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