Before clicking on this article, you may not be aware of the advantageous health benefits of having a diet full of selenium-rich foods.

This article highlights everything you need to know about selenium, selenium deficiency and more.

What Is Selenium?

Selenium is known as an essential mineral which means that this powerful antioxidant must be obtained through our daily diet or as a supplement to keep us in fine fettle. It is important to stress that a supplement should only be a small amount as our body can only accept and use a little at a time.

Selenium is a water-soluble mineral which is absorbed very quickly and any we don’t use is usually excreted within 24 hours. Therefore, it is highly recommended to take a little and take it regularly.

Why Is It So Important?

Selenium performs a very important role in major processes within our body, most notably in conjunction with our metabolism and the working of our thyroid gland.

The effects of selenium deficiency can show as one or more of the following:

  • Prolonged fatigue
  • A lack of mental clarity, colloquially known as ‘brain fog’
  • Hair loss
  • Infertility in both men and women
  • Muscle weakness
  • Susceptibility to illnesses due to a weakened immune system

These are typical symptoms that we would notice.  However, as selenium may reduce the risk of certain cancers and heart disease, there are serious health issues which may remain hidden for a long time and can be traced to a deficiency in the levels of selenium within our body.

What Are The Main Health Benefits of Selenium?

1. Antioxidant

An antioxidant is a substance which prevents or slows damage to our cells caused by unstable molecules, known as ‘free radicals’ which our body produces naturally as a reaction to various pressures.  

They are important in helping our bodies be protected from diseases.  However, an excess of free radicals (associated with smoking, alcohol consumption and stress) leads to oxidative stress. Oxidative stress is an imbalance between free radicals and antioxidants within our bodies. The free radicals react very easily with other molecules causing large chain chemical reactions.  These reactions are known as ‘oxidation’. Some of these are vital to our health, but others can be very harmful.

Antioxidants help calm the free radical by giving it an electron whilst allowing it to stabilise.  This helps our body’s defence against chronic illnesses such as cancer and heart disease.

2. Fights Cancer

Selenium may reduce the risk of certain cancers.  It reduces damage to our DNA, boosting our immune system and destroying cancerous cells.  In a review of 69 studies which looked at selenium obtained through diet rather than supplements, a higher level of selenium in the blood of over 350,000 people was associated with reducing the risk of cancer to the colon, lungs, prostate, and breasts.

An additional study involving women with cervical cancer or endometrial cancer found that oral supplements reduced diarrhoea caused by the radiation treatment they were undergoing.

3. Boosts Immune System

Our immune system works to keep our body healthy as it detects and fights potential threats, such as viruses, bacteria and parasites. 

By lowering the levels of oxidative stress, selenium reduces inflammation and enhances immunity in our bodies.  Low levels of selenium in our body harm the function of immune cells, causing a slower immune response.

Additional studies have suggested that higher levels of selenium in people suffering from HIV, Hepatitis C, influenza and tuberculosis can help boost their immune system.

4. Prevents Mental Decline

Once again, oxidative stress is believed to be a contributing factor behind the onset of neurological diseases and subsequent deterioration in people suffering from Alzheimer’s, Parkinson’s and multiple sclerosis (MS).  

A diet rich in high selenium level foods, such as the Mediterranean diet, has been associated with a notably lower risk of developing such conditions.  In addition, studies have found that the antioxidants found in specific foods and supplements have improved memory and verbal fluency in people with cognitive impairment.

5. Helps Protect Against and Fight Heart Disease

Oxidative stress and inflammation can lead to a condition known as ‘atherosclerosis’, which is a building up of plaque in our arteries.  This leads to very serious health problems such as heart attacks, strokes and other kinds of heart disease.

The results of 25 observational studies revealed that an increase of 50% in the level of selenium within people’s blood gave a 24% reduction in the risk of developing heart disease.  

A separate review of 16 different studies involving over 433,000 people suffering from heart disease, showed that taking a selenium supplement every day decreased the levels of inflammation shown in the inflammatory marker C-reactive Protein.

6. Helps Thyroid Health

It is vitally important to have a healthy thyroid gland as this is responsible for the regulation of our metabolism and governs our growth and development.  Our thyroid tissue contains the highest amount of selenium, more than any other organ in our body.

Low levels of selenium found in an observational study of over 6,000 people showed that they were at greater risk of autoimmune thyroiditis and hypothyroidism, in which the immune system turns on the body by attacking the thyroid gland.

7. Gives Relief from Asthma Symptoms

Asthma affects our airways which carry air both to and from our lungs by becoming inflamed and more narrow.  This causes wheeziness, shortness of breath, coughing and tightness in the chest.  Asthma has also been associated with oxidative stress.  

As selenium can reduce inflammation, some studies have found that it can have a beneficial effect on the person suffering from asthma when reducing their symptoms.

It is believed that people who suffer from asthma who have higher levels of selenium in their blood found their lungs functioned better than those with lower selenium levels.

It’s early days in the research relating to selenium and asthma before the full benefits can be confirmed.

Food Sources of Selenium

Foods which have high levels of selenium include seafood, nuts and mushrooms.  However, the levels of selenium in foods can vary quite distinctly, depending upon the conditions in their environment. 

Foods which are derived from plants will see their levels of selenium vary due to the content of the soil in which they are grown.  To illustrate this variety in levels, a study focusing on selenium levels in Brazil nuts found that a nut from one region provided 288% of the recommended daily intake (RDA), whereas another nut from a different region yielded only 11% of the RDA.  That is a quite remarkable difference!

Due to this variety in levels of selenium, it is recommended to consume a range of selenium-rich foods including:

  • Oysters
  • Brazil nuts
  • Halibut
  • Yellowfin tuna
  • Eggs
  • Sardines
  • Sunflower seeds
  • Chicken breast
  • Shiitake mushrooms

Word of Warning

To bolster your selenium levels, it could be helpful to take a supplement alongside a healthy diet, as the body will excrete what it doesn’t need or use. Hence, there is little risk of ‘overdoing’ selenium supplementation. That said, you don’t want to be flushing excess selenium down the loo either!

Given its immune–boosting and energy–giving properties, we include selenium in our Immunity IV Booster Drip which ensures it goes into the bloodstream in a form readily absorbed by the body.  It could be just the tonic your body needs, after which an oral supplement or change in diet can keep you on track.