Serum Selenium Levels Predict Breast Cancer Prognosis

Research done in southern Sweden shows that three blood biomarkers of selenium availability correlated inversely with mortality from breast cancer. The lower the three selenium biomarker levels, the higher the mortality [Demircan 2021].

Breast cancer pink ribbon
Assessment of selenium status at the time of breast cancer diagnosis identifies patients at exceptionally high risk for a poor prognosis. They are breast cancer patients with low levels of selenium, selenoprotein P, and glutathione peroxidase in their blood.

The blood biomarkers are:

  • Total selenium
  • Selenoprotein P
  • Glutathione peroxidase 3

Breast cancer patients with blood concentrations of these three selenium biomarkers in the highest quintile had significantly better chances of survival compared with patients whose blood levels of these substances were in the lowest quintile [Demircan 2021].

Breast cancer patients with low selenium status according to these three biomarkers had the highest mortality risk with an overall survival probability of approximately 50% after 8 years. The difference in survival between the breast cancer patients in the lowest selenium quintile compared to breast cancer patients with at least one biomarker in the highest quintile was especially notable [Demircan 2021]. read more

Selenium Supplementation for Senior Citizens

Health benefits of daily supplementation of senior citizens with a combination of selenium and Coenzyme Q10:

  • improved heart function as shown on echocardiograms
  • reduced risk of death from heart disease
  • improved health-related quality of life
Professor Urban Alehagen
In the KiSel-10 Study, Prof. Urban Alehagen and the research team administered 200 mcg/day of selenium and 2 x 100 mg/day of Coenzyme Q10 for 48 months to elderly Swedish citizens whose serum selenium status at baseline was quite low (mean: 67.1 mcg/L). The duration of the study was 48 months. The benefits of the supplementation were improved heart function and reduced risk of death from heart disease.

The combined supplementation seems to work by reducing the extent of oxidative stress, systemic inflammation, and fibrosis in the study participants [Alehagen 2022a].

Now, data from the KiSel-10 Study show the following effects of the combined supplementation with respect to Fibroblast Growth Factor 23 concentrations in blood:

  • Supplementation decreased concentrations of FGF-23 hormones.
  • The study showed a relationship between the circulating level of the FGF-23 and atrial fibrillation.
  • The study showed an association between the concentration of FGF-23 and death from heart disease.
  • The study showed an effect of reduced FGF-23 levels on the risk of death from heart disease that is independent of the level of the cardiac wall tension bio-marker NT-proBNP.
  • There exists a close interrelationship between FGF-23 concentrations and kidney function.
Why are FGF-23 Concentrations Important?

Prof. Alehagen explains that FGF-23 is a hormone that is secreted into the blood circulation. One of its primary functions is the regulation of the vitamin D metabolism and of the phosphorous metabolism in the kidneys.

However, there seems to be an association between FGF-23 activity and cardiovascular mortality even in the absence of kidney disease. Experimental data show that FGF-23 may act as a mediator for cardiac hypertrophy, cardiac fibrosis, and cardiac dysfunction [Alehagen 2022b]. read more

Selenium and Toxic Metals and the Ageing Kidney

In individuals older than 50-60 years, the kidneys’ glomerular filtration rate decreases with increasing age. The glomerular filtration rate is a measure of how well your kidneys are working. In your kidneys, there are tiny filters (called glomeruli) that remove waste and excess fluid from the blood.

Jan Aaseth
Jan Aaseth is a Norwegian physician and professor who has done extensive research in endocrinology, toxicology, and medical biochemistry. Here we summarize his review of the relationship between selenium status, heavy metal toxicity, and the kidneys.

Exposure to toxic metals – mercury, cadmium, lead – can be detrimental to kidneys of normal adults. Accordingly, exposure to toxic metals can affect individuals with reduced glomerular filtration rates even more adversely.

