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 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

Selenium and Anti-Aging Effects

Maintaining adequate selenium status is an acknowledged anti-aging strategy. We need selenium to live longer and to be healthier as we age. Adequate intakes of selenium and adequate bio-synthesis of selenoproteins contribute to healthy aging and to reduced vulnerability to various disorders. Selenium and selenoproteins are important for the following biological activity [Bjorklund 2022]:

  • antioxidant protection
  • enhancement of immune system function
  • metabolic homeostasis
Crowds of people
Bjorklund et al estimate that selenium deficiency affects about one billion people in the world and may have a significant adverse effect on human health.

One characteristic of aging is oxidative stress.

Oxidative stress is defined as an imbalance between the damage caused by harmful free radicals and the protection offered by antioxidants. Inadequate selenium status can reduce the longevity and the health of senior citizens by accelerating the aging process and/or increasing vulnerability to immune system dysfunction, cardiovascular disease, and cancer [Bjorklund 2022]. read more

Impact of Selenium Status on Biological Aging

Aging. Getting up in years. Striving to live as long as possible and to be as strong and healthy as possible. At some point, good health becomes a more important concern than wealth. Optimal selenium status is important to good health [Alehagen 2021].

Professor Jan Aaseth
Professor Jan Aaseth, MD, PhD, researcher in internal medicine, endocrinology, and toxicology and specialist in selenium research.

In a review article, Professor Urban Alehagen and Professor Jan Aaseth list the following conditions associated with biological aging [Alehagen 2021]:

  • chronic mild to moderate systemic inflammation
  • detrimental DNA alterations
  • mitochondrial dysfunction
  • oxidative stress caused by harmful free radicals
  • telomere shortening

Getting old is inevitable. Biological aging necessarily involves a weakening of the immune system and increased susceptibility to diseases and environmental stresses.

Selenium deficiency associated with aging and aging-related diseases

Selenium deficiency is associated with mitochondrial dysfunction, oxidative stress, and inflammation [Alehagen 2021].

Mitochondrial injuries are an important factor in the aging of human cells.  A by-product of the mitochondrial generation of ATP energy in the cells is the production of reactive oxygen species, some of which are useful and some of which are harmful. The leakage of these harmful free radicals from the mitochondrial respiratory chain increases with age, which results in cellular oxidative damage, whenever there are not enough antioxidants to neutralize the effects of the free radicals. 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 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