CLA from English Conjugated linoleic acids or conjugated linoleic acid is a group of linoleic acid isomers found in meat and dairy products. Conjugated linoleic acid is an isomer of linoleic acid.
In 1979, researchers at the University of Wisconsin investigated the properties of an extract of beef that was applied to the skin of mice, after which the skin was exposed to potent carcinogens. Ultimately, it was found that beef extract reduced the incidence of tumors by 20%.This meant that the extract contained anticancer agents, which turned out to be CLA, identified only in 1987 by the scientist Michael Pariza. Known for their anti-carcinogenic properties, CLA is also able to reduce the risk of cardiovascular disease as well as anti-inflammatory effects.
In recent years, the CLA has been widely used in bodybuilding. It is believed that they are able to reduce the amount of subcutaneous fat and increase the percentage of lean muscle mass. More than 30 clinical studies have been devoted to studying the effect of conjugated linoleic acid on body weight. They used various doses and regimens. As a result, a meta-analysis of the results in 2007 showed that CLA has a negligible effect on fat mass and has virtually no effect on muscle growth.
In July 2008, conjugated linoleic acid was approved by the FDA, so in the USA it can be freely added to food as a food component.
How to take CLA
The effect of CLA on fat mass is not pronounced and is manifested at a dose of at least 3.2 g per day. Average fat loss is 90 grams per week. Exceeding the indicated dose does not lead to an improvement in weight loss results. Another meta-analysis showed that conjugated linoleic acid increased lean muscle mass by an average of 1% per week. Given the simultaneous loss of fat and gain in muscle mass, total body weight may remain unchanged.
Nutritionists believe that CLA alone may not be the only solution to obesity, but in bodybuilding it can be used with some success as an adjuvant, provided that it has a general health effect, strengthens the cardiovascular system and reduces the risk of cancer or diseases.
Recently, more and more studies have appeared that disprove the effect of CLA on fat mass, possibly due to insufficient duration of intake or inaccurate measurements. One thing can be concluded for sure, if conjugated linoleic acid has a positive effect, then its level is not high.
There is evidence that an additional taken of CLA for obese people can increase insulin resistance, which increases the risk of diabetes. All sports supplements contain two CLA isomers, trans-10 and cis-12, which can enhance oxidative stress.
Another study showed that supplements with CLA increase the concentration of cholesterol in the biliary system by 32%, which can lead to the formation of stones and gallstones (cholelithiasis). Another study demonstrated a decrease in the concentration of leptin and impaired blood lipid profile. Once again, it should be noted that only very obese people have a significant health risk.
Animal studies have shown a carcinogenic effect and increased synthesis of prostaglandins with 10-trans and 12-cis CLA isomers.
CLA in products
Products, in order of decreasing concentration:
- Kangaroo meat;
- Lamb and beef (only in animals that feed mainly on grass and hay);
- Milk products;
- Some mushrooms;