Selenium Status and Mortality and Type 2 Diabetes

Higher serum selenium concentrations are associated with a statistically significant 31% lower all-cause mortality and a statistically significant 34% lower heart disease mortality in individuals with type-2 diabetes [Qiu 2021].

This is the conclusion of researchers who conducted a relatively large cohort study of patients with diabetes with a long follow-up period. They analyzed the data from 3199 American adults with type-2 diabetes; the average follow-up period was 12.6 years [Qiu 2021].

During that follow-up period, 1693 deaths were documented, including 425 heart disease deaths [Qiu 2021].

Highest Quartile of Serum Selenium Compared to Lowest Quartile

Individuals in the highest quartile of serum selenium concentration had significantly lower all-cause mortality rates and significantly lower heart disease mortality rates when compared with individuals in the lowest quartile of serum selenium concentration [Qiu 2021]. read more

Achieving Optimal Plasma Selenium Status

Hurst et al. administered 50-mcg, 100-mcg, or 200-mcg of selenium daily for ten weeks to 119 healthy men and women aged 50–64 years living in the United Kingdom.

Facial mask
A healthy immune system depends upon an optimal selenium status to promote the bio-synthesis of antioxidant selenoproteins.

The researchers were testing the effect of the different daily dosages on plasma selenium status and plasma selenoprotein P status. They used a pharmaceutical-grade high-selenium yeast preparation with a documented 88.7% absorption [Bügel 2004].

The men and women in the study had a daily dietary selenium intake of approximately 55 mcg/day.  Intakes of selenium in the United Kingdom had fallen from a mean of 60 mcg/day in 1991 to a minimum of 30 to 40 mcg/day in 1995–2000; in 2010, the mean intake was 48–58 mcg/day [Hurst 2010]. read more

Plasma Selenoprotein P Levels and the Risk of Cardiovascular Disease

Research conclusion: “The 20% with lowest SELENOP concentrations in a N orth European population without history of cardiovascular disease have markedly increased risk of cardiovascular morbidity and mortality” [Schomburg 2019].

Heart attack
Selenoprotein-P deficiency predicts cardiovascular disease and death. Low selenium intakes result in sub-optimal bio-synthesis of selenoprotein P in the liver. Now, research shows that low selenoprotein P concentrations are associated with increased risk of cardiovascular disease and mortality.

This is the conclusion from the Malmö Preventive Project, a population-based prospective cohort study in southern Sweden, that examined the relationship between plasma selenoprotein P status and 1) risk of all-cause mortality, 2) risk of cardiovascular mortality, and 3) risk of a first cardiovascular event in 4366 study participants.

Note that this was a study done with study participants who had no history of cardiovascular disease. It was truly a study of the relationship between selenium status and the risk of heart disease. read more

Selenium Supplementation and Anti-Ageing Effects

The development of ageing-related diseases seems to be closely related to the extent of damage inflicted on the cells by oxidative stress. Researchers define oxidative stress as damage to proteins, nucleic acids, and lipids caused by an imbalance between harmful reactive oxygen species (frequently referred to as free radicals) and the body’s antioxidative defenses [Alehagen 2021].

Elderly couple on the beach
We want to stay as young as possible as late in life as possible. Ensuring that we have an optimal intake of selenium is associated with protection against several aspects of ageing.

A 2021 review of the relevant research literature reveals the following findings [Alehagen 2021]:

-Optimal selenium status is necessary for the synthesis of the antioxidant seleno-enzymes: the glutathione peroxidases and the thioredoxin reductases.

-Selenium deficiency in elderly individuals seems to increase the risk of developing age-related diseases: chronic inflammation, cardiovascular disease,  cancer, and neurodegenerative diseases. read more

Selenium and Kidney Function

Here are the main points from a recent review article on the topic of aging and exposure to heavy metals and kidney function:

Kidney cross section
Professor Jan Aaseth and his colleagues have reviewed the research literature about the response of the aging kidney to environmental toxicants like mercury, cadmium, and lead. Selenium may have a protective effect in that it binds to and sequesters the harmful heavy metals and also serves to reduce the level of oxidative stress.

