Conjugated Linoleic Acid

Conjugated Linoleic Acids (CLA) Supplement Profile

With the increased use of thermogenic supplements to aid people in their efforts to lose fat. Many find themselves in a predicament when it comes time to finish their diet. Conjugated linoleic acid helps with thermogenisis.

Thermogenics cause a number of beneficial effects that facilitate fat loss. However, when the supplements discontinue, the metabolic pendulum can swing back the other way. Threatening all the hard work it took to lose the fat. When it comes to ephedrine and metabolism it can be said, “what goes up must come down.”

What a person needs at that moment is something that will aid them in keeping off the fat once they finally get it off. But at the same time give them a break for the constant CNS stimulation of thermogenics. Conjugated linoleic acids, or CLA, may be just what they need.

What is it?

CLA, a naturally occurring fatty acid found primarily in beef and dairy fats. CLA formed from linoleic acid by bacteria in the gut of ruminants (cows and other herbivores with multiple stomachs). The cows then absorb the CLA and it becomes incorporated into their lipid stores, including milk lipids. We then absorb it when we eat them, or drink their milk.

Research on Cows

There is research showing that cows produce CLA endogenously as well.  Finding that as much as 64% of CLA in cows milk may be produced by the enzyme Delta-desaturase. It appears that humans also can produce CLA endogenously through similar pathways.

Science Stuff

CLA exists as several isomers (same molecule, different conformation. Kind of like your left and right hands being the same but different). Two CLA isomers (cis-9, trans-11 CLA and trans-10, cis-12 CLA) shown to exhibit strong biological activity. Appearing to exert their effects via different biochemical mechanisms (e.g. one through PPAR alpha, the other through PPAR gamma, etc). Because many isomers with seemingly different biological effects, the exact mechanisms of action still ironed out. When the exact effects of each isomers defined looks forward to much more powerful CLA supplements with more predictable effects.

How does it work?

Shown to increase certain enzymes responsible for fatty acid beta-oxidation and mobilization. Meaning that the body”s ability to mobilize and burn fat goes up with chronic CLA supplementation. Although CLA is only recently coming into its own as far as research goes, data so far points to peroxisome proliferator-activated receptor (PPAR) activity as the most probable mechanism for CLA’s effects on fat metabolism.

I’m sure many of you haven?t heard much of these receptor proteins yet, but believe me, you will soon. PPAR’s, key regulators of lipid homeostasis. Activated by a structurally diverse group of compounds including fatty acids, eicosanoids (prostaglandins), and hypolipidemic drugs. Mounting evidence indicates that PPAR’s serve as physiological sensors of lipid levels and suggests a molecular mechanism whereby dietary fatty acids (like CLA) modulate lipid homeostasis. Who knows, I might even tackle them for a future How it Work piece considering they are involved in the mechanism of action of not only CLA but also fatty acids such as flax and omega-3s For now that’s as far as we’ll go into it.

Inhibition of triglyceride uptake into fat cells

The best way to get fat is to send the fat you eat straight to the fat cell to be stored. This is generally what happens when we eat fat, however CLA supplementation has been shown to decrease the enzyme necessary for fat cells to take up fat and triglycerides from the blood.  Lipoprotein lipase activity is decreased by dietary CLA supplementation thereby decreasing the ability of fat cells to take up lipids from the blood. At the same time, Carnitine palmitoyltransferase activity is increased in both fat and skeletal muscle thereby increasing the capacity of these tissues to oxidize fatty acids. This alone could be largely responsible for the effects of CLA on body composition.

Increases insulin sensitivity

The reason CLA has been labeled a “partitioning agent” is because of its ability to increase the uptake of energy into muscle tissue and the ability to blunt energy intake into fat cells. As mentioned above, this ability to increase insulin sensitivity in muscle tissue is also attributed to CLA activity as a PPAR agonist.  So you are starving the fat and feeding your muscle, the end result being an increase or maintenance of muscle mass and a reduction in fat.

CLA acts to reduce body fat stores by chronically increasing metabolic rate.

Treatment with CLA chronically increases basal metabolic rate in test animals.  Over time this elevation leads to significant reductions in fat mass. The exact mechanism by which CLA raises energy expenditure has yet to be elucidated.

Human studies?

Before we begin I think a little disclosure is in order. Natural Ltd. ASA, the Norwegian parent company of Natural Inc., and the Wisconsin Alumni Research Foundation (WARF) hold CLA patents. WARF administers patents on the intellectual properties of the faculty at the University of Wisconsin-Madison. You see a study done in Norway or Wisconsin,  a good chance that Natural Ltd. put up some funding.

One of the first studies done on humans in Norway. Looking at the dose-response relationships of conjugated linoleic acid and body fat (BF) reductions. A randomized, double-blind study including 60 overweight or obese volunteers performed. Subjects divided into five groups receiving placebo (9 g olive oil), 1.7, 3.4, 5.1 or 6.8 g conjugated linoleic acid per day for 12 wk, respectively. Repeated-measures analysis showed that a significantly higher reduction in BFM was found in the conjugated linoleic acid groups compared with the placebo group. The reduction of body fat within the groups was significant for the 3.4 and 6.8 g CLA groups.

Doses and Body Fat

One thing that still has me confused is the lack of dose response between 3.4 grams per day and 6.8 grams per day. In animal models before this they have all shown a dose response far above 3.4 grams/day, relatively speaking. Still, there was a significant effect on body fat in all groups.

Anybody familiar with CLA research is also familiar with the name Michael W. Pariza. Pariza presented a study, performed at the University of Wisconsin-Madison, August 22nd, 2000 at the American Chemical Society Meeting in Washington, D.C.

Another Study

The study involved eighty people, placed on a diet, coupled with a moderate physical exercise program. Half received about 3 grams of CLA daily, while the others took a placebo of sunflower oil. After six months, all had lost roughly 5 pounds. There is nothing particularly astounding about that, but here is where that surprise came.

About one-third of those taking CLA actually gained muscle and lose fat, Pariza said. While those taking the sunflower oil regained their weight at a ratio of about 75 percent fat to 25 percent muscle once the study finished. People taking CLA who regained weight put on equal proportions of fat to muscle.

In Conclusion

When a person comes to the end of their diet, what they most need is for their metabolic rate to increase to accommodate the slight increase in calories that comes with maintaining one’s weight, rather than losing weight. Causing greater increase in muscle mass when the diet returns to normal. Individuals better adapted to maintain weight loss while on a normal diet. Combine this with the nutrient partitioning effects and you have a very good solution for an inevitable rebound problem.

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