Tarnopolsky (50) señala que estos dos casos no deben ser tenidos en cuenta, dado que en el primero el paciente estaba tomando además ciclosporina, fármaco con conocido efecto nefrotóxico. Además, tomaba 20 gramos de creatina al día, lo cual es una cantidad bastante superior a la recomendada.

Según Tarnopolsky, el segundo caso tampoco es representativo, dado que el paciente estaba tomando antiinflamatorios no esteroideos, que se sabe que son causantes de insuficiencia renal.

9.- “La creatina daña al hígado”. Esto se basa en que las determinaciones de AST y ALT a los atletas se suelen obtener valores mayores que en las personas sedentarias. Esto es porque en las células musculares también se presentan estas enzimas, por lo que sus niveles salen más elevados. La forma de eliminar este problema es aplicar sobre los valores de AST y ALT una corrección en relación a la cantidad de creatina kinasa (que nos puede indicar la cantidad de músculo que presenta el paciente).

Estudios en los que se han implicado otras moléculas han indicado que no existe daño en la función renal ni en otros marcadores de salud (51).

10.- “La creatina puede causar cáncer”. Existen trabajos que defienden justamente lo contrario. Por ejemplo, Patra S (52) et al obtienen como resultado de sus experimentos que la creatina es baja en los sarcomas y sin embargo aumenta cuando se produce regresión del tumor. También que la creatina puede actuar como adyuvante de algunos fármacos quimioterápicos.

Los autores que defienden la hipótesis de que causa cáncer lo hacen basándose en que la creatina contribuye a que se produzca formaldehido o amino-imidazo-azaarene en el interior de las células.

La hipótesis del formaldehido implica una acción carcinogénica de la creatina, que se ve contrarrestada por estudios como el realizado por Patra S, que indican justamente lo contrario.

La hipótesis del amino-imidazo-azaarene implica que para que se formen carcinógenos los alimentos deben ser sometidos durante largo tiempo a altas temperaturas. La creatina administrada como suplemento no pasa por este proceso, por lo que no da lugar a estos carcinógenos. De hecho, Tarnopolsky afirma que el riesgo es menor que cuando se cocina demasiado la carne de la barbacoa.

Conclusión

La creatina es un suplemento nutricional que permite mejorar el rendimiento físico y que aparentemente no entraña peligros para la salud del ser humano. Así lo afirman los resultados obtenidos en numerosos experimentos.

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