What role does Selen play in Langlebigkeit?

Selenium is an essential trace element that, as a component of selenoproteins (e.g., glutathione peroxidases, thioredoxin reductases), plays a key role in antioxidant defense and thyroid function. These functions could theoretically contribute to longevity by reducing oxidative stress and supporting DNA repair. However, the evidence for a direct extension of lifespan through selenium supplementation is weak. Observational studies show mixed associations, and randomized controlled trials have not demonstrated clear benefits for healthy adults. Moreover, the safe dosage range is narrow: excessive intake (>400 µg/day) can be toxic (selenosis). Genetic variants such as in the GPX1 gene (rs1050450) affect selenium utilization, but the effects are small and not clinically relevant. For longevity, a balanced diet providing adequate selenium (e.g., from Brazil nuts, fish, eggs) and a healthy lifestyle are more important than isolated supplements. Consumer DNA tests for GPX1 do not provide actionable guidance for selenium dosing. Conclusion: avoid selenium deficiency, but do not supplement at high doses without medical advice.