ADVERSE EFFECTS OF CLA's IN HUMANS...

Possible adverse effects of CLA in humans

There are concerns that the use of CLA supplements by overweight people may tend to cause or to aggravate insulin resistance, which may increase their risk of developing diabetes . Commercially available supplements contain equal mixtures of two CLA isomers: the cis-9, trans-11 isomer (also known as rumenic acid, the predominant CLA isomer in milk and beef) as well as the trans-10, cis-12 (t10c12) isomer. All other isomers ratios found in the scientific literature are not comercially available. It is the trans-10, cis-12 isomer that is linked to many adverse side effects. Research indicates that supplementation with t10c12 CLA dramatically increases rates of oxidative stress, to levels considerably higher than that observed in heavy smokers. However, the evidence is controversial, and some studies using a mixture of c9t11 and t10c12 CLA showed no changes in insulin sensitivity. A study in 2007 use the euglycemic hyperinsulinemic clamp method which is the gold standard, to evaluate insulin resistance. The study performed in 49 obese or overweight individuals taking 3.2g CLA per day for 6 months found no adverse effects on blood glucose management. In addition, the long term studies of 1 and 2 years have found CLA supplementation to be safe with no outstanding adverse events.