Biologische Wirksamkeit von konjugierten Linolsäuren

Zusammenfassung

Konjugierte Linolsäuren (CLA) sind im Gegensatz zu Linolsäure hauptsächlich in tierischen Produkten wie Fleisch, Wurst, Milch oder Milchprodukten zu finden. Für CLA werden verschiedene biologische und physiologische Wirkungen diskutiert, die jedoch hauptsächlich auf Zell- und Tierebene gezeigt wurden. Dies gilt vor allem für ihre antikarzinogene Wirkung, die mit beiden Systemen bestätigt wurde. Verschiedene Studien an Tieren zeigen antithrombotische, aber auch prothrombotische Effekte von CLA. Weiters gibt es im Tierversuch Hinweise auf eine antidiabetogene Wirkung. An Tiermodellen, vereinzelt auch schon in Humanstudien, konnte eine Reduktion des Körperfettanteils und eine Induktion der mageren Körpermasse gezeigt werden; die Ergebnisse im Humanbereich sind jedoch widersprüchlich und basieren auf kurz- und mittelfristig angelegten Studien. Daten von Langzeitinterventionen fehlen ebenso wie eine gesicherte Risikoabschätzung, trotz der Tatsache, dass erste Daten zur Sicherheitsbeurteilung kürzlich publiziert wurden. Bis heute gibt es Hinweise auf vielfältige protektive Effekte von CLA vor allem in Zell- und Tiermodellen, jedoch müssen Langzeitinterventionsstudien an Menschen diese positiven Wirkungen noch nachhaltig bestätigen.

Summary

In contrast with linoleic acids, conjugated linoleic acids (CLA) are mainly found in animal products such as meat, milk or milk products. Different biological and physiological effects are attributed to CLA which, however, could only be demonstrated in cell and animal studies. In particular, anticarcinogenic effects were found in both systems. Several animal studies resulted in both antithrombotic and prothrombotic effects. In addition, antidiabetic effects were found. Mainly the results of animal studies, but also those of some human studies, indicate that CLA also reduces the overall fat content and increases the lean body mass. However, these results, particular of human studies, are controversial and only based on short-term studies. Data on long-term studies are missing as are safe risk assessments even though first safety assessments have been published recently. Multiple protective effects of CLA, especially those found in cell and animal studies, are assumed, but positive effects on humans will have to be confirmed by long-term studies.

Schlüsselwörter

Konjugierte Linolsäuren - Zell- und Tierstudien - biologische Effekte - Sicherheit

Key words

Conjugated linoleic acid - cell and animal studies - biological effects - safety assessment

Literatur

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1 LD50 = Letaldosis 50; Dosis, die bei der Hälfte der Tiere tödlich wirkt; jeder LD50-Wert gilt nur für die jeweilige Tierart und den jeweiligen Applikationsweg.