Professor Jan Aaseth and a team of researchers have reviewed the available research data. Their findings show the following relationships [Aaseth 2021]:

Elderly Individuals More Susceptible to Toxic Metal Exposure

Healthy elderly individuals are capable, for the most part, of maintaining normal kidney function. However, especially after the age of 70 years, physiological changes occur in the kidneys. read more

Selenium Status and Covid-19 Patients

In cases of severe Covid-19 disease, patients have significantly lower concentrations of selenium and selenoprotein P and significantly higher levels of oxidative stress. That is to say, there is a more intense formation of harmful free radicals in patients with severe Covid-19 disease [Skesters 2022].

Corona virus
An adequate supply of selenium and zinc and vitamin D is essential for resistance to the corona viruses and to other viral infections. Here, Skesters er al show that Covid-19 patients have significantly lower levels of plasma selenium and selenoprotein P and significantly higher levels of oxidative stress.

Note: Oxidative stress is the bio-medical term for an imbalance between harmful free radical activity and protective antioxidant activity. Selenium is a key component of antioxidant selenoproteins such as the glutathione peroxidases and the thioredoxin reductases.

Role of Selenium and Selenoprotein P in Covid-19 Disease

Researchers have been investigating the role that selenium may play in reducing the severity and mortality of Covid-19 infections. Studies have shown a close relationship between low selenium status, Selenoprotein P deficiency, oxidative stress level, and Covid-19 disease incidence, severity, and prognosis [Skesters 2022]. read more

Antioxidant Action of Selenium and Selenoproteins

Antioxidants. Several selenoproteins play important roles as antioxidant enzymes in the protection of the cells and the mitochondria against the oxidative damage caused by harmful free radicals. Prominent among the antioxidant seleno-enzymes are the glutathione peroxidases and the thioredoxin reductases [Alehagen 2022].

Professor Urban Alehagen
Professor Urban Alehagen, the lead researcher on the KiSel-10 Study, estimates that a daily selenium intake of 110-150 mcg per day is necessary to achieve optimal expression of selenoprotein P, one of the most important selenoproteins in the plasma and the main transporter of selenium in the blood [Alehagen 2022].
Note: Oxidative stress is the bio-medical term for an imbalance in the relationship of 1) harmful free radicals, mostly of the reactive oxygen species, and 2) protective antioxidants, which should neutralize the harmful free radicals.

In many regions of the world, notably in much of Europe and the Middle East, there is selenium-poor soil and selenium-poor foodstuffs. In Sweden, for example, the average daily intake of selenium among senior citizens
is approximately 35 mcg/day, well below the amounts (110–150 mcg/day) needed for an optimal expression of the selenoprotein antioxidants [Alehagen 2022].
read more

Impact of Selenium Status on Ageing

Selenium is an essential trace element. Essential means that sufficient selenium is necessary for normal cell functioning and that our bodies cannot synthesize selenium for us. We must get it from our diets. Trace element means selenium is a micronutrient that is needed in very small quantities, in microgram quantities. It may be an important element to slow the ageing process.

Elderly couple
Selenium as a component in protective enzymes helps to keep us healthier longer in life. It helps to suppress oxidative stress and to decrease inflammation, to remove misfolded proteins, to decrease DNA damage, and to promote telomere length.

Sufficient selenium status plays an important role in the prevention of cardiovascular diseases, inflammation, and infections. Prof. Margaret P. Rayman, University of Surrey, estimates that serum/plasma selenium status of around 125 mcg/L is optimal for human health [Rayman 2020].

The beneficial work of selenium in the cells and tissues is done by selenoproteins that contain the amino acid selenocysteine in the active center. Among the selenoproteins known to have an antioxidant effect in the body are the glutathione peroxidases (GPX1-4 and GPX6) and the thioredoxin reductases (TXNRD1-3) [Alehagen 2021]. read more

Selenium Supplementation and Preeclampsia Risk

Selenium supplementation of pregnant women at a high risk of preeclampsia has shown beneficial effects on 1) serum selenium levels, 2) some metabolic profiles, 3) uterine artery pulsatility index, and 4) mental health, compared to placebo. The study compared the effect in 60 pregnant women of supplementation with 200 mcg/day for 12 weeks with the effect of placebo for the same period.

