Posts

Posted on

Selenium Supplementation and Graves’ Disease

Low selenium status is associated with increased risk of Graves’ Disease. Graves’ Disease is an autoimmune disease of the thyroid. It is the most common cause of hyperthyroidism. It often results in an enlarged thyroid.

A 2018 meta-analysis of randomized controlled trials shows that adjuvant selenium supplementation may enhance the restoration of normal thyroid function in patients with Graves’ Disease [Zheng].

Graves’ Disease is the most common cause of hyperthyroidism in adults. It is characterized by below-normal serum TSH levels and increased serum levels of free thyroxine (FT4) and/or triiodothyronine (T3). The basal metabolic status of Graves’ Disease patients is accelerated; the result is an increase in the production of harmful free radicals and reactive oxygen species [Zheng].

Intra-cellular antioxidant enzymes such as superoxide dismutase (SOD), glutathione reductase, and glutathione peroxidase (GPx) protect against the cellular damage caused by oxidative stress. read more

Posted on

Selenium Supplementation and Glucose Metabolism

The evidence from a randomized controlled trial shows that 2.9 years of supplementation with 200 micrograms per day had no effect on insulin sensitivity and no effect on pancreatic beta-cell function compared with placebo [Jacobs 2019]. The evidence from randomized controlled trials does not support a role for selenium in the risk of developing type-2 diabetes [Kohler 2018].
The findings from a 2018 meta-analysis show no consistent evidence that selenium supplementation plays a role in the development of type 2 diabetes among adults.

Researchers at the University of Arizona in Tucson, home of the Arizona Cancer Center, identified a statistically significant direct relationship between selenium and Type-2 diabetes in observational studies but no statistically significant relationship in randomized controlled trials [Kohler 2018].

Note: Randomized controlled trials are the gold standard for scientific evidence in the bio-medical field. The randomization of the study participants should produce comparable groups and should eliminate accidental bias.  In observational studies, the researchers do not randomly assign the study participants to groups and do not decide which treatments each group receives or does not receive. read more

Posted on

Selenium Status and Heart Failure

Heart failure patients with low serum selenium levels are much more likely to be re-hospitalized and/or to die than are heart failure patients with serum selenium levels above 100 micrograms per liter.

A multi-national cohort study has shown that selenium deficiency in heart failure patients is associated with impaired exercise tolerance and with a 50% higher mortality rate [Bomer].

In-vitro studies of cultured human heart muscle cells from the heart failure patients show that  low selenium levels in the heart muscle cells are associated with impaired mitochondrial function [Bomer].

Recent information shows that up to 50% of heart failure patients suffer from some form of micronutrient insufficiency, e.g. selenium, zinc, iron, or iodine [Bomer].

Selenium: An Essential Micronutrient

Selenium intakes and status vary considerably from geographical region to region according to the content of selenium in the soil and in the food.

Sufficient intakes of selenium are necessary for important biological functions: read more

Posted on

Selenium Supplementation and Sperm Quality Parameters

Supplementation with selenium and with Coenzyme Q10 has beneficial effects on sperm count, sperm motility, and sperm morphology. There seems to be a special interrelationship between selenium and Coenzyme Q10 such that sufficient concentrations of each are needed for the optimal function of the other.

Data from two randomized controlled trials have shown that selenium supplementation has the following significant beneficial effects [Salas-Huertos]:

  • improved sperm volume and concentration
  • improved sperm motility
  • improved sperm morphology

Selenium supplementation at 100 micrograms per day for 3 months improved sperm motility and increased the chance of conception.  Selenium supplementation at 200 micrograms per day for 6 months improved semen volume, total sperm count and concentration, and sperm morphology [Salas-Huertos].

Data from five other randomized controlled trials have shown that Coenzyme Q10 supplementation is significantly associated with the following beneficial effects:

  • improved sperm count
  • improved sperm concentration
  • improved sperm motility
  • improved sperm morphology

The Coenzyme Q10 supplementation was most effective when the supplementation was in the range of 200 – 300 milligrams per day (in divided doses) for at least 3 months and especially after 6 months [Salas-Huertos]. read more

Posted on

Selenium Status and Prostate Cancer Risk

The light blue ribbon is the prostate cancer awareness ribbon. Along with skin cancer, prostate cancer is the most common cancer among American men. The American Cancer Society estimates that one man in nine will be diagnosed with prostate cancer during his lifetime. Research shows that blood selenium status within a specific range is associated with reduced risk of prostate cancer.

