7 Advantages and Disadvantages of Taking Selenium
Selenium is an essential trace mineral that plays a crucial role in various physiological functions, including antioxidant defense, thyroid hormone metabolism, and immune response. Although only a small amount of selenium is required for health, both selenium deficiency and excessive intake can have significant health implications. Understanding the benefits and potential drawbacks of taking selenium supplements or increasing selenium intake through diet is important for maintaining optimal health.
Written by
- Redaction Team
- Body, Healing Foods, Personal Development
Table of Contents
Advantages of Taking Selenium
Selenium Helps Boost Antioxidant Activity
Selenium is an essential component of several antioxidant enzymes, including glutathione peroxidase, which helps neutralize harmful free radicals in the body. These enzymes protect cells from oxidative stress, which is linked to chronic diseases such as heart disease and cancer. Research has shown that selenium supplementation improves antioxidant activity, especially in individuals with low selenium levels.
Daily selenium intake, even in small amounts, can significantly enhance the activity of selenium-containing enzymes. This contributes to reducing inflammation and cellular damage.
Selenium May Support Immune Function
One of the important benefits of selenium is its role in supporting a healthy immune system. Selenium helps stimulate the production and activity of white blood cells, which are essential for fighting infections. Selenium deficiency can cause weakened immune responses and may increase susceptibility to illness.
Selenium supplementation in adult populations, particularly those with compromised immunity, has been associated with improved immune function. Selenium may also enhance the body’s response to viral infections and has shown promise in some preliminary research related to viral diseases.
Selenium and Thyroid Health
Selenium is a key player in thyroid hormone metabolism. It is involved in the conversion of thyroxine (T4) to the more active triiodothyronine (T3), and selenium deficiency can disrupt this process. Maintaining optimal selenium levels is important for people with thyroid disorders.
Selenium supplementation in the treatment of autoimmune thyroid diseases, such as Hashimoto’s thyroiditis, has shown beneficial effects in some studies. The effect of selenium supplementation on thyroid function is an active area of research.
Potential Protective Role Against Certain Cancers
There is evidence suggesting a possible association between selenium and prostate cancer risk reduction. Some observational studies have found that higher blood selenium levels are linked to a lower risk of several types of cancer, particularly prostate, lung, and colorectal cancers.
However, the relationship between selenium and cancer is complex and not fully understood. While selenium may be able to reduce oxidative stress and inflammation that contribute to cancer development, more research is needed to determine whether selenium supplementation directly reduces cancer risk.
Disadvantages of Taking Selenium
Risk of Selenium Toxicity from High Intake
Although selenium is an essential mineral, taking too much selenium can cause toxicity. Acute selenium toxicity, though rare, can occur from high-dose intravenous selenium or excessive oral supplementation. Signs of selenium toxicity include nausea, hair loss, fatigue, and neurological damage.
The recommended upper limit is 400 mcg per day for adults. Consistently taking high levels of selenium above this limit could lead to selenium toxicity. It is crucial to monitor the amount of selenium consumed through diet and supplements.
Negative Effects of Excessive Supplementation
High selenium exposure through supplements, especially when selenium status is already adequate, may have unintended consequences. Some studies have reported that high selenium levels may be linked to an increased risk of type 2 diabetes, although findings remain inconclusive.
The effect of selenium supplementation on glycemic control varies among individuals, and excessive intake may have adverse metabolic effects. Therefore, it’s important to avoid taking selenium supplements unless there is a clear deficiency or medical need.
Inconsistent Evidence for Certain Health Claims
While selenium has many health benefits, some claims about its effects remain uncertain or exaggerated. For example, the impact of selenium supplementation on cancer prevention and cardiovascular disease risk has produced mixed results.
Some clinical trials have not shown significant improvements in health outcomes from selenium supplementation in healthy individuals. Overreliance on supplements, instead of obtaining selenium from natural sources, may not offer the same protective benefits.
Sources of Selenium in the Diet
Best Sources of Selenium from Food
Dietary selenium can be obtained from a variety of foods. Selenium in food is typically found in two forms: organic or inorganic selenium. Organic forms, such as selenomethionine, are more bioavailable.
Animal products like eggs, tuna, chicken, and beef liver are rich in selenium. Brazil nuts are among the best sources of selenium, containing very high levels in even a single nut. Plant-based foods like sunflower seeds and whole grains also contain selenium, although the selenium content depends on soil concentration.
Selenium in food generally provides a safer and more balanced intake compared to supplements. Dietary selenium supplementation is encouraged over long-term use of high-dose supplements.
Selenium Intake Recommendations
How Much Selenium is Safe?
The recommended dietary allowance (RDA) for selenium varies by age and sex, but for adults, it is typically around 55 mcg per day. Selenium supplements may be used to meet this target when dietary intake is insufficient, but care must be taken not to exceed the upper safe limit of 400 mcg per day.
Maintaining proper selenium status requires balancing intake with individual health needs. Regular testing of blood selenium levels or serum selenium levels may be advised in cases of suspected deficiency or chronic illness.
Signs of Selenium Deficiency
What Happens with Low Selenium Levels?
Selenium deficiency can cause various symptoms, including fatigue, cognitive decline, weakened immunity, and infertility. Secondary to selenium deficiency, individuals may also develop heart conditions like Keshan disease, especially in selenium-deficient regions such as parts of China.
Low selenium levels can be the result of poor dietary intake, malabsorption syndromes, or living in regions with selenium-poor soil. In such cases, taking selenium under medical supervision can help restore healthy levels of the mineral and prevent long-term complications.
Conclusion
Selenium is a mineral that helps maintain overall health through its roles in antioxidant defense, immune function, and thyroid hormone metabolism. Although selenium supplements may offer health benefits, especially in cases of selenium deficiency, excessive intake can lead to toxicity and health risks.
The best approach is to ensure adequate dietary selenium intake through food sources, while only using supplements when necessary. Monitoring selenium levels and understanding the balance between benefits and risks is key to optimizing your selenium status and overall well-being.
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