Selenium and Graves’ Hyperthyroidism

Thyroid disease. What is the role of the micronutrient trace element selenium in thyroid disease? The thyroid gland is the organ in the body that contains the greatest amount of selenium per gram of tissue [Wang 2023]. Even in times of low dietary selenium intakes, the thyroid gland has high priority for the supply of selenium in the body [Schomburg 2020].

Endocrine system depicted
The thyroid gland is part of the endocrine system. It plays an important role in the body’s metabolism. It has high priority for the supply of selenium in the body.

Dietary selenium intakes vary considerably from region to region in the world. There are large differences in the soil content of selenium and in the factors that influence the bioavailability of selenium to plants. As a consequence, individuals’ plasma/serum selenium status varies accordingly [Winther 2020]. Thus, widespread sub-optimal selenium status has been reported throughout Europe, the United Kingdom, and the Middle East [Stoffaneller & Morse 2015]. read more

Selenium and Metabolic Syndrome

Metabolic syndrome – according to the American Heart Association, metabolic syndrome is a medical condition that can lead to heart disease, diabetes, stroke, and other health problems. The diagnosis of metabolic syndrome is met whenever a patient has three or more of the following five risk factors [What 2023]:

The risk of metabolic syndrome increases with increasing age, with being overweight or obese, and with increased insulin resistance.

High blood pressure

  • High blood sugar
  • High blood levels of triglycerides
  • Low blood levels of HDL cholesterol
  • Large waist circumference
  • In particular, metabolic syndrome puts the patient at increased risk of developing atherosclerosis, the condition in which the build-up of fatty deposits on the inner walls of arteries impedes blood flow and eventually restricts the flow of blood to the heart [What 2023]. read more

    Selenium Deficiency and Immune Function

    Less systemic inflammation. Better immune function. Selenium is an essential trace element. Our cells cannot synthesize it. We must get it as a part of our diets. Adequate intakes are necessary for optimal immune system function.

    Man in wheelchair at the beach
    Autoimmune diseases develop when our own immune system malfunctions and attacks our cells. Then we suffer from autoimmune thyroid disorders, lupus, multiple sclerosis, psoriasis, rheumatoid arthritis or a hundred other autoimmune diseases.

    Unfortunately, many of us live in regions with selenium-poor soil and selenium-poor crops and fruits. We do not get sufficient selenium from our food [Stoffaneller & Morse 2015]. Adequate selenium intake and status are vital. There are increased health risks associated with selenium deficiency.

    What Defines Selenium Deficiency?

    Data from the BIOSTAT-CHF observational cohort study indicate that serum selenium concentrations under 70 mcg/L constitute a deficiency status. Serum selenium concentrations under 100 mcg/L constitute a sub-optimal status [Bomer 2020]. read more

    Selenium and Hypothyroidism

    In the CATALYST study, researchers found that selenium supplements and placebo supplements improved the quality of life of patients with hypothyroidism to an equal extent. Accordingly, the researchers have now emphasized a need for more research into the effect of selenium supplementation on immune system function, on oxidative stress, and on low-grade inflammation in patients with thyroid diseases [Larsen 2024].

    Thyroid system depicted
    Depiction of the thyroid system. Attribution: Mikael Häggström, Public domain, via Wikimedia Commons. The CATALYST study (Chronic Auto-immune Thyroiditis Quality of Life Selenium Trial) sought to establish whether selenium supplementation improves quality-of-life in patients with autoimmune thyroiditis .

    The CATALYST study was a multi-center randomized, double-blinded, placebo-controlled clinical trial conducted in Denmark. The study participants were patients aged 18 or more years with serum thyroid peroxidase antibody (TPOAb) levels equal to or greater than 100 IU/mL. 82% of the study participants were women [Larsen 2024]. read more

    Selenium and Human Longevity

    The absorption of dietary and supplemental selenium has an important and positive influence on human longevity. Selenium researchers have called selenium a “longevity element.” The selenoenzymes and selenoproteins of which selenium is an essential component have antioxidant, anti-inflammatory, and anti-cancer activity in humans [Li 2024].

    Great Wall of China
    Typically, China has many regions with selenium-poor soil and selenium-poor foodstuffs. Some regions, however, do have selenium-rich soil and selenium-rich crops and fruits. One such region is characterized by the longevity of its residents. Selenium seems to be a factor in anti-aging.

    Maintaining selenium absorption and metabolism at an optimal physiological state seems to be one of the primary factors for good health and longevity of the elderly people. In particular, scientific studies have shown that selenium intake and status play an important role in the incidence and progression of some chronic diseases [Li 2024]:

    • Cancer: inducing tumor cell apoptosis, reducing the mutagenicity of carcinogenic factors, prolonging the cell division interval, and slowing proliferation of malignant cells
    • Heart failure: improving exercise tolerance, reducing mortality rate, and improving quality of life
    • Heavy metals: binding to mercury, sequestering mercury, reducing mercury’s biological availability and reducing the damage to the kidney caused by exposure to heavy metals
    • Antioxidant effects: restoring the antioxidant defense system of the body
    Selenium-Rich Soil in a Chinese Longevity Township

