Most Doctors Won’t Tell You About Selenium’s Benefits

By ratmaner @ Shutterstock.com

The benefits of selenium in your diet are many, but have you heard about them from your doctor? It’s rare that a doctor will discuss supplementation or diet with a patient, but there are some doctors who do. It’s important that you always get the full picture. One doctor who is dedicated to encouraging a preventative lifestyle, i.e. one that seeks to prevent illness before it begins, rather than treat it afterward, is Dr. Joseph Mercola. He explains on his blog, Mercola.com, the benefits of selenium in one’s diet, writing:

Selenium is an essential trace mineral that plays a unique and important role in a variety of biological functions. Your body cannot make selenium, so it’s important to get it from your food. It’s a major component in more than two dozen proteins that play crucial roles in a variety of functions, including thyroid hormone metabolism, DNA synthesis and reproduction.¹Selenium is also an antioxidant, which means it helps protect the body against free radicals and reactive oxygen species (ROS). It exists in two forms: inorganic and organic, both of which are found in dietary sources — including the organic form in animal tissue.Like most compounds, your body requires an optimal amount of selenium, which means that more is not better. There is some evidence to suggest that high serum concentrations can adversely affect glycemic control.² This means that individuals who have Type 2 diabetes or are at risk for Type 2 diabetes should measure serum concentrations before considering using a selenium supplement.When your body has optimal levels of selenium, it can help improve biological functioning, which in turn has a positive effect on antiaging, heart disease, cognitive decline and viral load progression.

Antioxidant Has Antiaging Benefits

The signs of aging you can visibly see in your skin and experience in your body are the result of molecular and immune system changes, increased susceptibility to environmental stressors, metabolic imbalance and disease that may happen as you age.³ These effects are the result of an imbalance between oxidative defense and ROS damage. Stem cell exhaustion, epigenetic alterations and changes in mitochondrial renewal also affect aging.

While signs of aging are common, there are steps you can take to help mitigate these effects. Maintaining optimal levels of nutrients and micronutrients is one of those steps. A review⁴ in 2019 showed the effect selenium has on the aging process occurs in part through the role it plays in selenoproteins, which are necessary for the expression of several important antioxidants.⁵Selenium is used in the expression of five separate glutathione peroxidases,⁶ which are responsible for reducing damage from ROS. These and other selenoprotein compounds play powerful roles as antioxidants, reducing the inflammation triggered by ROS and prolonging telomere length, which is the protective cap on the end of DNA strands.⁷When telomeres shorten to a critical length after division, the cells either die or stop dividing. These actions play a vital role in aging and some researchers suggest that supplementing with selenium, especially in the elderly, may be of “great significance” as a strategy for the prevention of age-related diseases.⁸

Low Selenium Raises Risk of Heart and Thyroid Disease

Obesity is a significant risk factor for heart disease. One study published in March 2021^9,10 found that adding selenium to the diet in an animal model helped protect against obesity and increased the healthy lifespan of the animals. The researchers were also interested in whether selenium could have the same beneficial effect on metabolism as restricting the amino acid, methionine.Selenium supplementation in this animal model provided the same protection against weight gain as restricting methionine, and dramatically reduced levels of the energy regulating hormones IGF-1 and leptin. The results suggested that supplementing with selenium had nearly the same effect as a diet restricted in methionine.¹¹ But selenium may also have a direct impact on your cardiovascular system.Scientists have been studying the effect of selenium on the cardiovascular system for decades, after finding that the disease was more prevalent in areas of the world where there were low serum selenium concentrations, such as in eastern Finland.¹²One meta-analysis¹³ in 2006 looked at observational studies that evaluated selenium serum concentrations and found they were inversely associated with the risk for coronary heart disease. The important aspect of this study is the researchers measured serum concentration of selenium and did not rely on an evaluation of supplementation alone.In 2013, a Cochrane Database Systematic Review¹⁴ concluded that there was limited evidence to support selenium supplementation to prevent heart disease. However, data from the studies showed most participants had a baseline or mean selenium serum concentration between 70 and 150 nanograms per milliliter (ng/mL), which is the normal concentration found in human blood serum.¹⁵In other words, it appeared supplementing with selenium was not effective when blood serum concentrations were already within the normal value. Another study¹⁶ published in 2020 also evaluated serum selenium levels and found those in the high range of the reference value had a decreased risk for cardiovascular disease and mortality.Optimal levels of selenium may also help individuals experiencing heart failure. One study¹⁷ found serum levels of selenium were independently associated with exercise tolerance in patients with heart failure and deficiency was linked to a 50% higher mortality rate.Thyroid hormones also influence the cardiovascular system, and may induce or worsen heart disease, including heart failure and atherosclerotic vascular disease.¹⁸ Several studies have demonstrated that supplementation with selenium in hyper- and hypothyroidism is associated with improvement.^19,20,21