a day will meet your daily requirement!

It’s important to consult with a qualified nutritionist or integrative health practitioner about the pros and cons of supplementation. Should you chose to supplement with selenium, I usually recommend  Se-methylselenocysteine (SeMSC), a naturally occurring, organic selenium compound found in garlic and broccoli, whose effectiveness has been established both in the lab and in animals.

While anyone can enjoy the perks of a selenium-rich diet, women with the cancer-promoting mutations of the BRCA genes stand to benefit the most. That selenium can repair damaged DNA to nearly match the levels of those with healthy BRCA genes is a fact that the medical community and all women (and men!)  should not overlook. Whichever way you choose to ingest it, selenium is a mighty mineral with regards to cancer protection.