CLA Has Mixed Effect on Oxidation

CAMPINAS, BrazilThe effect of conjugated linoleic acid (CLA) on oxidation is inconclusive, as researchers showed different CLA supplements and methods of measuring in vivo oxidation can produce either positive or negative results. In a study published in the July issue of Lipids (Epub ahead of print; 2007, July 31), scientists from University of Campinas detailed their investigation of CLA on the process of lipid autoxidation in rats. Sixty rats were divided into six treatment groups: control, control plus vitamin E (CE), CLA1 (as CLA One®, from PharmaNutrients), CLA One plus vitamin E (CLA1E), CLA2 (as AdvantEdge® CLA, from EAS), and AdvantageEdge plus vitamin E (CLA2E). The animals were supplemented for 42 days. Peroxide, malondialdehyde (MDA), 8-iso-PGF2(alpha) isoprostane and catalase were measured as indicators of lipid autoxidation.

Hepatic peroxide test results indicated CLA increased oxidation: values for CLA-supplemented groups, particularly group CLA1, were higher than those of the control group. However, serum MDA results showed CLA reduced oxidation in groups CLA2 and CLA1, as compared to the control group. Tests for serum catalase indicated a reduction of oxidation, primarily in groups CLA2 and CLA1; these values were significantly lower than those of the control group. An increase in 8-iso-PGF2(alpha) in urine was also observed, particularly in group CLA2, compared to the control group. The researchers concluded the influence of CLA on lipid autoxidation is dependent on supplement type, supplement dosage and chosen indicator, including its tissue and determination methodology.

http://www.springerlink.com/content/1558-9307