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
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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.
Dr. Karl-Heinz Wagner
Institut für Ernährungswissenschaften der Universität Wien
Althanstraße 14
A-1090 Wien
Email: karl-heinz.wagner@univie.ac.at
