Selenium: trace element with great effects

Selenium: trace element with great effects

Selenium, an often overlooked trace mineral, plays an understated yet crucial role in human health and nutrition. This vital nutrient, hidden in the food chain, holds a wealth of benefits that only become apparent upon closer scientific examination. The essential importance of selenium is undisputed, but how much is enough and how much is too much? Research into selenium has painted a detailed picture of its mechanisms of action, health benefits and potential risks of overdose. This article takes an analytical look at the essential role of selenium in our health and nutrition, highlights scientifically supported health benefits, and discusses the potential risks of selenium supplementation. Finally, recommendations and guidelines for safe selenium intake are presented based on current research results. Immerse yourself with us in the fascinating world of a trace element that has a major effect on our body and find out how you can optimize your selenium balance.

The essential role of selenium in human health and nutrition

Selenium is an essential trace element that is central to human health. It plays a key role in immune system function, prevention of oxidative stress and thyroid hormone metabolism. Selenium is known to be a component of over 25 selenoproteins, which are involved in various biological processes, including antioxidant defense and the regulation of inflammatory processes.

• Immunsystem: Selen trägt zur Stärkung des Immunsystems bei, indem es die Proliferation von T-Helferzellen fördert und die Antikörperproduktion unterstützt.
• Antioxidative Wirkung: Als Bestandteil von Glutathionperoxidasen hilft Selen, die Körperzellen vor oxidativem Stress zu schützen, der unter anderem durch freie Radikale verursacht wird.
• Schilddrüsenfunktion: Für die Synthese und den Abbau der Schilddrüsenhormone ist Selen erforderlich. Ein Selenmangel kann zu Schilddrüsenerkrankungen führen.

The recommended daily intake of selenium varies depending on age, gender and stage of life. According to the US National Research Council, a daily intake of 55 micrograms is recommended for adults. Pregnant and breastfeeding women have increased needs.

Selenium occurs naturally in a variety of foods, particularly Brazil nuts, fish, meat, eggs and some grains. The selenium concentration in plant foods depends largely on the selenium content of the soil in which the plants are grown. In regions with selenium-poor soils, there may be a lack of selenium in the diet of the population living there.

A lack of selenium can lead to a number of health problems, including heart disease, male infertility and a weakened immune system. On the other hand, excessive intake of selenium can cause toxic effects such as hair loss, nausea, irritability and, in severe cases, even organ failure. Balancing selenium intake is therefore essential for maintaining health.

Science-backed health benefits and potential risks of selenium supplementation

Selenium is an essential trace element that is central to human health. Scientific studies have shown that adequate selenium intake is associated with various health benefits. Highlighted benefits include:

• Unterstützung des Immunsystems: Selen spielt eine wichtige Rolle in der Funktion des Immunsystems. Es trägt dazu bei, die Körperabwehr zu stärken und kann vor bestimmten Infektionen schützen.
• Schutz vor oxidativem Stress: Als Bestandteil von Antioxidantien hilft Selen, Zellen vor Schäden durch freie Radikale zu schützen und reduziert damit das Risiko chronischer Krankheiten.
• Prävention von Herz-Kreislauf-Erkrankungen: Studien legen nahe, dass eine ausreichende Selenzufuhr mit einem reduzierten Risiko für Herzerkrankungen verbunden ist, möglicherweise durch Verringerung von Entzündungen und Verbesserung der antioxidativen Kapazität im Körper.

At the same time, there are potential risks associated with excessive selenium intake, particularly through supplementation. Excessive selenium intake can lead to various health problems, including:

• Selenose: Eine Erkrankung, die durch Symptome wie gastrointestinale Beschwerden, Haar- und Nagelverlust, Hautausschlag und in schweren Fällen neurologische Schäden charakterisiert ist.
• Interaktion mit Medikamenten: Selen kann mit bestimmten Medikamenten interagieren und deren Wirksamkeit beeinflussen oder unerwünschte Nebenwirkungen hervorrufen.
• Risiko für Diabetes: Einige Studien verweisen auf einen Zusammenhang zwischen hohen Selenlevels im Körper und einem erhöhten Risiko für die Entwicklung von Typ-2-Diabetes.

It is important that selenium intake remains within recommended limits. The exact requirements may vary depending on age, gender and health status. The German Nutrition Society (DGE) recommends a daily selenium intake of 60-70 micrograms for adults.

