NMU – 182 Selenium, Immunity, and Cancer
Nutrition/Natural Medicine Update No 182 (November 19, 2020)
with Dr. James Meschino
Topic: Selenium, Immunity, and Cancer
Source: J Frontiers in Nutrition 2020 and Others (See Below)
In the September 2020 issue of the journal Frontiers in Nutrition, the researchers review the studies looking at the role of the mineral selenium on immune function. They cite the evidence showing that selenium deficiency in animals and low selenium status in humans increases susceptibility to viruses, other pathogens, and possibly cancer. They also show that providing selenium supplements to patients with the HIV-virus, slows the progression of the disease and helps to bolster T-Helper Cell numbers, which is a critical part of keeping these patients healthy and functional. They also cite other studies where selenium supplementation has also been used successfully to mitigate the impact of other serious viral and other infections. To this end, it has long been recognized that selenium is a nutrient that helps support immune function. Selenium is required to optimize antioxidant protection within cells, including immune cells, but it also exerts other multi-faceted effects that help optimize immune function and prevent certain viruses from mutating within the body and becoming more virulent, and life-threatening.
Moreover, they cite the study by Zhang and fellow researchers, which shows that patients in China who had superior selenium status had much better recovery rates from COVID-19 than patients with sub-optimal selenium status. The researchers state that “having a higher-than-normal selenium status may offer protective benefit against detrimental effects of the viral infection.” The same findings have also been shown in Germany, whereby serum selenium levels were highly correlated with COVID-19 outcome in hospitalized patients. Very low serum selenium status was present in 44.4% of their patients. Sixty-five percent of those who died had low serum selenium vs. 39% in those who survived. And overall, those with the lowest serum selenium had a much higher risk of death. The authors of this review paper suggest that until a vaccine is available that the healthcare system should encourage adults to take additional selenium in supplement form to help bolster immunity and reduce the virulence of the virus should one encounter or contract the COVID-19- related virus. They cite long-term studies showing the safety of ingesting 200 mcg per day of selenium, which has been shown to lower viral infection rates and cardiovascular disease in older individuals. (1)
As for cancer, in a 2020 review of the literature on this subject the researchers state, “ although several clinical trials indicated no significant benefit for selenium in preventing cancer, overwhelming evidence has demonstrated that selenium and many selenium compounds, under certain circumstances, are potent anti-cancer agents”. In fact, selenium supplementation shows promise in enhancing the anti-cancer effects of several common chemotherapy drugs used presently in cancer treatment. (2) Many observational studies (epidemiological studies) have shown that individuals with higher serum selenium levels and/or toenail selenium concentrations (a better long-term indicator of selenium status) have a lower risk of developing many different types of cancer. (2)
By and large, most North Americans are thought to ingest the basic recommended amount of selenium each day from food, which is set at 55 mcg per day. (3) However, in the Frontiers in Nutrition journal article the researchers suggest that higher amounts of selenium intake day are likely needed to help optimize immune function and reduce viral infections, especially as people become older. (1) Many people in our society acquire extra selenium from a high potency multiple vitamin and mineral supplement, which typically provides 50-200 mcg per day of additional selenium. (3)
I have included the references for this information in the text below
References:
1 Hiffler L et al. Selenium and RNA virus interactions: Potential implications for SARS-CoV-2 infection (COVID-19): Frontiers of Nutrition, September 2020: https://www.frontiersin.org/articles/10.3389/fnut.2020.00164/full
2. Int J Mol Sci. Tan HW et al. Selenium species: Current status and potentials in cancer prevention and therapy. 2019; 20(1):75 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6337524/
3. National Institutes of Health: Office of Dietary Supplements: Selenium https://ods.od.nih.gov/factsheets/Selenium-HealthProfes%20sional/
Eat Smart, Live Well, Look Great,
Dr. Meschino