Pregnant woman
Preeclampsia is a serious hypertensive condition of pregnancy. It is associated with high risk of maternal and fetal morbidity and mortality. Selenium intake and status have been linked to the occurrence of preeclampsia.

The supplementation took place for 12 weeks starting in weeks 16 to 18 of pregnancy. No side effects related to the intake of 200 mcg of selenium per day by pregnant women at high risk of preeclampsia were reported throughout the duration of the study  [Mesdaghinia 2022].

Selenium Supplementation Compared to Placebo

How did the selenium supplementation compare with the placebo supplementation in the pregnant women? read more

Selenium Deficiency and Heart Failure

Heart failure – the inability of the heart muscle to pump a sufficient quantity of blood out to the body – is a debilitating disease, resulting in shortness of breath, congestion in the lungs, and pooling of blood in the lower extremities. Heart failure is equivalent to diminished quality of life.

Mitochondrion
Depiction of a mitochondrion. The mitochondria in our cells convert energy sources such as fatty acids, glucose, and ketones into ATP energy molecules. Sufficient intakes of micronutrients such as selenium, Coenzyme Q10, and zinc are important for mitochondrial energy production and for antioxidant protection of cells, lipids, proteins, and DNA.

The prognosis for heart failure is poor, and the available medical therapies for patients with heart failure are inadequate. New treatment strategies are needed [Mortensen 2015].

Yin et al have analyzed the data from 39,757 adults in a cross-sectional study from the 2005–2018 US National Health and Nutrition Examination Survey. Their findings suggest that high levels of combined dietary antioxidant micronutrients are associated with decreased prevalence of various forms of cardiovascular disease and that selenium has the greatest contribution to this association [Yin 2022]. read more

Selenium and Immune Function and DNA Repair

Selenium is a trace element essential for for DNA repair, for  good immune function, and for reduced mortality risk.

DNA double helix
Cell studies, animal models, and human clinical trials suggest that an optimal supply of selenium is required to enhance the process of DNA damage repair.

The Micronutrient Information Center maintained by staff members at the Linus Pauling Institute of the Oregon State University provides reliable information about the vitamins and minerals and trace elements used in nutritional supplements.

Today, I want to summarize the information that the Center provides about selenium and supplement that information with the latest scientific research.

An Introduction to Selenium and Selenoproteins

Selenium is a trace element that is essential that humans need for the proper functioning of selenium-dependent selenoproteins. Free selenium is rare in the body. Instead, the selenium in the body is typically a component of selenomethionine, selenocysteine, and methyl-selenocysteine. read more

Selenium Supplementation and Autoimmune Thyroiditis

Autoimmune thyroiditis is the umbrella term for various types of thyroiditis in which the immune system mistakenly attacks the thyroid gland.

Endocrine glands placement
The thyroid gland is the butterfly-shaped endocrine gland in the lower part of the neck. It plays an essential role in the regulation of our basic metabolism.

The result is often hypothyroidism, the insufficient functioning of the thyroid gland.

The two major types of hypothyroidism are Hashimoto’s disease and atrophic thyroiditis.

Thyroiditis is the medical term for inflammation of the thyroid gland.

Immune system disorder can also cause an overactive thyroid, called hyperthyroidism; Graves’ disease is the most common form.

Selenium Supplementation to Prevent Hypothyroidism

In a 2021 review article, Filipowicz et al assert that many European endocrinologists prescribe selenium supplements to autoimmune thyroiditis patients.

For example, a 2016 survey of 815 doctors (91% endocrinologists) has shown that almost 80% of the surveyed doctors prescribe selenium supplementation to autoimmune thyroiditis patients. The rationale for the selenium supplementation is the delay of the hypothyroidism or a decrease in thyroid antibodies [Filipowicz 2021]. read more