One of the big challenges in selenium research is the optimizing of the daily selenium intake to reduce the risk of prostate cancer. We need more research results to answer the following questions about the use of selenium supplements to reduce the risk of prostate cancer [Waters & Chiang 2017]:

  • What is the optimal formulation of the selenium supplement?
  • What is the correct daily dosage?
  • What is the range of baseline blood selenium concentrations that indicates a need for selenium supplementation?
  • What is the blood selenium level above which selenium supplementation will not reduce the risk of prostate cancer further?

The idea that selenium intakes and selenium status are an important determinant of prostate cancer risk began to receive considerable attention after University of Arizona Professor Larry Clark published the results of the Nutritional Prevention of Cancer Trial in JAMA in December 1996 [Clark 1996].

High-Selenium Yeast Supplements in the Nutritional Prevention of Cancer Trial

The Nutritional Prevention of Cancer Trial (NPCT) was a supplementation trial using 200 micrograms of a selenized yeast preparation or placebo for an average duration of 4.5 years.  The study participants were 1312 men and women with an average age 63 years. read more

Posted on

Selenium and Longevity and Ageing

There are notable regional variations in the blood selenium concentrations in senior citizens. The differences range from 66 micrograms per liter in Brazil and Turkey to 126 micrograms per liter in Japan.  Below 85 micrograms per liter is poor selenium status.  The desirable range is thought to be 125-135 micrograms per liter.

We want, all of us, to stay as young and healthy as possible as late in life as possible.  Ageing is inevitable.  How can we delay the onset of ageing’s bio-chemical and physiological consequences?

  • Physical exercise?
  • Caloric restriction?
  • Ingestion of micronutrients?

Selenium Status and the Health of Senior Citizens

The authors of a 2019 review article have found that, overall, there is an inverse correlation between age and blood selenium levels. Higher age is associated with lower blood selenium concentrations [Robberecht 2019].

Inadequate dietary intakes of selenium and poor selenium status (< 85 micrograms per liter in blood) may increase the risk of following harmful health outcomes [Robberecht]:

  • oxidative stress (= imbalance of harmful free radicals and protective antioxidants)
  • destruction of nerve cells (neurons)
  • dementia

Selenium Status and Biological and Social Factors

A variety of factors must be taken into consideration when we investigate the relationship between ageing and selenium intake and status.  There are, first of all, considerable regional variations in the availability of selenium in the soil and in foodstuffs [Stoffaneller & Morse]. read more

Posted on

Selenium For Cancer Treatment

Pre-clinical studies suggest that selenium supplementation in the right formulation and the right dosage may enhance the effects of chemotherapy for certain forms of cancer. Selenium may help to protect normal cells and tissues against the toxicities of chemotherapy drugs.  Selenium may enable the administration of higher than normal doses of the chemotherapy drugs.

Chemotherapy and radiation continue to be the major forms of treatment for many types of cancer. The considerable toxicity of these treatments to normal cells is a problem in cancer treatment and management.

Selenium’s Role in Cancer Prevention

Selenium supplementation has already been associated with statistically significant reductions in the risk of various cancers and pre-cancerous conditions:

Possible Role for Selenium in Cancer Treatment

Selenium supplementation may be valuable in the treatment of cancer as well as in the prevention of cancer.  Selenium has the ability to protect against the formation and progression of some cancer cells and also the ability to selectively target some existing cancer cells.

Moreover, it may be that selenium can work in synergy with conventional cancer therapies.  Pre-clinical research data suggest that selenium may in some instances protect normal cells and tissues against the toxic effects of conventional cancer treatments on the cells [Evans 2017]. read more

Posted on

Metabolic Changes After Supplementation with Selenium and Coenzyme Q10

Professor Urban Alehagen’s research has shown that there is a relatively high mortality risk in elderly Swedish subjects with low selenium intakes and low selenium status. Senior citizens in Sweden had, on average, serum selenium concentrations of 67.1 micrograms per liter. The same increased mortality risk seen in Sweden may be typical of other selenium-poor regions of the world as well.