The efficiency with which the kidneys remove waste and excess fluid from the blood declines with age in individuals who are older than 50–60 years.

  • Exposure to metal pollutants may be detrimental to the kidneys of normal healthy adults and exacerbates the functional decline of the kidneys in seniors. Given the prevalence of these heavy metal toxicants in the environment, it is nearly impossible for people to avoid exposure.
    • Studies have shown that exposure to mercury, cadmium, and/or lead is associated with an increase in the incidence and the severity of kidney disease in elderly individuals. There is some reason to think that adequate selenium status helps to protect against the damage of heavy metal toxicants.
    • Unfortunately, the early signs of kidney dysfunction often go unnoticed.
    Mercury, Cadmium, Lead – Difficult to Avoid

    Prof. Aaseth et al. write that toxic metals are so abundant in the environment that it is almost impossible for humans to avoid contact with them. read more

    Low Selenium Status and Autoimmune Diseases

    Selenium is an essential trace element, essential in the sense that our bodies cannot synthesize it, and we must get what we need of it in our diets.

    Elderly people
    Professor Schomburg distinguishes between selenium substitution – supplying selenium to correct a nutritional deficit – and selenium supplementation – supplying selenium on top of a sufficient baseline status for therapeutical purposes. Here, elderly people with joint pain.

    Suboptimal intakes of selenium, i.e., intakes below the recommended intake levels, are associated with increased disease risks, in particular increased risk of autoimmune diseases, chronic diseases, inflammation, etc.

    Unfortunately, the health risks of selenium deficiency are often neglected. Here are some facts:

    • Preventable endemic diseases are known in regions with selenium deficiency, e.g., in certain parts of China.
    • Sufficiently high selenium status is a prerequisite for adequate immune system response.
    • Individuals living in regions with selenium-poor soil, women who are  pregnant, individuals with autoimmune thyroid disease, and individuals with a severe illness, e.g. COVID-19, are known to have sub-optimal selenium intakes and status.
    • Improved dietary choices and/or selenium supplementation are efficient ways to avoid severe selenium deficiency.

    These are the major points in a recent journal article published by Professor Lutz Schomburg, Charité–Universitätsmedizin Berlin, Freie Universität Berlin, and Humboldt Universität zu Berlin.

    Selenium and Selenoproteins

    The micronutrient selenium is a component of the amino acid selenocysteine, which is itself an essential part of some 25 selenoproteins identified in human biology. Some selenoproteins are known to be essential for life; accordingly, they are preferentially synthesized and distributed. The brain, for example, has high priority for selenium in times of scarcity. read more

    Covid-19 and Selenium and Coenzyme Q10

    The individual’s status of selenium and Coenzyme Q10 may be a decisive factor in his or her immune system’s response to the SARS-CoV-2 virus that causes the acute respiratory distress of a Covid-19 infection.

    Corona virus
    A research review shows that selenium and CoQ10 supplementation has positive effects on the free radical-induced oxidative stress and the inflammation associated with patients with COVID-19 disease.

    In particular, immune system cells require adequate selenium and Coenzyme Q10 to protect against oxidative stress and to modulate the inflammatory effect.

    This is the conclusion of the authors of a 2021 review of the relevant research literature [Hargreaves & Mantle].

    Iain R. Hargreaves, a biochemistry faculty member in the Pharmacy and Biomolecular Sciences Department of the Liverpool John Moores University, together with the medical doctor David Mantle, has written that adequate selenium status and adequate Coenzyme Q10 status may be important factors: read more

    What is an Adequate Selenium Status?

