Highlights
Selenium, an essential mineral, obtained through our diet, is a component of the body’s antioxidant system. Use of Selenium supplement may have health benefits such as reduced incidence and mortality of multiple cancer types and also decrease the toxic side-effects of chemotherapy. However, an excess of Selenium levels may have downsides/side effects as promoting tumor growth and spread for specific cancer-types.
Selenium
Many of the minerals that we intake on a daily basis and are essential for our basic bodily functions are unheard off by the masses. One such key mineral is selenium. Selenium is an essential nutrient for human health because of the role that it plays in protecting the body against oxidative damage and infections. The amount of selenium found in a natural food is dependent on the amount of selenium present in the soil at the time of growth so it varies among different foods from different regions. However, one is usually able to fulfil their selenium requirements through eating brazil nuts, seafood, meat, and grains.

Recent scientific studies have shown that in addition to general health benefits, an element like selenium can play a positive role in cancer therapy. But like all natural products, these benefits do not apply to all members of the population. Therefore, here’s a list of pros and cons of what selenium can do for one’s body.
Health Benefits of Selenium in Cancer
Following are some of the health benefits of Selenium in Cancer.
1. Selenium is an essential component of antioxidant systems in the body which aids in protecting the body from free radicals (Zoidis E, et al, Antioxidants (Basel), 2018; Bellinger FP et al,Biochem J. 2009).
- Free radicals are byproducts of various metabolic processes in the body and are dangerous if built up in large amounts because it can cause oxidative stress and lead to DNA mutations, potentially leading to various disorders including cancer, cardiovascular diseases, immune dysfunctions and neurological disorders.
2. Selenium Supplement use has the ability to greatly reduce the incidence and mortality of multiple cancer types.
- Supplement of 200mcg/day reduced prostate cancer incidence by 50%, lung cancer incidence by 30%, and colorectal cancer incidence by 54% (Reid ME et al, Nutr & Cancer, 2008).
3. Selenium supplements can lead to significantly lower infection rates for Non-Hodgkin’s Lymphoma Patients
- One study showed that 67% of patients with chemo alone got an infection but only 20 % of patients with chemo and selenium got infected (Asfour IA et al, Biol Trace Elem Res., 2006).
4. Selenium has shown the ability to decrease and counteract the toxic side-effects that chemotherapy can have on cancer patients
- Able to reduce a specific chemo drug induced nephrotoxicity and bone marrow suppression (Hu YJ et al, BiolTrace Elem Res.,1997) and reduce radiation induced toxicity of a difficulty in swallowing (dysphagia) (Büntzel J et al, Anticancer Res., 2010)
5. For people not diagnosed with cancer, selenium can strengthen their immunity against developing cancer by increasing the activity of natural killer cells (Büntzel J et al, Anticancer Res., 2010)
Potential Downsides/Side-effects of Selenium Supplement Use in Cancer
Following are some of the side-effects/downsides of using Selenium supplements in Cancer.
1. Based on a patient’s individual genetics and cancer sub-type, Selenium can potentially counteract chemo medication and actually aid the tumor in its growth
- Selenium supplementation has been shown to progress certain mesothelioma tumors (Rose AH et al, Am J Pathol., 2014)
2. Mice fed Sodium Selenite resulted in extreme metastasis (spreading) of cancer cells (Chen YC et al, Int J Cancer., 2013)
3. All the anti-cancer benefits of selenium may only apply if selenium levels in the patient are already low. Selenium supplementation of patients who already have enough selenium in their body can lead to an increased risk of type 2 Diabetes (Rayman MP et al, Lancet. 2012)
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer. Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.