This is similar to the results of reduced milk intake and reduced breast or colon cancer. Īnother study suggests that CLA consumption reduces the risk of breast or colon cancer. Ī 2017 study found CLA supplementation has been associated with increased plasma C-reactive protein concentrations and a reduction in serum adiponectin concentrations, which indicates that CLA supplements have a pro-inflammatory effect. Although CLA has shown an effect on insulin response in diabetic rats, there is no evidence of this effect in humans. Likewise, there is insufficient evidence that CLA has a useful benefit for overweight or obese people as it has no long-term effect on body composition. A 2004 review of the evidence said that while CLA seemed to benefit animals, there was a lack of good evidence of human health benefits despite the many claims made for it. Health effectsĬLA is marketed in dietary supplement form for its supposed anti-cancer benefit (for which there is no strong evidence or known mechanism, and very few studies conducted so far) and as a bodybuilding aid. However, this bioconversion may not occur at any significant level in those with a digestive disease, gluten sensitivity, or dysbiosis. In healthy humans, CLA and the related conjugated linole nic acid (CLNA) isomers are bioconverted from linoleic acid and alpha-linolenic acid, respectively, mainly by Bifidobacterium bacteria strains inhabiting the gastrointestinal tract. Non-ruminants, including humans, produce certain isomers of CLA from trans isomers of oleic acid, such as vaccenic acid, which is converted to CLA by delta-9-desaturase. CLA and some trans isomers of oleic acid are produced by microorganisms in the rumens of ruminants. CLA is conjugated, and in the United States, trans linkages in a conjugated system are not counted as trans fats for the purposes of nutritional regulations and labeling. Unlike other trans fatty acids, it may have beneficial effects on human health. The cis bond causes a lower melting point and, ostensibly, also the observed beneficial health effects.
Ĭonjugated linoleic acid is both a trans fatty acid and a cis fatty acid. More recent studies using individual isomers indicate that the two isomers have very different health effects.
Most studies of CLAs have used a mixture of isomers wherein the isomers c9,t11-CLA (rumenic acid) and t10,c12-CLA were the most abundant. CLA is a mixture of isomers of octadecadienoic fatty acids.