In conclusion, adequate selenium intake can provide significant health benefits, but excessive supplementation carries potential risks. Individual needs and health circumstances should always be considered when deciding whether to supplement.

Recommendations and guidelines for safe selenium intake: An analysis based on current research

The optimal selenium intake varies depending on age, gender and health condition. The general daily reference values ​​proposed by scientific bodies are based on the amount of selenium necessary to achieve maximum activity of glutathione peroxidase in blood plasma. This enzyme plays a key role in protecting cells from oxidative stress.

• Erwachsene sollten eine tägliche Selenaufnahme von etwa 55 Mikrogramm anstreben.
• Für schwangere und stillende Frauen wird eine erhöhte Aufnahme von 60 bzw. 70 Mikrogramm empfohlen, um den erhöhten Bedarf zu decken.

The upper intake limit for selenium, which should not be exceeded, is 400 micrograms per day for adults. Chronic intake of selenium in amounts exceeding this limit can lead to health problems such as selenosis, a condition characterized by symptoms such as hair loss, nail changes, nausea and nerve damage.

It is important to note that selenium is primarily obtained through diet, through consumption of fish, meat, eggs, and selenium-rich nuts such as Brazil nuts. However, the selenium content in foods can vary greatly depending on the selenium concentration in the soil in which the food was grown. In some areas where soils are poor in selenium, dietary intake may be inadequate.

In such cases or with certain diets, such as a strict vegan diet, supplementation may be necessary, but should only be done after consultation with a healthcare provider. Self-medication with high doses of selenium without professional supervision should be avoided due to the risks of toxicity and undesirable interactions.

Adhering to recommended intake levels and monitoring selenium intake through regular blood tests are effective strategies to assess individual selenium status and ensure balanced supply while minimizing the risks of over- or under-supply.

In conclusion, although selenium is a micronutrient, its impact on human health is anything but minor. The essential importance of this trace element, from supporting the immune system to preventing cardiovascular diseases, underlines the need for a balanced diet and shows how adequate selenium intake can support vital body functions. At the same time, scientific discussion of the potential risks of selenium supplementation highlights that excessive intake can be detrimental to health, underpinning the importance of well-thought-out supplementation based on sound research. Future research is essential to further decipher the exact mechanisms of selenium in the body and to refine targeted recommendations for different populations. Until then, existing guidelines for safe selenium intake should serve as a valuable resource to maximize the health benefits of selenium and minimize potential risks.

Sources and further literature

References

• National Institutes of Health (NIH). „Selenium: Fact Sheet for Health Professionals.“ Online verfügbar auf der Website der NIH.
• Bundeszentrum für Ernährung (BZfE). „Selen.“ Veröffentlicht auf der BZfE-Website.
• Deutsche Gesellschaft für Ernährung e. V. (DGE). „Referenzwerte für die Nährstoffzufuhr: Selen.“ Veröffentlicht in der 2. Auflage der DGE-Referenzwerte für die Nährstoffzufuhr.

Studies

• Rosenfeld, I., & Beath, O. A. „Selenium: Geobotany, Biochemistry, Toxicity, and Nutrition.“ Academic Press, 1964. Diese historisch bedeutende Studie bietet grundlegende Einsichten in die Biochemie des Selens.
• Rayman, M. P. „The importance of selenium to human health.“ In The Lancet, Volume 356, Issue 9225, 2000. Die Studie dokumentiert die zentrale Rolle von Selen für die menschliche Gesundheit.
• Zhang, J. et al. „Association between regional selenium status and reported outcome of COVID-19 cases in China.“ In The American Journal of Clinical Nutrition, Volume 111, Issue 6, 2020. Diese Studie untersucht den Zusammenhang zwischen Selenstatus und COVID-19-Verläufen in China.

Further reading

• Combs, G. F. „Selenium in Global Food Systems.“ British Journal of Nutrition, 2001. Ein Überblick über die Bedeutung von Selen in globalen Ernährungssystemen.
• Schrauzer, G. N. „Selenium and Selenium-antagonistic Elements in Nutritional Cancer Prevention.“ In Critical Reviews in Biotechnology, Band 29, Nr. 1, 2009. Diskutiert die Rolle von Selen in der Prävention von Krebserkrankungen.
• Hoffmann, Peter R., und Berry, Marla J. „The Influence of Selenium on Immune Responses.“ In Molecular Nutrition & Food Research, Band 52, Nr. 11, 2008. Diese Veröffentlichung erforscht den Einfluss von Selen auf das Immunsystem.