Dementia Archives - Seleniumfacts.com

April 15, 2022April 20, 2022

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

November 22, 2018June 11, 2026

Circulatory selenium concentrations and Alzheimer’s disease

Brain tissue produces many free radicals (reactive oxygen species). The oxidative stress caused by an imbalance between potentially harmful free radicals and antioxidants to neutralize them is associated with ageing and with the onset of Alzheimer’s disease. Reduced levels of the selenium-dependent antioxidant enzyme glutathione peroxidase correlate strongly with cognitive decline and the risk of Alzheimer’s disease.

Blood selenium concentrations are significantly lower in patients with Alzheimer’s disease compared to healthy controls. This reduction in selenium concentration is directly associated with the observed reduced levels of the important antioxidant selenoprotein, glutathione peroxidase, in Alzheimer’s disease patients.

These are the conclusions of the authors of a 2017 meta-analysis of 12 case-control studies of selenium concentrations in Alzheimer’s disease patients and healthy controls. The 12 case-control studies comprised 594 Alzheimer’s disease patients and 472 healthy controls [Reddy].

Selenium and Alzheimer’s disease meta-analysis

The results of the systematic review and meta-analysis revealed the following associations:

Significantly decreased selenium levels were seen in the blood circulation of Alzheimer’s disease patients as compared to healthy controls.
Decreased selenium levels were also seen in the red blood cells and cerebrospinal fluid of Alzheimer’s patients as compared to healthy controls. However, the difference in selenium concentrations did not reach the level of statistical significance.
Age matching between the Alzheimer’s disease patients and healthy controls showed decreased selenium levels regardless of the age of the patients. This is interesting because advanced age is considered a risk factor for Alzheimer’s disease.
Controlling for socio-economic, geographical, and environmental differences also showed the decreased selenium levels in Alzheimer’s disease patients compared to the healthy controls.
A direct association was seen between decreased selenium levels and glutathione peroxidase levels in Alzheimer’s disease patients.

What is glutathione peroxidase, and why is it important?

The glutathione peroxidases (abbreviated GPx) are a family of antioxidant enzymes (selenoproteins) that reduce and thus neutralize potentially harmful radicals like hydrogen peroxide and lipid hydroperoxides. In so doing, the GPx enzymes lessen the extent of oxidative stress damage. read more

November 3, 2017June 12, 2026

Selenium and Alzheimer’s disease and cognitive decline

Pictured: A healthy brain and a brain suffering from severe Alzheimer’s disease. The question: what is the role of the selenium-dependent antioxidant seleno-enzymes in the prevention of Alzheimer’s disease? Professors Aaseth and Alehagen offer an explanation.

There is no reliable method to prevent the development and progression of Alzheimer’s. There is no known cure for Alzheimer’s. The approaches that we have tried over the past 20-25 years have not prevented or inhibited the decline in cognitive function that is associated with Alzheimer’s.

Now, Professor Jan Aaseth (Norway) and Professor Urban Alehagen (Sweden) propose selenium supplementation as a prophylactic measure to inhibit the decline of cognitive function, especially in the selenium-poor regions of the world. They hypothesize that the optimal functioning of the selenoproteins SEPP, GPx, and TrxR is necessary to protect against the cognitive decline associated with Alzheimer’s disease. read more

Milestones in early selenium research

1817 Swedish chemist Jöns Jakob Berzelius discovers selenium

1957 Biochemist Klaus Schwarz shows that selenium in microscopic amounts has a vital importance for mammalian health

1969 Professor J.T. Rotruck discovers that selenium has a biochemical role as a component of the antioxidant enzyme glutathione peroxidase

1969 Professors R.J. Shamberger and D.V. Frost report a possible protective effect of selenium against cancer in humans

1973 Professor J.T. Rotruck identifies the enzyme glutathione peroxidase as a selenium-dependent protein

1977 Professor G.N. Schrauzer publishes cancer mortality correlation studies showing an inverse correlation between dietary intakes of selenium and cancer mortality in 27 countries

1988 Professor G.Q Yang summarizes the lessons learned about the selenium-related endemic diseases Keshan disease and Kashin-Beck disease and about the importance of adequate daily selenium intakes

1989 Professor G.G. Duthie publishes evidence for a role of selenium in the prevention of cardiovascular disease

1993 Researcher W.J. Blot publishes the results of the Nutrition Intervention Trials in Linxian, China, showing that supplementation with a combination of selenium and other antioxidants reduces the risk of cancer

1994 Professor G.N. Schrauzer publishes evidence that selenium is important in the maintenance and therapy of HIV-infected patients

1996 Professor Larry Clark publishes the results of a randomized controlled trial – the Nutritional Prevention of Cancer study -- that shows selenium's cancer-protective effects on colon cancer, lung cancer, and prostate cancer

1997 Professor G.F. Combs summarizes the evidence for the protective effects of selenium against cancer

1999 Professor J.E. Oldfield publishes his Selenium World Atlas, mapping areas of selenium deficiency around the world

2000 Researcher O.A. Levander publishes evidence showing an anti-viral effect of selenium

2002 Researcher R. Gärtner shows that supplementation with selenium reduces inflammation in patients with autoimmune thyroiditis

2002 Researcher Margaret Rayman presents the arguments for increasing selenium intakes to realize selenium’s antioxidant and anti-viral and anti-inflammatory effects as well as selenium’s enhancement of immune function and reproductive success.