When an international team of researchers led by scientists from England analyzed death rates from COVID-19 as reported from different geographical areas in China, they found statistical links between recoveries from COVID-19 and the amount of selenium in their food.1
What is Selenium?
Selenium is an essential micronutrient that’s critical to a well-functioning cardiovascular system and a healthy thyroid gland. In fact, as part of the endocrine system, your thyroid is the organ with the highest concentration of selenium and is essential for making hormones.
But perhaps selenium’s most important function is to protect you against infection.
Selenium’s Impact on Viral Infections
In reporting their findings, the English researchers pointed out that selenium – which is often found in fish, meat and cereals – has already been proven to influence the severity of a number of different viral infections in both people and animals. As an example, they explain that overall intake of selenium affects folks who have HIV and develop AIDs. Patients who consume an adequate amount of selenium enjoy a reduced risk of dying from AIDS. According to researcher Margaret Rayman, who is a professor of nutritional medicine at the University of Surrey in England, "Given the history of viral infections associated with selenium deficiency, we wondered whether the appearance of COVID-19 in China could possibly be linked to the belt of selenium deficiency that runs from the north-east to the south-west of the country."
Five Times as Many Deaths From COVID-19
The study shows that in the city of Enshi in Hubei Province, which has the highest selenium intake in China, the recovery rate from COVID-19 was about triple the average found in all the other cities in that province. But in another area, where selenium intake is just about the lowest in the world, the death rate from COVID-19 was about five times higher than in other provinces.
In addition, the scientists found that the recovery rate from COVID-19 was “associated” with people’s selenium status – which they analyzed by measuring selenium in hair samples.
Of course, the researchers, so far, are cautious in claiming that selenium is a reliable help in defeating COVID-19, writing, "There is a significant link between selenium status and COVID-19 cure rate, however it is important not to overstate this finding; we have not been able to work with individual level data and have not been able to take account of other possible factors such as age and underlying disease,” says researcher Kate Bennett, a medical statistician at the University of Surrey.
Selenium and Your Overall Health
Along with helping the immune system fight off viruses, research also shows that selenium may: Defend against the growth and spread of cancer: A number of studies examined in a review published in the journal Nutrients confirm selenium’s ability as a “promising chemopreventive and anti-cancer agent” against tumors in the breast, colon, lung, prostate, liver and skin.2 In fact, another review of research suggests there may even be a link between selenium deficiency and certain types of cancer.3
Protect against cognitive and motor decline: A study by researchers at Johns Hopkins University School of Medicine, among others, found that lower levels of selenium are linked to “significantly decreased performance in neurological tests of coordination among older adults.”4 Meanwhile other studies have suggested that selenium’s ability to protect brain and nerve cells against oxidative stress might make it a great preventive against Alzheimer’s Disease.5
Reduce damage to the body from DDT and other pesticides: A study at the University of Cordoba in Spain shows that selenium may stimulate cellular antioxidant defenses and reduce damage caused by oxidative stress caused by pesticides.6
Improve men’s sperm quality: A review study in Spain demonstrates that supplementary selenium, taken along with other nutrients like zinc, omega-3 fatty acids, coenzyme-Q10 and carnitines, may improve male fertility.7
How To Get Enough Selenium
The amount of selenium in plant food sources is determined by the quality of the soil used to grow them. This makes selenium deficiency more common in certain areas of the world. In fact, an estimated one billion people around the world are selenium deficient.
While full-blown selenium deficiency is less common in the United States, many natural doctors theorize that people with certain health conditions (like those listed above) may not have enough selenium or could benefit from higher doses.
If you choose to take a selenium supplement, be careful. Researchers caution that getting too much can be as bad as getting too little.8 The daily recommended amount for adults is 55 micrograms daily, and I suggest sticking close to that.
Brazil nuts are a rich source of selenium and probably a more pleasant – and safer -- way of getting your dose than a pill. Symptoms of getting too much selenium include hair loss, fatigue, spots on your nails and stomachache.
- Zhang J, Taylor EW, Bennett K, Saad R, Rayman MP. Association between regional selenium status and reported outcome of COVID-19 cases in China. Am J Clin Nutr. 2020 Jun 1;111(6):1297-1299. doi: 10.1093/ajcn/nqaa095. PMID: 32342979; PMCID: PMC7197590. https://pubmed.ncbi.nlm.nih.gov/32342979/?from_term=Rayman+MP&from_sort=date&from_pos=1
- Chen YC, Prabhu KS, Mastro AM. Is selenium a potential treatment for cancer metastasis? Nutrients. 2013 Apr 8;5(4):1149-68. doi: 10.3390/nu5041149. PMID: 23567478; PMCID: PMC3705340. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3705340/
- Dennert G, Zwahlen M, Brinkman M, Vinceti M, Zeegers MP, Horneber M. Selenium for preventing cancer. Cochrane Database Syst Rev. 2011 May 11;(5):CD005195. doi: 10.1002/14651858.CD005195.pub2. Update in: Cochrane Database Syst Rev. 2014;3:CD005195. PMID: 21563143; PMCID: PMC3692366. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3692366/
- Shahar A, Patel KV, Semba RD, Bandinelli S, Shahar DR, Ferrucci L, Guralnik JM. Plasma selenium is positively related to performance in neurological tasks assessing coordination and motor speed. Mov Disord. 2010 Sep 15;25(12):1909-15. doi: 10.1002/mds.23218. PMID: 20687175; PMCID: PMC3270688. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3270688/
- Loef M, Schrauzer GN, Walach H. Selenium and Alzheimer's disease: a systematic review. J Alzheimers Dis. 2011;26(1):81-104. doi: 10.3233/JAD-2011-110414. PMID: 21593562. https://www.ncbi.nlm.nih.gov/pubmed/21593562
- Morales-Prieto N, Ruiz-Laguna J, Abril N. Dietary Se supplementation partially restores the REDOX proteomic map of M. spretus liver exposed to p,p'-DDE. Food Chem Toxicol. 2018 Apr;114:292-301. doi: 10.1016/j.fct.2018.02.047. Epub 2018 Feb 23. PMID: 29481894. https://pubmed.ncbi.nlm.nih.gov/29481894/
- Salas-Huetos A, Rosique-Esteban N, Becerra-Tomás N, Vizmanos B, Bulló M, Salas-Salvadó J. The Effect of Nutrients and Dietary Supplements on Sperm Quality Parameters: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Adv Nutr. 2018 Nov 1;9(6):833-848. doi: 10.1093/advances/nmy057. PMID: 30462179; PMCID: PMC6247182. https://pubmed.ncbi.nlm.nih.gov/30462179/
- Rayman MP. Selenium intake, status, and health: a complex relationship. Hormones (Athens). 2020 Mar;19(1):9-14. doi: 10.1007/s42000-019-00125-5. Epub 2019 Aug 6. PMID: 31388899; PMCID: PMC7033057. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7033057/
