Selenium is an essential mineral for humans and animals. Selenium deficiency can occur at low dietary intake levels. Sub-optimal and deficiency levels of selenium are associated with negative health outcomes [Wesolowski 2022; Bomer 2020].
Selenium is best known for its biological role as a component of antioxidant selenoproteins, in particular the glutathione peroxidases and the thioredoxin reductases. These antioxidant enzymes protect against
oxidative stress, reduce the extent of systemic inflammation, and regulate
cell death [Wesolowski 2022].
In addition, selenium as a constituent of some 25 known selenoproteins has a variety of physiological functions beyond the antioxidant capabilities. One of the more interesting roles of selenium is the promotion of mitochondrial bio-genesis in skeletal muscle [Wesolowski 2022].
Note: Mitochondrial bio-genesis refers to the process of forming new or bigger mitochondria. The bio-genesis involves the division and growth of existing mitochondria. It is an essential process for ATP energy generation in the muscle cells and tissues.
Selenium Supplementation and Mitochondria
In a 2022 review, Wesolowski et al investigated the influence of selenium on mitochondrial bio-energetics and muscle function. The mitochondria are organelles in the cells. The mitochondria play an indispensable role as generators of ATP energy in a process called oxidative phosphorylation.
Animal study
Very little research has been done on the extent to which selenium supplementation can increase skeletal muscle mitochondria. A study in horses has shown that selenium supplementation is associated with greater mitochondrial volume density. However, the research showed no evidence of an improvement in mitochondrial function [reported in Wesolowski 2022].
Human study
In a study enrolling young male human study participants, researchers administered 180 mcg/day of selenomethionine while the young men did endurance training for 10 weeks. The selenium supplementation during the endurance training caused a greater increase in the size of the individual skeletal muscle mitochondria than did endurance training alone [reported in Wesolowski 2022].
Wesolowski et al interpreted this outcome to mean that the selenium supplementation helped to preserve existing mitochondria. They speculated that selenium’s antioxidant protecting cells and organelles from oxidative
Stress may explain the increases in the size and number of skeletal muscle mitochondria associated with selenium supplementation [Wesolowski 2022].
One way or another – the mechanism is not known with certainty – selenium supplementation seems to induce the process of increasing the number of mitochondria in cells. Moreover, in cell culture studies, researchers have shown that selenium supplementation is associated with improved mitochondrial respiratory capacity [reported in Wesolowski 2022].
Conclusion: Selenium and Mitochondrial ATP Energy Generation
There is very limited direct research literature on the effects of selenium on skeletal muscle mitochondria.
Selenium is essential for its antioxidant roles.
Some studies indicate that selenium may improve mitochondrial bio-genesis.
The extent of the impact of selenium on mitochondrial function may vary according to tissue type, exercise intensity and exercise duration, and the selenium species in a given selenium supplement.
We need more studies of the ways in which selenium affects skeletal muscle health and mitochondrial function.
Sources
Bomer N, Grote Beverborg N, Hoes MF, Streng KW, Vermeer M, Dokter MM, IJmker J, Anker SD, Cleland JGF, Hillege HL, Lang CC, Ng LL, Samani NJ, Tromp J, van Veldhuisen DJ, Touw DJ, Voors AA, van der Meer P. Selenium and outcome in heart failure. Eur J Heart Fail. 2020 Aug;22(8):1415-1423.
Wesolowski LT, Semanchik PL, White-Springer SH. Beyond antioxidants: Selenium and skeletal muscle mitochondria. Front Vet Sci. 2022 Dec 1;9:1011159
The information contained in this review article is not intended as medical advice. It should not be used as such.