Selenium Benefits: Everything You Need to Know

Selenium is one of the lesser-known essential trace minerals and there’s no shortage of reasons to make sure our intake of selenium is optimized. As an essential micronutrient, selenium cannot be produced by the body and, as a result, it needs to be obtained through selenium-rich foods or supplementation. (21) From supporting our immune systems to protecting our bodies from degenerative disease, there are so many reasons to make room on our plates for foods high in selenium. (5)

What is selenium and how much do you need?

As an essential micromineral, selenium is needed by the body in small amounts. According to established Recommended Daily Allowances (RDAs), children need 20 mcg to 40 mcg of selenium per day and adults require 55 mcg per day to maintain optimal health. While recommendations don’t vary based on sex, nutrient needs increase to 60 mcg to 70 mcg per day for women who are pregnant or breast feeding. (9)

Top 5 selenium benefits

Interested in learning more about this underrated mineral? Read on to discover five important reasons to incorporate selenium-rich foods into your diet.

Provides antioxidant effects

In order to understand the role selenium plays as an antioxidant, we have to understand the role of free radicals. Free radicals are byproducts of normal cell metabolism and can also come from environmental stressors such as smoking, medications, and pollution. While free radicals are a very normal part of our biology, an abundance of free radical activity can contribute to oxidative stress, which is linked to many of the chronic, degenerative diseases, such as cancer, cardiovascular disease and autoimmune disorders. (1)(7) In order to counteract these free radicals, our body must make antioxidants or acquire them from the foods we eat in order to neutralize free radicals and prevent oxidative stress. This is where selenium comes in. Considered an antioxidant, optimal selenium intake can help reduce and protect against oxidative stress. (3)(21)

Strengthens the immune system

Selenium has been shown to be beneficial in enhancing the immune response and reducing inflammation, protecting the body against specific pathogens, such as viruses. Low serum levels of selenium have been shown to slow the response of immune cells. (6) Furthermore, dietary supplementation has been shown to be beneficial in the prevention and recovery of infections due to the influenza A virus. (25) Not only can this essential mineral protect against specific viruses, it has also been shown to slow disease progression in immune-compromised individuals with human immunodeficiency virus (HIV). Interestingly, low selenium serum levels have also been reported in patients who are HIV positive. (26)

Supports thyroid function

Did you know that the thyroid gland contains the highest amount of the selenium compared to any other organ in the body? Selenium is essential to thyroid function, as it is needed for the metabolism of thyroid hormones. Therefore, it comes as no surprise that selenium supplementation has been shown to be beneficial for individuals with thyroid disease. (28) For example, in patients with Hashimoto’s thyroiditis, supplementation of selenium has been shown to boost mood and overall quality of life. (27) It has also been demonstrated that low selenium serum levels can result in an increased risk for the development of thyroid disease. (29)

Supports cancer prevention and therapy

Studies have shown that selenium’s antioxidant and anti-inflammatory effects may reduce the risk of developing certain types of cancers, such as breast, lung, prostate, and skin cancer. (4) Several studies have suggested that selenium supplementation can increase quality of life and decrease side effects in cancer patients undergoing radiotherapy treatment. (20) Another study specifically looked at selenium’s impact on patients undergoing gynecological radiation therapy, highlighting the mineral’s ability to reduce side effects like radiation-induced diarrhea. (8)

Reduces cognitive decline

The number of people who suffer from Alzheimer’s disease is staggering – five million Americans are living with the degenerative disease, and sadly, the numbers are steadily increasing. (2) Selenium, in combination with other lifestyle factors, may play a role in reducing oxidative stress that is believed to play an important role in the progression of Alzheimer’s disease. (23) Furthermore, brazil nuts, which contain one of the highest dietary sources of selenium, have been studied for their positive effects on cognitive performance. In adults with pre-existing cognitive impairment, brazil nuts have been shown to increase antioxidant activity, therefore reducing oxidative stress linked to cognitive decline. (22)

Foods high in selenium

Brazil nuts are one of the highest and most well-known dietary sources of selenium. (24) Along with Brazil nuts, some of the best sources of selenium are outlined below.

Should you supplement with selenium?

If you’re having a hard time obtaining selenium from dietary sources alone or you require it in greater amounts, consult with your integrative health care practitioner about adding a selenium supplement to your protocol in order to reach your RDA.

The bottom line

There are many reasons to ensure optimal selenium intake, from reducing oxidative stress and supporting immune and thyroid function to preventing cognitive decline and cancer Luckily, there is an abundance of selenium-rich whole foods from which to choose from in order to meet recommended amounts. In unique cases when supplementation is needed, it’s best to consult with your integrative healthcare practitioner to see if selenium supplementation is right for you.