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Conjugated fatty acids in beef: can they help to fight cancer?
A joint INRA-INSERM-ADIV research programme has made it possible to demonstrate the anticancer properties of fatty acids in beef, and especially CLA (Conjugated Linoleic Acid), which are polyunsaturated fatty acids with conjugated double bonds. This work was carried out by the Herbivore Research Unit at the INRA Centre in Theix, in collaboration with INSERM Unit 484 in Clermont Ferrand, in the context of a thesis project; it suggests a more positive role for beef in terms of its possible effects on consumer health.
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Improving the health value of products is one of the principal research themes at INRA. A programme implemented by the Herbivore Research Unit at Theix, in collaboration with INSERM Unit 484 in Clermont-Ferrand and with support from the ADIV (the French Association for Development of the Meat Industry), representatives from the cattle industry (INTERBEV) and OFIVAL (National Office for Meat and Animal and Poultry Breeding), has produced some promising results which throw new light on the value of beef, which was considered with suspicion during the outbreak of mad cow disease.
More specifically, the aim of this work was to demonstrate the health value of some of the fatty acids present in small quantities in meat from ruminants: polyunsaturated fatty acids with two conjugated double bonds, or CLA (Conjugated Linoleic Acid), as a function of livestock breeding practices (notably diet) and the technological processes (maturing and cooking) applied to the meat produced. The objective was to compare the relative cytotoxic potential of different CLA isomers in beef against human tumour cells, in order to identify those with the most marked anticancer properties.
The CLA content in beef is directly proportional to the level of neutral lipids (principally triglycerides) present. However, from a nutritional point of view, if the proportion of CLA in meat is considered with respect to other fatty acids, the data differ. Indeed, animal diet markedly modulates the levels of CLA and its isomers in meat. Thus, supplementing animal feed with oilseeds containing high levels of polyunsaturated fatty acids (such as linseed or sunflower) significantly increases the proportion of CLA versus other acids in the muscles. However, this variability is also strongly linked to the type and age of the animal, other components in its diet (hay/concentrate ratio) and also the muscle type and metabolic activity of its fibres.
The anticancer properties of different CLA isomers and their conjugated derivatives, all naturally present in beef, were studied in an in vitro culture model of human tumour cells (lung, breast, colon, prostate, ovary) or normal cells (fibroblasts). The cytotoxicity of each CLA isomer or its conjugated derivatives was determined by quantifying cellular DNA after 48 hours of incubation.
When tested separately, the different CLA isomers all exhibited cytotoxic activity against cancer cell lines, with the 9trans,11trans isomer being endowed with the most marked activity. However, when CLA extracted from beef were tested in a mixture (all CLA isomers present naturally in the meat), the degree of their cytotoxic effects was mainly linked to the proportions of different CLA isomer families: a high proportion of cis-trans isomers associated with a low proportion of cis-cis and trans-trans isomers produced the most marked cytotoxic activity. These results suggest that it is important to take account not only of the quantity of CLA present in meat, but also of the distribution and possible interactions between different isomers and other fatty acids in meat to potentiate their possible biological properties. It is nonetheless important to remain cautious when trying to extrapolate these results because at present, no data are available concerning the in vivo anticancer effects of CLA from beef, particularly in humans.
In conclusion, studies to characterise CLA content and composition in tissues from bullocks and cull cows need to be pursued, with particular emphasis being placed on other types of cattle (heifers, bull calves, etc.). This should make it possible to develop a tool which can model variations in the CLA distribution in cattle muscle as a function of the type of animal, type of muscle and type of diet. Furthermore, it is essential to determine the anticancer activity of other fatty acids present in beef, and to confirm the results of our studies by verifying in vivo that the CLA in beef exhibit a specific, preventive and/or curative anticancer activity.
Scientific contacts:
D.Gruffat and D. Bauchart,
Unité de Recherches sur les Herbivores, Centre de Recherches Clermont-Fd-Theix, France
gruffat@clermont.inra.fr; bauchart@clermont.inra.fr
tel : +334 73 62 42 56 et +334 73 62 42 21
fax : +334 73 62 46 39
Equipe Nutriments et Métabolismes
Unité de Recherches sur les Herbivores
Centre de Clermont-Ferrand / Theix
63122 St-Genès-Champanelle, France
Web site : www.clermont.inra.fr/urh/
For further information:
- De La Torre A., Debiton E., Gruffat D., Durand D., Barthomeuf C, Peyron A., J.M. Chardigny, Bauchart D. 2003. Action cytotoxique des CLA et de leurs dérivés conjugués sur différentes lignées tumorales humaines. Proceedings du 1er Congrès de la Société Française de Nutrition, Clermont Fd, 17-19 Novembre 2003, p 87. site : www.inra.fr/sfn
- Bauchart D., Gladine C., Gruffat D., Leloutre L., Durand D. 2004. Effects of diets supplemented with oil seeds and vitamin E on specific fatty acids of rectus abdominis muscle in Charolais fattening bulls. Proceedings du Congrès de la FEZ, 7-10 Septembre 2004, Bled, Slovénie.
- De La Torre A., Debiton E., Durand D., Chardigny JM., Berdeaux O., Loreau O., Bartomeuf C., Bauchart D. Gruffat D. 2005. Conjugated linoleic acid isomers and their conjugated derivatives inhibit growth of human cancer cell lines. Anticancer Research, 25 : 3943-3950
- De La Torre A., Debiton E., Juanéda P., Durand D., Chardigny JM., Bartomeuf C., Bauchart D. Gruffat D. 2006. Beef conjugated linoleic acid isomers reduce human cancer cell growth even when associated with other beef fatty acids. British Journal of Nutrition, 95 : 346-352
- De La Torre A., Gruffat D., Durand D., Micol D., Peyron A., Scislowski V., Bauchart D. 2006. Factors influencing proportion and composition of CLA in beef. Meat science, 73 : 258-268
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Rédacteur :
INRA / DPE
Rubrique :
Laboratories – research results
Date of creation : 14/11/2006
Date of last update : 14/11/2006
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