A meta-analysis shows a significant association between low serum selenium status and rheumatoid arthritis (RA) [Yu 2016].
-The researchers examined the data from 14 case-control studies involving 716 subjects.
-The analysis of the pooled data indicated that patients with rheumatoid arthritis had lower serum levels of selenium than the healthy controls.
-The rheumatoid arthritis patients had significantly lower serum selenium levels than healthy controls did in studies in Europe and in Asia but not in studies in the USA.
Selenium and Rheumatoid Arthritis Studies
Sahebari et al [2019] reported on 13 studies that assessed selenium status in rheumatoid arthritis patients.
- All studies comparing selenium status in rheumatoid arthritis patients and controls showed lower selenium status in the rheumatoid arthritis patients. It is not uncommon that researchers find an association between low selenium intakes/status and increased incidence of autoimmune diseases like rheumatoid arthritis.
- Four of the studies analyzed by Sahebari et al showed an improvement in the clinical symptoms of rheumatoid arthritis patients compared to controls when the patients had been treated with 200-600 micrograms of selenium daily.
Adequate Selenium for Rheumatoid Arthritis Patients
Rheumatoid arthritis is a chronic inflammatory disease that affects the joints of the hands and feet and leads to disability.
- A diagnosis of rheumatoid arthritis is associated with elevated levels of blood bio-markers of oxidative stress and with reduced blood levels of antioxidants that normally neutralize harmful free radicals [Sahebari 2019].
- For example, blood levels of the selenium-dependent antioxidant enzyme glutathione peroxidase are notably lower in rheumatoid arthritis patients than in healthy controls [Sahebari 2019].
Mixed Results from Selenium and RA Clinical Trials
Some studies have shown reduced inflammation in rheumatoid arthritis patients taking a selenium supplement, as evidenced by reduced swelling and stiffness of the joints as well as by less severe pain [Sahebari 2019].
Other studies have not shown a statistically significant effect of selenium supplementation on the symptoms of rheumatoid arthritis [Sahebari 2019].
The conflicting results of clinical trials are thought to be related to differences in the types and dosages of selenium used in the experiments [Sahebari 2019].
The Form and the Dosage of the Selenium Supplement
Form
In a comparative study, Richie et al [2014] have shown significant reductions in bio-markers of oxidative stress following supplementation with selenium-enriched yeast supplements (but not with 100% selenomethionine supplements) in healthy men.
Selenium-enriched yeast, also known as high-selenium yeast, contains up to 20 species of selenium in addition to the selenomethionine species. Recent selenium fractionation research has shown that supplementation with a patented selenium yeast supplement resulted in structural confirmation in plasma of the selenium species Se-methyl-selenocysteine, a known anti-cancer substance [Ward-Dietrich 2020].
Dosage
The daily dosage of supplementary selenium (preferably taken in a selenium-enriched yeast supplement) depends on how much selenium each individual is getting in his or her diet.
Selenium researchers suggest that there is a U-shaped relationship between selenium status and health outcomes. A graph of the U-shaped relationship shows that the risk of disease increases in individuals whose serum/plasma selenium concentrations are below 100 micrograms per liter or whose serum/plasma selenium concentrations are higher than 170 micrograms per liter [Rayman 2012, figure 3].
Selenium blood tests can tell us which daily dosage – 50 micrograms, 100 micrograms, 200 micrograms – we need to achieve a serum selenium status within the 100-170 microgram per liter range.
Bottom Line: Selenium Intake/Status and Rheumatoid Arthritis
Turrubiates-Hernández et al [2020] make the following points in a review of the medical journal literature about the relevance of selenium status in rheumatoid arthritis patients.
- RA patients commonly have lower blood selenium concentrations than healthy individuals do.
- Adequate selenium is necessary for the formation of the antioxidant enzymes that help to regulate the patients’ oxidative and inflammatory state.
- It may be important to discuss the effects of geographical region, medications, and genetic polymorphisms on the RA patient’s selenium status.
- We need more clinical trials of the effect of various forms and dosages of selenium supplementation on the symptoms of rheumatoid arthritis.
- We need to keep in mind the U-shaped relationship between selenium status and good health.
Sources
Office of Dietary Supplements. Selenium. National Institutes of Health. 2020. Retrieved from https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/#h4.
Rayman MP. Selenium and human health. Lancet. 2012 Mar 31;379(9822):1256-68. doi: 10.1016/S0140-6736(11)61452-9.
Richie JP Jr, Das A, Calcagnotto AM, Sinha R, Neidig W, Liao J, Lengerich EJ, Berg A, Hartman TJ, Ciccarella A, Baker A, Kaag MG, Goodin S, DiPaola RS, El-Bayoumy K. Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial. Cancer Prev Res (Phila). 2014 Aug;7(8):796-804.
Sahebari M, Rezaieyazdi Z, Khodashahi M. Selenium and Autoimmune Diseases: A Review Article. Curr Rheumatol Rev. 2019;15(2):123-134.
Stoffaneller R, Morse NL. A review of dietary selenium intake and selenium status in Europe and the Middle East. Nutrients. 2015 Feb 27;7(3):1494-537.
Turrubiates-Hernández FJ, Márquez-Sandoval YF, González-Estevez G, Reyes-Castillo Z, Muñoz-Valle JF. The Relevance of Selenium Status in Rheumatoid Arthritis. Nutrients. 2020 Sep 30;12(10):3007.
Ward-Deitrich CL, Whyte E, Hopley C, Rayman MP, Ogra Y, Goenaga-Infante H. Systematic study of the selenium fractionation in human plasma from a cancer prevention trial using HPLC hyphenated to ICP-MS and ESI-MS/MS. Anal Bioanal Chem. 2020 Nov 2. doi: 10.1007/s00216-020-02988-9. Epub ahead of print.
Yu N, Han F, Lin X, Tang C, Ye J, Cai X. The Association Between Serum Selenium Levels with Rheumatoid Arthritis. Biol Trace Elem Res. 2016 Jul;172(1):46-52.
The information presented in this review article is not intended as medical advice and should not be used as such.
25 December 2020