    Bama Yao Autonomous County is the only longevity township in China that is globally recognized as having a continuously growing longevity population. In 2020, Bama had 102 residents over 100 years old. The number had increased from the 2000 census (74 residents over 100 years of age) and the 2010 census (82 residents over 100 years of age). Bama has relatively stable genetic and geographic factors and a relatively stable dietary culture [Li 2024]. The proportion of centenarians is nearly six times greater than the international standard proportion [Zhang 2023]. read more

    Selenium May Reduce the Risk of Heart Disease and Some Cancers

    Reduced risk of heart disease and reduced risk of some cancers. Increasing the daily intake of selenium among individuals with low selenium status may reduce the risk of cardiovascular disease and some cancers. The available data seem to show that most adults in the Nordic and Baltic countries, with the exception of adults in Finland, have low selenium intakes and low selenium status [Alexander & Olsen 2023].

    Jan Alexander
    Prof. Jan Alexander, MD, PhD, Norwegian Institute of Public Health in Oslo, says: There are various factors that influence cardiovascular disease mortality and cancer incidence: diet, lifestyle, genetics, inter alia. The impact of these factors varies from one Nordic country to the next.

    Selenium is an essential trace element. The human body cannot synthesize it. It must come from the diet and supplements. Selenium is a vital component of selenoproteins that are critical to normal health and physiological functioning. This is the fundamental message from a 2023 selenium scoping review conducted for the Nordic Nutritional Recommendations 2023 [Alexander & Olsen 2023]. read more

    Selenium Delays Cognitive Decline

    In the Swedish KiSel-10 clinical trial, the study participants had an average age of 78 years at the start of the study [Alehagen 2013]. Their serum selenium concentration at baseline was at a deficiency level (mean: 67.1 mcg/L).

    Woman meditating
    Diet, exercise, and meditation are all important to good brain health. Dietary and supplemental selenium crosses the blood-brain barrier. Supply of selenium to the brain has a higher priority than supply to other organs. Low selenium status is associated with cognitive decline.

    Moreover, the low selenium status of the elderly Swedish citizens was significantly associated with relatively high mortality risk [Alehagen 2016]. Daily supplementation with 200 mcg of a selenium-enriched yeast preparation together with 200 mg of Coenzyme Q10 raised the study participants’ serum selenium levels to 210 mcg/L and reduced the risk of cardiovascular mortality [Alehagen 2022a].

    The four years of joint supplementation were associated with the following positive health outcomes: read more

    Selenium and Selenoprotein P and Mortality

    Higher all-cause mortality and higher mortality due to cancer, cardiovascular disease, gastrointestinal diseases, and respiratory disorders are associated with lower serum selenoprotein P concentrations in older German adults [Schöttker 2024].

    Operation table
    Death from all causes and death specifically caused by cancer, cardiovascular disease, gastrointestinal diseases, and respiratory disorders are strongly associated with low serum concentrations of the selenium-dependent selenoprotein P.

    In plain English, lower blood concentrations of the selenium-dependent selenoprotein P are significantly associated with a higher risk of degenerative disease progression and with dying. Moreover, the data from the German study show that the risk of dying associated with low blood Selenoprotein P levels was more than double in men compared to women [Schöttker 2024].

    In the Esther Study, German researchers assessed the association of measurements of serum Selenoprotein P concentrations with all-cause and cause-specific mortality data. They measured serum Selenoprotein P at baseline and again at a 5-year follow-up in 7,186 and 4,164 participants, respectively [Schöttker 2024]. read more

    Selenium Intakes and Health Outcomes

    Selenium and good health. How much do we need? How do we get it? Generally speaking, our family and friends do not know just how important selenium is to good health. Our bodies cannot synthesize selenium. We are dependent upon food for an adequate daily intake of this essential trace element.

    Salmon rich in selenium
    Depending upon where we live, the selenium content of our food may be too low. Wang et al [2023] estimate that approximately one billion people worldwide lack sufficient selenium in their diet.
    In many regions of the world, the soil and the foodstuffs have a poor selenium content. Accordingly, the daily intake of selenium varies considerably. Many people have an inadequate supply and thus risk poor health outcomes as a result. For example, in much of Europe, the UK, and the Middle East, there are widespread reports of suboptimal selenium status. Supplementation is necessary in selenium-poor regions [Stoffaneller & Morse 2015]. read more

    Selenium Status and Mortality Risk

    Mortality and morbidity. As we get older, we start to think about ways to reduce the risk of an early death. We want to reduce the risk of living out our lives in ill health.

    Zion National Park in the USA
    Pictured here: A creek in the Zion National Park in Utah.

    We think about diet, exercise, 10,000 steps a day, hobbies, social contact. But, do we think about our selenium intake and status? Now, some large survey studies conducted in the US have shown that higher selenium status is significantly associated with lower mortality.

    Each year, the National Health and Nutrition Examination Survey (NHANES) in the United States conducts surveys that focus on different population groups or health topics. This week, we present data from studies of selenium status and mortality.

    Selenium Status and Type 2 Diabetes

    Qiu et al examined the data from 3199 adults with type 2 diabetes. Their analysis showed that higher serum selenium concentrations are associated with lower all-cause mortality and lower heart disease mortality among individuals with type 2 diabetes [Qiu 2022]. read more