Conjugated Linoleic Acid (CLA) is a naturally occurring trans-fatty acid that is a member of the omega-6 family of essential fatty acids. Essential meaning that your body can’t make it so you must get it in your diet. As an essential fatty acid, CLA has a number of health benefits. The CLA family of fatty acids is made up of at least 28 isomers. An isomer has the same chemical formula but has different structure. Of the 28 isomesr, there are two isomers that are particularly important for humans known as c9t11 and t10c12 as they carry biological activity.
Scientific studies indicate that CLA has the ability to decrease body fat, increase lean muscle, lower blood pressure, boost the immune system, fight cancer, improve insulin sensitivity and prevent heart disease.
In clinical trials it has been found that overweight individuals who were given 3.4 gm of CLA daily for 2 years had reduced body fat and that CLA helped to maintain weight for long-term. Another study where individuals put on 4.2 gm of CLA daily were found to lose body fat with no real reduction in weight. You can conclude from this that these individuals improved lean body mass with fat loss meaning overall no weight was lost. You’re trading fat for lean muscle. Another study demonstrated similar findings with a decrease in fat without a change in weight. In this case, patients took 1.8 mg of CLA daily. This demonstrates that CLA can improve overall body quality.
Studies done on the effect CLA insulin are not clear. Some studies were done on humans and others on rodents. Rodent studies indicate that CLA has anti-diabetic properties while some studies on humans indicate that CLA may promote insulin resistance and contribute a worsening of pre-existing diabetic conditions. It turns out that the two biologically active forms can work in opposition to each other. Meaning one can promote insulin resistance and the other increases insulin sensitivity. You have to keep in mind that they differ in structure so that imparts a different function.
CLA has been reported to be a powerful antioxidant, however some studies demonstrate an increase in lipid peroxidation with an increase in inflammatory markers in obese men. Another study demonstrated elevated C – reactive protein levels with increased oxidative stress. But, again this was isomer dependent. Isolated isomers of CLA are not widely available, so you need to consider any negative effects certain CLA isomers can produce and choose your supplement wisely. Ideally, your supplement should contain 70 to 80 percent of one of the biologically active isomesr that is to say c9t11 or t10c12. Nevertheless, 20 to 30 percent will be other isomeric forms.
CLA is reported to have anti-cancer effects. These studies were done on rodents so how this might affect humans is not known. There certainly is great potential here but further research will be necessary to sort out the details.
Patients have reported changes in appetite while taking CLA. Individuals have reported less craving for food with an increase in feeling full. So far, this hasn’t been correlated with a reduction in energy intake or weight change.
At any rate, research is indicating that 3 to 4 grams a day is a functional dose that over the long-term will help you to burn fat and build lean muscle.