Suplimentarea cu seleniu

Ce este seleniu?

Seleniu este un mineral care se gaseste in alimente precum nuci, paine, grane, carnuri, peste si oua. Este un micronutrient esential, pentru ca nu poate fi luat decat prin dieta, corpul nu il poate produce singur. 

Seleniul se leaga de aminoacidul cisteina cand ajunge in corp si formeaza selenoproteine. Selenoproteinele au roluri esentiale in multe procese organice, precum functionarea glandei tiroide si functiilor imunologice, sanatate reproductiva si sinteza ADN. 

Pana in 1957 se credea ca seleniu este toxic pentru oameni si ca ar trebui evitat complet. Acum stim ca este un nutrient vital sanatatii umane. Dar da, este posibil sa consumi prea mult seleniu si sa devina toxic, asa ca este important sa ai un consum adecvat de seleniu, nu neaparat mare! 

Beneficiile seleniului

Sa ai un aport adecvat de seleniu te poate ajuta cu:

• Tratarea preeclapsiei.
• Mentinerea functiilor cognitive pe masura ce imbatranesti.
• Scaderea riscului de cancer.
• Reducerea riscului de proliferare a cancerului de prostata. 
• Imbunatatirea productiei spermei.
• Reducerea riscului de avort spontan. 

Dar multe din aceste afirmatii sunt bazate pe studii observationale (care arata corelatii dar nu cauzalitati) si unele din ele au fost contestate de alte studii.

Dar se stie cu certitudine ca un aport adecvat de seleniu este legat de: 

• Reducerea inflamatiilor cronice.
• Reducerea stresului oxidativ. 
• Imbunatatirea functiilor tiroidei.
• Imbunatatirea imunitatii.
• Imbunatatirea starii de spirit si reducerea anxietatii.
• Imbunatatirea functiilor cardiace. 

Efectele secundare ale consumului excesiv de seleniu

Luat in dozlele recomandate seleniul nu are efecte secundare. 

Dar, sa ingerezi cantitati prea ridicate de seleniu, fie prin dieta, fie prin suplimentatie (sau o combinatie intre ele), poate sa  prezinte riscuri. 

Efectele secundare ale consumului prea mare de seleniu includ:

• Cresterea riscului de aparitie a diabetului la barbati.
• Posibila descrestere a hormonului tiroidian T3 la barbati.
• Posibila crestere a colesterolului rau, LDL, dar si colesterolului total si a colesterolului bun HDL.

Intoxicarea cu seleniu are loc la doze foarte mari si prezinta simptome precum:

• Dureri de stomac.
• Oboseala.
• Dureri articulare.
• Decolorarea pielii.
• Unghii fragile (pete albe pe unghii si dungi longitutdinale pe suprafata lor)
• Caderea parului.
• Respiratia miroase a usturoi.
• Senzatie de greata si/sau voma.
• Diaree.
• Edem pulmonar. 
• Tremur si spasme musculare. 
• Neliniste. 
• Confuzie si delir.
• Coma.

Doza maxima tolerabila la adulti este de 400 mcg/zi. Cu alte cuvinte, mare parte din adulti pot consuma pana la 400 mcg pe zi de seleniu fara efecte negative.

Dozele zilnice recomandate de seleniu

Doza zilnica recomandata de seleniu este de 55 mcg, dar studiile care analizeaza efectele suplimentarii cu seleniu folosesc doze mai mari de atat.

Aportul general de seleniu al populatiei variaza mult si depinde foarte tare de solul in care au crescut alimentele pe care le consuma. Cum consumul excesiv de seleniu poate fi toxic este bine sa fii precaut, asa ca 55-60 mcg/zi de seleniu este suficient. 

Din pacate in zilele noastre alimentele sunt mai sarace in nutrienti, inclusiv seleniu, asa ca deseori este necesara suplimentarea. 

Suplimentele cu seleniu contin doze foarte mari, care nu sunt neaparat necesare. Asa ca poti imparti in doua pastilele sau poti lua un complex de minerale care contine si seleniu, cantitatile fiind mai mici cand vine combinat cu alte minerale. 

Referinte

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