CLA (Conjugated linoleic acid)

Conjugated linoleic acid is a trans fat, though some researchers claim that it is not harmful in the same fashion as other trans fatty acids, but rather is beneficial. [citation needed] CLA is a conjugated system, and in the United States, trans linkages in a conjugated system are not counted as trans fat for the purposes of nutritional regulations and labeling. Unlike most trans fatty acids found in the human diet, CLA occurs naturally, produced by microorganisms in the fore-stomach of ruminants. Non-ruminants, such as humans, may be able to produce some isomers of CLA from non-conjugated ruminant fats. One such example is vaccenic acid, which could be converted to CLA by delta-9-desaturase.

CLA comes in two isomers: the c9,t11 isomer (rumenic acid) which appears responsible for improving muscle growth,[citation needed] and the t10,c12 isomer which primarily prevents lipogenesis (storage of fat in adipose tissue). Most supplements sold in stores contain a 50/50 mix of both isomers.

Various antioxidant and anti-tumor properties have been attributed to CLA, and studies on mice and rats show promising results in reducing mammary, skin, and colon tumor growth; however, it is suspected that sufficient concentrations to achieve anti-inflammatory effects within human tissues may not be attainable via oral consumption. [citation needed]

Many studies on CLA in humans show a tendency for reduced body fat, particularly abdominal fat, changes in serum total lipids and decreased whole body glucose uptake. The maximum reduction in body fat mass was achieved with a 3.4 g daily dose. CLA supplementation has, however, been shown to increase C-reactive protein levels and to induce oxidative stress and to reduce insulin sensitivity and increase lipid peroxidation.

CAS registry number: 2420-56-6, Molecular Formula: C18H32O2