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Selenium counteracts cancer - and is likely to break the curve

Selenium counteracts cancer - and is likely to break the curveAlthough cancer treatments have improved drastically, science has still not managed to break the curve. On the contrary. A growing number of people contract cancer, and that is why we should focus more on the trace element, selenium, which possesses several mechanisms against cancer. However, it requires that we get enough selenium and that is in a form that the body is able to utilize optimally.

According to statistics from the Nordic database NORDCAN, the number of cancers will increase by more than 50% in the years to come. Cancer is currently the leading cause of death among people younger than 65 years of age. Many of those who follow the official healthy lifestyle recommendations by maintaining their ideal weight, limiting their alcohol intake, exercising regularly, and choosing not to smoke, are also affected by cancer. Although there are many things that cause cancer, it looks as if too little selenium is an important yet underestimated factor.

Low selenium intake in Europe

The agricultural soil in Europe generally contains very little selenium. The problem has been made even worse by intensified farming methods that deplete the soil additionally. A low intake of fish and organ meat also contributes to the low selenium status. An estimated 20% of the Scandinavian population fails to get the recommended daily allowance (RDA) for selenium, which is around 50-70 micrograms per day. In many other countries such as the United States, Canada, and Japan, the natural selenium intake from dietary sources is substantially greater and easily reaches 200 micrograms, the level that is used in many scientific studies of selenium.

Did you know that for decades, farmers have been giving selenium supplements to their animals to prevent serious deficiency diseases, simply because healthy livestock equals a healthy economy?

It is important to choose supplements with organic selenium yeast

Back in 1996, the American researcher Larry Clark documented with the so-called NPC Study (National Prevention of Cancer) that supplementing with 200 micrograms of organic selenium yeast with a variety of organic selenium compounds could reduce the risk of several common cancers by 46-63%, while reducing cancer mortality by 50%. In practice, this means that millions of people would be able to survive or avoid, altogether, the dreaded disease.

The results of the NPC study were that groundbreaking, the study was terminated ahead of schedule. It was considered unethical to continue the study with a placebo group that did not benefit from the selenium yeast.

Selenomethionine supplements do not work, and studies are misleading

Unfortunately, many people refer to the subsequent SELECT trial, in which selenium supplements were given in combination with vitamin E. However, this study failed to show a protective effect on cancer. One reason why the study did not show a similar results as those seen in the NPC study is that the scientists used a form of selenium called selenomethionine. Unlike organic selenium yeast, selenomethionine has not demonstrated good results with cancer. Moreover, a synthetic form of vitamin E was used. It is therefore misleading when people refer to the SELECT study in an attempt to discourage the use of selenium in the prevention of cancer. It would be more correct to inform that supplements of selenomethionine should not be expected to have an effect and to recommend selenium yeast instead.

Poor selenium status precedes the disease

It often takes 10-15 years from the time the first cell mutation takes place until tumors occur. At the same time a selenium deficiency leaves the cells more vulnerable, as they mutate more easily and tend to migrate to other tissues.
Several large-scale studies have shown a difference in blood selenium levels of cancer patients and healthy controls years before the disease surfaces. Because it often takes several years for cancer to develop, selenium is vital for long-term prevention.

Selenium induces programmed cell death and prevents tumors from spreading

The different selenium-containing proteins counteract two specific characteristics of cancer cells: One is to inhibit the stupendous ability of cancer cells to form new blood vessels when spreading. The other is cancer cells' lacking ability to perform programmed self-destruction (apoptosis). This is a process which normal cells carry out as a protective measure once they begin to malfunction.

Prevents breast cancer and increases the chance of surviving the disease

Scientists have also observed differences in blood selenium levels of breast cancer patients and healthy individuals long before the disease is diagnosed. As breast cancer is one of the most common cancer forms, selenium definitely deserves more attention, both in terms of using it for prevention and introducing relevant campaigns. Women with breast cancer also have an increased chance of survival if they consume more selenium before the disease compared with women who fail to get adequate selenium from their diets. This was seen in a Swedish study of 3,146 breast cancer patients.

Selenium protects against prostate cancer

According to a study from the Technical University of Denmark, consuming 200 micrograms of selenium per day lowers the risk of prostate cancer. This dosage is substantially higher than the recommended daily allowance (RDA).

Selenium controls the immune system, which is derailed in many types of cancer

Researchers from the University of Copenhagen published a study in which they demonstrated how the selenium compound methylselenol was able to prevent cancer cells from spreading as a result of cellular stress and a derailed immune. With malignant melanoma, prostate cancer, and certain types of leukemia, the cells overproduce certain compounds called NKG2D, which overstimulate, confuse, and exhaust the immune system, eventually causing it to break down. According to the Danish researchers, methylselenol inhibits the uncontrollable NKG2D production and limits the presence of these harmful compounds in the bloodstream.

How selenium protects against cancerous substances

Most carcinogens have one thing in common and that is that they either function as free radicals themselves or instigate the body to generate free radicals. Free radicals are harmful and very aggressive oxygen compounds with the potential to damage cellular DNA. Selenium-containing proteins called GPX function as powerful antioxidants that protect cells and their DNA against free radical attacks. Other selenium compounds neutralize cancerous environmental toxins like mercury. And the selenium compound, selenoproteins P, is able to repair DNA damage and prevent cells from turning into cancer cells.

Selenium's six anti-cancer mechanisms

  • powerful antioxidant that protects cells against free radicals
  • repairs DNA damage
  • Inhibits the formation of new blood vessels in tumors (anti-angiogenesis)
  • Causes diseased cells to self-destruct (apoptosis)
  • Contributes to an effective immune defense
  • Regulates the production of substances that may overstimulate the immune system


Clark LC et al: Effects of Selenium Supplementation for Cancer Prevention in Patients with Carcinoma of the Skin. Journal of the American Medical Association. 1996

Klein EA et al. Vitamin E and the risk of prostate cancer: The Selenium and Vitamin E Cancer Prevention Trial (SELECT). Jama 2011.

Harris HR, et al. Selenium intake and breast cancer mortality in a cohort of Swedish women. Breast Cancer Res Treat. 2012.

Hagemann-Jensen Michael et al. The Selenium Metabolite Methylselenol Regulates the Expression of Ligands That Trigger Immune Activation through the Lymfocyte Receptor NKG2D. The Journal of Biological Chemistry. 2014.

Heath, J.C. et al: Dietary selenium protects against selected signs of aging and methylmercury exposure. Neurotoxicology, 2010.

Hertz Niels. Selen et livsvigtigt spormineral. Ny Videnskab 2002.

Dansk jordbrugsforskning. Selenanvendelse i dansk landbrug. 2006.

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