There are clear differences in the metabolic profiles of elderly men who took 200 micrograms of selenium and 2 x 100 milligrams of Coenzyme Q10 daily for at least 18 months as compared with the metabolic profiles of elderly men who took matching placebos [Alehagen 2019].

Drawing on data from a sub-analysis of the KiSel-10 Study, Professor Urban Alehagen reported that the major differences were seen primarily in the following biological pathways [Alehagen 2019]:

  • pentose phosphate pathway (the pathway for the generation of nicotinamide adenine dinucleotide phosphate, which is a substance that reduces ubiquinone Coenzyme Q10)
  • mevalonate pathway (the pathway for the synthesis of cholesterol, Coenzyme Q10, and dolichol)
  • beta-oxidation pathway (the pathway for the breaking down of fatty acid molecules to produce energy and to produce acetyl-CoA, FADH2 and NADH, which are needed for the citric acid cycle [Krebs cycle]

There were other significant metabolic changes associated with the selenium and Coenzyme Q10 supplementation of senior citizens as well [Alehagen 2019].

Changes in Metabolic Profile After Supplementation with Selenium and Coenzyme Q10

In this study, Professor Alehagen and his team of researchers analyzed the metabolic patterns of 95 metabolites in the plasma of elderly men. read more

Posted on

Normal Serum Selenium Levels

Dr. Margaret P. Rayman, Professor of Nutritional Science, University of Surrey at Guildford, said in 2002: ” Se deficiency is defined by Baum et al (1997)  as  a  plasma  level  ≤ 85μg/liter,  a  level  not  attained  in many northern European countries.”

Selenium is an important trace element that is needed for the proper functioning of our cells.  It is needed in very small amounts, but it might be a good idea to have a blood test done to check the serum selenium level.

The Mayo Clinic Laboratories state that the normal concentration in adult human blood serum is 70 to 150 micrograms per liter (the same as 70 to 150 nanograms per milliliter). According to the Mayo Clinic, the US population mean value is 98 micrograms per liter [Mayo Clinic].

Variations in Serum Selenium Levels

Diet, geographic location, demographic factors, and environmental factors all influence serum selenium levels.

The following factors are independent predictors of higher selenium status in the United States [Park]: read more

Posted on

Selenium Supplementation: No Adverse Effect on Insulin Resistance

Researchers at the Arizona Cancer Center report study results that do not support any significant adverse effect of daily supplementation with 200 micrograms/day of selenized yeast on beta-cell function or insulin sensitivity. High-selenium yeast preparations contain more selenium species with more biological functions than the 100% selenomethionine preparations do.

Researchers at the University of Arizona Cancer Center in Tucson have reported interesting findings with respect to selenium supplementation [Jacobs 2019]:

  • Supplementation with 200 micrograms/day of a selenized yeast preparation for 2.9 years had no effect on insulin sensitivity or beta-cell function as compared with the placebo group.
  • Further stratification of the data by sex and age showed no effect modification in response to the selenium supplementation.

The Take-Home Message from this Selenium Research

  • The Arizona Cancer Center research does not support the idea of a major role for selenium in insulin sensitivity or beta-cell function.
  • The University of Arizona researchers write that their results provide key information for clinicians to convey to patients in the USA about the use of selenized yeast dietary supplements.

The Selenium Supplementation Research Design

The researchers analyzed the data from a subset of 400 individuals who were participating in the Selenium Trial, a randomized, double-blind, placebo-controlled trial of the effect of selenium supplementation at 200 micrograms per day on colorectal adenomatous polyps [Jacobs 2019].

The data included the fasting plasma glucose and insulin measured both before randomization and within 6 months of completing the intervention.

The researchers compared changes in the homeostasis model assessment-beta cell function (HOMA2-%beta) and insulin sensitivity (HOMA2-%S) between the active selenium treatment group and the placebo control group. read more