Yet another scientific study confirms that CLA is effective. A new Spanish double-blind randomized study has shown that 3 g of CLA daily given to a group of healthy, overweight persons, reduced their amount of fat and their weight over a period of 24 weeks.
In the study, the researchers wanted to investigate the efficacy and safety of a daily supplement of 200 ml skimmed milk fortified with 3 grams of CLA. The CLA consisted of the isomers C9-T11 and T10-C 12 in equal amounts.
A total of 42 overweight persons aged from 30-55 years attended the study. Their BMI was between 27 and 30, where 30 is the limit for obesity. Out of 42 participants 22 got CLA while 20 participants in the control group received placebo in the form of oleic acid, which is a non-essential fatty acid known as omega-9. The participants were informed that they should keep their habitual diet and not change their exercise habits during the investigation period.
It works and is well tolerated
After 24 weeks, the researchers evaluated the results. A total of 38 persons completed the study as four persons in the control group withdrew. The group that had received CLA had lost about two pounds, but the group who received placebo had gained a little over 100 g weight. Thus all in all about 1 kg difference and that may not sound like much, but it must be remembered that the weight loss occurred without changes in either diet or exercise habits. Unlike a number of diet regimes, wherein the weight loss is primarily due to loss of fluid, and muscle tissue, the CLA primarily causes loss of fat and not muscle tissue. The study also showed that CLA is well tolerated. There were no significant changes in markers of liver function, cardiovascular disease, cholesterol, triglycerides, or inflammation.
Widespread overweight and obesity
Over the past 30 years, the prevalence of overweight and obesity has doubled globally. Worldwide there are now about 500 million obese adults and nearly 1 billion more who are overweight. Both overweight and obesity is a threat to health. This is where CLA enters the picture as a tool that can help these people to restore normal weight.
Different types of CLA
There have been reports of lack of efficacy of CLA that it promotes insulin resistance, cardiovascular disease and inflammation, but these reports are attributed to the use of some other CLA isomers and errors in the experimental setups. There are 28 different CLA isomers , ie . different structures of the CLA molecule, but it is the C9- T11 and T10 -C 12 -isomers that have the beneficial effects to health. The C9-T11 isomers which represent almost 90% of all naturally occurring CLA, are attributed to anti-cancer effects, while the T10-C12 isomers which is less common in nature, are attributed to the ability to increase the body's fat metabolism and improve the relationship between muscle and fat.
López-Plaza B, et al. Effects of milk supplementation with conjugated linoleic acid on weight control and body composition in healthy overweight people. Nutr. Hosp. 2013;28(6):2090-98.
Conjugated linoleic acid (CLA) is a naturally occurring fatty acid found in meat from ruminant animals and in milk, cheese and other dairy products. CLA is also an antioxidant. It is formed during the animals' digestion by an enzymatic conversion of linoleic acid from grass. The content of natural CLA in cows has decreased with the number of cows no longer fed fresh grass. This is believed to be a contributing factor to the widespread obesity in populations that the natural dietary levels of CLA has dropped.