    Many people in the world live in regions with selenium-poor soil and, consequently, with selenium-poor food. The body cannot synthesize selenium, which is an essential non-metal trace element that we need in small amounts. A recent review of selenium status and the risk of cardiovascular disease suggests that serum selenium status below 100 mcg/L is associated with increased risk of heart disease, with reduced exercise capacity, with reduced quality of life, and with worse prognosis [Al-Murbarak].

    • Low intakes of selenium mean low selenium status.
    • Sufficient selenium is required for the formation of the amino acid selenocysteine, which is, in turn, an essential component of selenoproteins.
    • Low selenium status over longer periods of time can put individuals at greater risk of cardiovascular disease, cancer, and autoimmune thyroid disorders.
    • Adequate selenium intake and status are necessary for good immune function and protection against infectious diseases.Doctors' conference
    • Particularly vulnerable to have low selenium status are individuals who are vegetarians and vegans, pregnant and breastfeeding women, overweight or obese individuals, HIV-patients, kidney-dialysis patients, and individuals on parenteral nutrition as well as individuals living in selenium-poor regions.

    Where is selenium status likely to be low?

    Stoffaneller and Morse conducted a comprehensive study – 143 references – of selenium status in Europe, the UK, and the Middle East. They concluded that selenium intake and status are generally suboptimal in European and Middle Eastern countries, with somewhat more variation in the Middle East. They reported that suboptimal selenium status is widespread throughout Europe and the UK, with Eastern European countries having lower selenium intakes than Western European countries. In the Middle Eastern countries, they found varying results, which were possibly caused by different food habits and different imports in different regions and within differing socioeconomic groups [Stoffaneller & Morse]. read more

    Pharmacokinetics of Oral Selenium-Enriched Yeast Supplements

    The Danish researchers Niels Hadrup and Gitte Ravn-Haren have published a comprehensive study of the absorption, distribution, metabolism, and excretion of selenium obtained from food and from nutritional supplements [Hadrup 2021].

    Selenium supplements come in many forms, both organic and inorganic. The advantage of the selenium-enriched yeast preparations is that they contain 20-30 different species of selenium in addition to selenomethionine. Some of these selenium species may have important biological effects.

    Here we summarize their findings with respect to selenium in selenium-enriched yeast supplements. We do this for two reasons:

    Absorption of selenium from selenium-enriched yeast preparations

    In a 2008 paper, researchers reported having given healthy elderly individuals 100, 200 or 300 mcg selenium in a selenium-enriched preparation daily for a period of 5 years. The supplementation resulted in mean plasma levels of 165, 221, and 260 mcg/L, respectively. In the control group, given a placebo for 5 years, the plasma selenium concentration was 92 mcg/L [Ravn-Haren 2008]. read more

    Selenium and Patients with Autoimmune Thyroid Disease

    Sufficient selenium status is necessary for good thyroid health.

    A woman's neck
    Selenium-containing drugs are effective for treating patients with autoimmune thyroid disorders [Zuo 2021].
    Zuo et al [2021] have investigated selenium status and the effects of selenium supplementation in patients with autoimmune thyroid disease.

    They analyzed the data from 17 journal articles based on studies of 1,911 subjects. Their meta-analysis results showed the following statistically significant associations:

    • Serum free triiodothyronine (FT3) levels in patients were reduced after selenium supplementation compared to placebo treatment.
    • Serum free thyroxine (FT4) levels and anti-thyroid peroxidase antibody (TPOAb) levels were reduced after selenium supplementation compared to placebo treatment.
    • Anti-thyroid peroxidase antibody (TPOAb) levels were decreased after selenium supplementation compared to placebo treatment.

    However, the thyroid stimulating hormone (TSH) levels
    and the anti-thyroglobulin antibody (TGAb) levels were not significantly different between the selenium treatment group and the control group.

    The researchers concluded that selenium-containing drugs were effective in treating patients with autoimmune thyroid disease and greatly reduced
    the levels of free triiodothyronine, free thyroxine, and anti-thyroid peroxidase antibody in these patients. read more