Selenium – the secret of a healthier life and longevity?

Critical roles in cancer prevention, healthy thyroid, heart & mind

You might never have heard about the importance of consuming Selenium. However it is critical that you eat enough, but not too much Selenium rich food to live a longer, healthier life!

Selenium is a critical trace element and a recent study of blood donors in Australia suggested that deficiency (or borderline deficiency) could be widespread even in healthy younger people!

Several studies have shown that Selenium is very important in healthy ageing.

  • All the centenarians who have been studied have had high body levels of Selenium.
  • A recent study in China showed that the longest living people had the highest levels of Selenium.
  • The European EVA study of aging also showed a very strong statistical association between higher levels of Selenium and longevity.
  • Using slightly different criteria, numerous published medical studies show that healthy elderly people have higher levels of Selenium than those who require ongoing living support or are institutionalised.

I think it is best to obtain your nutrients from ‘natural’ food. So here is a list of the top 10 food sources of Selenium. The recommended daily amount varies between different sources but 100 to 200 micrograms each day is probably ideal for older people. This should NOT be exceeded because being a ‘trace element’ it is as dangerous to have too much as it is to have too little!

OrderMicrograms SeleniumPer 100 grams Food
11917Brazil Nuts
2354Four or more nuts other than Brazil nuts but without peanuts!
3181.5Lamb Kidney
4168Beef Kidney
5160Dried Atlantic Cod
6124.4Cooked Sardines
7100Veal Kidney
897Cooked Mullet
996Boiled Mussels
1093Canned Tuna
(data taken from the AUSNET 2011-2013 list of 53 nutrients in 5,740 foods and beverages)

It’s easy to see that Brazil nuts are by far the highest source of Selenium and about five nuts a day will give you all you need. If you ingest Selenium from other foods, eat less Brazil nuts!

Trace Elements

Our bodies’ trace elements include Selenium, Iron, Cobalt, Nickle, Chromium, Zinc, Vanadium, Copper, Manganese, Molybdenum, and Iodine, which are all engaged in major body functions.  You need some of each of these – so more about the others in a future blog.

Among the trace elements, Selenium (Se) represents a concentration of 0.2–0.3 µg/g body weight. Along with other micronutrients, such as oligo-elements, vitamins, and antioxidants, Se is a vital element for the body’s health, and its LOW or HIGH intake can lead to serious disorders!

The Science: Antiviral, Antioxidant, Anti-inflammatory Roles

Selenium is necessary for the structure and function of 25 key body enzymes. There are 12 known “selenoproteins” that are important components of the antiviral, antiproliferative, antioxidant, and anti-inflammatory defence systems.

The Science: Thyroid Function, Cancer Prevention, and Immunity Roles

Selenium is a component of three “Iodothyronines” that are critical to the normal function of the Thyroid gland. It also contributes to a further three “Thioredoxin” enzymes that play critical roles in cancer prevention. Selenium is also critical for the normal function of the Thyroid gland through one Iodothyronine deiodinase and three Iodothyronine deiodinase enzymes. It also plays another critical role in immunity via its part in the production of Actin in Macrophage cells.

If this weren’t enough, Selenium also forms part of five known Glutathione Peroxidase enzymes that play critical roles in defending our bodies against ‘oxygen radicals’.

Because of all these diverse roles, Selenium positively intervenes in preventing a wide range of diseases but especially cancer, thyroid disease and cardiovascular diseases.

Selenium and Diseases of the Ageing Brain and Nervous System

Some of the Selenium proteins are also engaged in various functions of the central nervous system. These include cognitive performance, memory, and motor coordination. For this reason, Selenium is thought to play a beneficial role in preventing several very serious neurodegenerative disorders associated with ageing including Parkinson’s and Alzheimer’s diseases!

Roles in earlier stages of Life

In earlier life, Selenoproteins play an important role in both female and male reproductive function in both males and females. Many problems of infertility and foetal development are caused by Selenium deficiencies, but this will be discussed in a separate blog.

Crush nuts if necessary!

When I spoke about Selenium in one of my recent talks, one of the audience members was concerned that some older people might have difficulty chewing nuts. Another person wisely suggested that nuts can easily be ground up and added to other foods. There are many possibilities but always remember to eat Selenium rich foods for a longer healthier life.

Much more information is given in my online courses on this website.

Published by Dr Judy

I am a PhD Geneticist and have spent many decades working in research related to reproduction and cancer. Both are affected by lifestyle, especially ageing and so I am passionate about teaching people how to change their lifestyles to optimise their health.

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