Conjugated Linoleic Acid (CLA) for Weight Loss

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Conjugated Linoleic Acid, known as CLA, is a slightly modified form of the unsaturated, omega-6 fatty acid called linoleic acid. Going mainstream more than a decade ago, CLA has become well-known as a fatty acid that may help with efforts to lose fat. 

What Does CLA Do?

In the 1980s, Dr. Michael Pariza, working at the University of Michigan, discovered that that CLA could affect body fat levels by reducing fat storage sites, and helping increase lean body tissue. The primary promotion of CLA, however, has been the claims that it can reduce the number and size of fat cells, help reduce the activity of enzymes that store fats, help speed the disintegration of fat cells, and help fat burn faster. 

Despite the research, scientists don't definitively understand how CLA works. Experts theorize, however, that CLA may block fat cells from increasing in size by affecting enzymes that contribute to fat storage.

Which Foods Are the Best Sources of CLA?

CLA is found in the following foods, at higher concentrations:

  • Beef
  • Butter
  • Colby cheese
  • Cottage cheese
  • Ground turkey
  • Homogenized milk
  • Lamb
  • Safflower oil
  • Sunflower oil
  • Sour cream
  • Swiss cheese
  • Veal
  • White button mushrooms
  • Yogurt

Like many healthy substances, the best, and most bio-available, way to take advantage of CLA is through its natural form in food products. The challenge, however, is that some of the most CLA-rich foods are high-calorie, not heart-healthy, and high in harmful fats. So some people prefer to take CLA supplements.

Is CLA Safe?

The FDA categorized CLA as GRAS (Generally Recognized as Safe) in 2008.

Is Any Brand of CLA Good to Use?

Different brands have different amounts of active CLA. A number of the research studies that established the effectiveness of CLA used a patented form of CLA known as Tonalin. Tonalin's patented formula for CLA can be found in a number of brands of CLA, including brands such as Natrol, Jarrow Formulas, and Nature's Way, among others.

Is CLA Safe to Take With My Thyroid Medications?

There's no evidence that CLA, a food supplement, interacts with thyroid medications, or poses any special dangers to thyroid patients. But you should always discuss any supplements you intend to take with your own physician or practitioner before starting.

Is CLA Only for People with Thyroid Problems?

The studies have shown that CLA may be effective for reducing/converting fat. You don't have to have a thyroid problem to potentially benefit from CLA.

How Much CLA Should You Take?

Some studies have shown that a minimum daily dosage of 1.7 grams (1,700 mg) is generally recommended, but some experts suggest from 3 to 3.5 grams (3,000 to 3,500 mg) daily is the optimal level for fat-burning benefits. Since various formulations contain different amounts of CLA, it's wise to take a pure CLA supplement or make sure you are getting the right levels from combination supplements.

Does CLA Have Soy in It? Should You Take It If It Contains Soy?

Some CLA supplements contain soy or soybean oil. If you have a thyroid condition, you may want to avoid CLA supplements that contain soy or soy products.

How Should You Take CLA?

The various recommendations differ here. Some recommendations suggest to take it before eating. Others suggest to take it with meals. The Natrol web page for their Tonalin CLA product says to take it preferably with low-fat or nonfat milk for maximum protein absorption. 

Does CLA Have Any Side Effects?

A subset of people reports feeling slightly nauseous after taking CLA supplements, or isolated cases of gastrointestinal upset or loose stools. These side effects typically are reduced when the supplements are taken with protein (i.e., with milk), and usually decrease after about 2 weeks taking the supplement.

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