What is Selenium?

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Selenium is an essential mineral that plays a vital role in the proper functioning of your body. Find out what selenium is and its potential benefits.

There are many minerals which are essential to the proper workings of your body and all of its processes, one of which being selenium. This clever mineral plays a role in proper thyroid hormone metabolism, DNA synthesis, whilst also protecting the body from oxidative damage and infection.

In this article we look into what selenium is and the many benefits that have been linked to the mineral.

What is selenium?

SeleniumSelenium is an essential mineral that naturally occurs in soil and water. Interestingly, the amount of selenium in food depends on how much is found in the soil and water in which it came from and it’s found in the most concentrated doses in Brazil nuts, seafood and meats, but sometimes it’s also added to foods or taken in tablet form as a supplement.

Selenium is only needed in small amounts as the body stores it in tissue, mainly in the skeletal muscles.

Recommended daily intake for selenium

The current recommended daily intake for most adults is 55mcg, 60mcg for pregnant women and 70mcg for those that are lactating.

6 top selenium benefits

Research is currently being carried out on the effectiveness of using selenium to treat certain health conditions, but so far studies have suggested it may have the following benefits:

1. It’s an antioxidant

One of the biggest benefits to selenium is that it’s an antioxidant and can help to prevent damage to healthy cells caused by oxidative stress due to excess free radicals as a result of smoking, alcohol consumption or stress. Oxidative stress in particular has been connected to certain conditions such as heart disease and Alzheimer’s.

2. May play a part in cancer prevention

Due to the fact it’s an antioxidant, can help to prevent DNA damage and boost your immune system, one of the things selenium may be good for is the prevention of colorectal, prostate, lung, bladder, oesophageal and gastric cancers. One particular study compared the risks of cancer on those with a lower and higher selenium intake and interestingly, the higher category experienced a 31% lower cancer risk, 45% lower cancer mortality risk, 33% lower risk of bladder cancer and 22% lower risk of prostate cancer.

Further research also suggests that selenium supplements may help to reduce side effects for those undergoing radiation therapy.

3. Could protect against heart disease

Lower selenium levels have been linked to an increased risk of heart disease, so taking more of the mineral may help to protect against it. On an analysis of 25 studies, a 50% increase in selenium levels demonstrated a 24% reduction in the risk of heart disease.

On top of this, one of the selenium benefits is that it might help to lower inflammation in your body, which is one of the biggest risk factors for heart disease. Additionally, it’s an antioxidant and oxidative stress and inflammation have been linked to atherosclerosis, a build-up of plaque in the arteries which can lead to strokes, heart attacks and heart disease.

4. It may slow cognitive decline

Woman holding Brazil nutsAs concentrations of selenium decline with age, it may be that this is linked to the deterioration of brain function due to the fact it’s an antioxidant. There’s even been studies carried out that demonstrate that a lower selenium level in the blood could cause a higher risk of cognitive decline over time.

Interestingly, another small study showed that eating just one selenium-rich Brazil nut per day improved the speech and mental functions of patients with mild cognitive impairment. However, more research is necessary in this field to determine the benefits of selenium on helping to prevent or treat cognitive decline.

5. It ensures the proper functioning of thyroid glands

Thyroid tissue contains the highest amount of selenium compared to any other organ in the body. Not only can selenium help to protect the thyroid against oxidative damage, but it also has an essential role in the production of thyroid hormones which are essential for regulating your body’s metabolic rate.

Woman checking thyroid glandDeficiency in selenium has even been linked to certain thyroid conditions such as Hashimoto’s thyroiditis which is a type of hypothyroidism where the immune system attacks the thyroid gland. One study in particular analysed the effects of taking a daily selenium supplement for 3 months on individuals with Hashimoto’s disease and it was shown that it lowered thyroid antibodies and an improvement to mood and well-being was seen too.

6. It can enhance the immune system

One of the things selenium is good for is enhancement of the immune system as it can lower oxidative stress and reduce inflammation. Research demonstrates that increased levels of selenium in the blood results in a better immune response and a deficiency in selenium can reduce immune cell function and cause a slower immune response.

Another study was carried out on HIV and selenium and it was concluded that a deficiency actually increased the risk of death and progression of the disease, whereas those taking supplements saw less hospitalisations and a general improvement to symptoms.

Now you know what selenium is and the potential benefits! However, it’s important to remember that research is currently being carried out in this field and if you have any health concerns, always consult your doctor.

Want to find out more about essential minerals and why we need them? Read our guide, next.


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