Best selenium supplement
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Best Selenium Supplement: A Comprehensive Review
Introduction to Selenium Supplements
Selenium is an essential trace element crucial for various biological functions, including antioxidant defense, thyroid hormone metabolism, and immune response. It is incorporated into selenoproteins, which play significant roles in protecting against oxidative stress and supporting overall health3 7. However, the optimal form and dosage of selenium supplementation remain subjects of ongoing research and debate.
Selenium and Cardiovascular Health
Cardiovascular Disease Prevention
Selenium's role in cardiovascular health has been extensively studied, with mixed results. A comprehensive review of randomized controlled trials (RCTs) found no significant effect of selenium supplementation on reducing cardiovascular disease (CVD) events or mortality. The study also noted a potential, though not statistically significant, increased risk of type 2 diabetes with high selenium exposure1. This suggests that while selenium is essential, its supplementation may not provide additional cardiovascular benefits and could pose risks if not carefully managed.
Selenium and Thyroid Health
Hashimoto's Thyroiditis
Selenium supplementation has shown promise in managing Hashimoto's thyroiditis (HT), an autoimmune thyroid disorder. Meta-analyses indicate that selenium can significantly reduce thyroid peroxidase autoantibodies (TPOab) levels and improve mood and general well-being in patients with HT2 6. However, the impact on thyroid function and morphology remains inconclusive, and further research is needed to establish routine supplementation guidelines.
Graves' Disease
In Graves' disease, another thyroid disorder, selenium supplementation may facilitate faster remission of hyperthyroidism and improve quality of life, particularly in patients with mild thyroid eye disease4. Despite these potential benefits, selenium supplementation is generally recommended only for specific thyroid conditions, and its use should be guided by clinical evaluation.
Selenium and Cancer Prevention
Cancer Risk and Selenium
The relationship between selenium and cancer prevention is complex. Observational studies have suggested an inverse association between selenium levels and the risk of certain cancers, such as prostate, lung, and colorectal cancers7 8. However, RCTs have not consistently supported these findings, and some studies have raised concerns about the potential for increased risks of type 2 diabetes and other adverse effects with selenium supplementation8 9. Therefore, while selenium is crucial for health, its supplementation for cancer prevention is not currently recommended.
Forms of Selenium Supplements
Organic vs. Inorganic Selenium
Selenium supplements are available in both organic (e.g., selenomethionine, selenocysteine) and inorganic (e.g., selenite, selenate) forms. Organic selenium is generally considered safer and more bioavailable than inorganic forms3 10. Foods naturally rich in selenium, such as meat, seafood, and grains, are recommended for those in selenium-deficient areas, as they provide a balanced and safe source of this essential nutrient3.
Conclusion
Selenium is a vital nutrient with significant roles in various physiological processes. While selenium supplementation can be beneficial in specific conditions like Hashimoto's thyroiditis and possibly Graves' disease, its use for cardiovascular disease prevention and cancer risk reduction remains unsupported by current evidence. Organic forms of selenium are preferred due to their higher bioavailability and safety profile. As with any supplement, it is crucial to approach selenium supplementation with caution and under medical guidance to avoid potential adverse effects.
Sources and full results
Most relevant research papers on this topic
Selenium supplementation for the primary prevention of cardiovascular disease.
Selenium supplementation does not significantly reduce cardiovascular disease risk, but may slightly increase the risk of type 2 diabetes.
Meta-Analysis
Very Rigorous Journal
Highly CitedSelenium supplementation in the treatment of Hashimoto's thyroiditis: a systematic review and a meta-analysis.
Selenium supplementation significantly decreases thyroid peroxidase autoantibodies and improves mood and well-being in Hashimoto's thyroiditis patients, but further evidence is needed for routine recommendation.
Meta-AnalysisHighly CitedSelenium transformation and selenium-rich foods
Organic selenium is safer than inorganic selenium and is recommended for those in selenium-deficient areas, while selenium-rich foods are the safest and best recommendation for those in selenium-deficient areas.
Highly CitedSelenium in thyroid disorders — essential knowledge for clinicians
Selenium supplementation may reduce thyroid autoantibody levels in chronic autoimmune thyroiditis, but its effectiveness in Graves disease remains unclear.
Highly CitedDevelopmental selenium exposure and health risk in daily foodstuffs: A systematic review and meta-analysis.
High selenium levels in meat, eggs, poultry, and seafood are essential for human health, but supplementation for prevention of cardiovascular, hepatopathies, or cancer diseases is ambiguous and may increase toxicity risk.
Meta-AnalysisSelenium Supplementation Significantly Reduces Thyroid Autoantibody Levels in Patients with Chronic Autoimmune Thyroiditis: A Systematic Review and Meta-Analysis.
Selenium supplementation significantly reduces thyroid autoantibody levels in patients with chronic autoimmune thyroiditis after 3, 6, and 12 months of treatment.
Meta-Analysis
Rigorous JournalHighly CitedThe Role of Selenium in Pathologies: An Updated Review
Adequate selenium intake and supplementation may improve prognosis and reduce the risk of developing various diseases, but excessive levels may have adverse effects.
Literature ReviewRigorous JournalHighly CitedSelenium for preventing cancer.
Higher selenium exposure is associated with lower cancer incidence and mortality, but no clear evidence exists for its effectiveness in cancer prevention through supplementation.
Systematic ReviewVery Rigorous JournalHighly CitedSelenium for preventing cancer
Higher selenium exposure may reduce cancer risk, but there is no convincing evidence that selenium supplements can prevent cancer in men, women, or children.
Meta-AnalysisVery Rigorous JournalHighly CitedSelenium–Fascinating Microelement, Properties and Sources in Food
Selenium is an essential micronutrient essential for proper functioning of all organisms, protecting against oxidative stress and promoting human health.
Highly Cited