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Fitosteroles. Mecanismos biológicos y efectos metabólicos

fólico y vitamina B12 aumentaron significativamente.

En cuanto a los efectos sobre los carotenos, un metaanálisis (64) ha demostrado descensos en el licopeno y en los alfa y beta carotenos. No obstante, en el mismo estudio sugieren que parte de este descenso puede deberse a una reducción de la absorción intestinal de la proteína transportadora de estos carotenos, que no es otra que el LDL. En cuanto a las vitaminas A y D, no se observaron variaciones.

Con respecto a los posibles efectos sobre la vitamina K, de nuevo los resultados varían según los estudios. Mientras unos (65) muestran una disminución de las concentraciones de vitamina K dependiente de la cantidad de fitoesteroles administrada, otros (66) mostraron que los estanoles no parecen tener efecto alguno sobre los factores de la coagulación y la fibrinólisis.

Conclusiones

En los últimos años se ha avanzado mucho en la caracterización del mecanismo de acción de los fitoesteroles, llegando incluso a describirse los mecanismos bioquímicos de su acción. En cuanto a sus efectos, los estudios demuestran que consiguen una disminución eficaz de los niveles de LDL proporcional a la dosis de esteroles administrada, siendo especialmente eficaces si se toman de manera continuada y después de comidas ricas en grasas.

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