Nutrization: Nutrition, Supplements and Herbs

Conjugated linoleic acid (CLA) is a natural occurring fat that may reduce hunger and increase the fat burning rate of the body. CLA changes the way fat is absorbed such as inhibiting fat absorption in the intestines and increases enzyme activity to transport fat into the mitochondria to be burned as fuel.

Linoleic acid itself comes from meat and dairy products. CLA is both trans fatty acid and a cis fatty acid. A fat that is an altered form of omega-6 free fatty acids. It is an isomer of linoleic acid where it contains the same atoms and molecules of linoleic acid but the structure is different. It is Conjugated. Conjugated is a type of attraction between atoms and molecules that alternate double and single bonds making the electrons belong to the group of atoms and not just to a single atom. Even though CLA is partly a trans fat it is really not considered a trans fat because it is naturally conjugated. Not the synthetic hydrogenated unsaturated fat but a natural trans fat.

There are so many studies found on CLA today.

In the British Journal of Nutrition, researchers in Barcelona, Spain said that supplementing with Tonalin CLA with skimmed milk helped reduce body fat mass (BFM). In the study, 60 overweight but otherwise healthy men and women, aged 35 to 65 years, were randomized to a daily intake of 500 ml skimmed milk fortified with three grams of Tonalin CLA or a placebo over a 12-week period. The results showed a significant three percent reduction of BFM in the overweight group taking the milk fortified with Tonalin CLA. No significant fat loss was found in the group taking the placebo. The research also found that CLA supplementation was not associated with any adverse effects or clinical changes.

Studies have shown to decrease fat and increase lean mass in several animal studies. Effects were examined of a low concentration of either safflower oil as control (0.5%) or mixed isomers of CLA (0.4%) along with treadmill exercise on body composition in male mice fed a high-fat diet.” CLA consumption lowered fat mass and a combination of CLA and exercise decreased fat mass even further. Lean mass did not increase with exercise alone but increased significantly due to the combination of CLA and exercise. Also, serum insulin, glucose, tumor necrosis factor and interleukin-6 were lower in CLA-fed mice. “the combination of dietary CLA and exercise decreased fat mass and increased lean mass in mice fed a high-fat diet” (Journal of Nutrition 135(5):1124-1130, 2005).

In an hamster study evidence was shown that CLA could also cause too much cholesterol in the bile or biliary lithiasis. As quoted from Nutrición Hospitalaria, Madrid; CLA did significantly reduce total serum cholesterol (-18%) at the expense of c-LDL (-66%), and it also significantly reduced hepatic content of free cholesterol (-26%), without changes in esterified cholesterol. Besides, CLA produced a 32% increase in biliary cholesterol concentration, a 28% increase in Lithogenic Index, and a higher incidence of biliary lithiasis. Therefore, the present study shows that the CLA trans-10,cis-12 isomer is hypercholesterolemic since it increases, at least in part, cholesterol secretion to the bile. As a consequence, this effect increases the risk for biliary lithiasis (Conjugated linoleic acid lowers hypercholesterolemia but increases the risk for biliary lithiasis”. Nutr Hosp, 2008).

So, yes, CLA has been shown to reduce fat. Some animal studies have shown changes that may be good and bad. As for humans evidence is still in favor of taking CLA. Some studies on humans have claimed that with exercise there is an increase in muscle. However, this claim may have not been very popular among bodybuilders at one time because the muscle gains and fat loss were not fully noticed until after taking CLA for several months; because some bodybuilders may have wanted a more instantaneous effect from a supplement.

An article in FLEX, “The skinny on CLA: a once-popular fat-loss supplement makes a comeback, and for very good reason–it works.(NUTRITION) “ The authors of Flex gave recommendations of what CLA product to take. Look for CLA products that provide cis-9, trans-11 CLA and trans-10, cis-12 CLA isomers. (These forms were used in studies that showed positive benefits.) Take one to three grams of CLA with breakfast, lunch and dinner. Start with a lower dose and work up as you find you tolerate it well. Give it at least three months to see results, although you may start to see positive improvements in as little as four weeks. CLA–it may not be the most riveting fat burner on the market, but for those with a little patience, it could prove to be one of the best (Jim Stoppani. Flex. July 2008 v26 i5 p242(4).)