CLA, short for conjugated linoleic acid, is a type of fatty acid often sold in supplemental form that is marketed as a fat-loss substance. While the evidence for CLA as a weight-loss aid is mixed, the majority of the data shows that this natural substance is safe. There are, however, some concerns for certain groups, including those with diabetes, pregnant women and children.
Present in meat and dairy products, CLA is a natural substance that may possess some health benefits, such as preventing atherosclerosis and certain viral infections. But CLA is primarily known for its proposed role in improving body composition. According to New York University Langone Medical Center, CLA is sometimes recommended for improving the ratio of muscle to fat in humans, although the evidence supporting this use is conflicting. In some studies CLA was able to reduce body fat, while in others there was no benefit observed.
Studies on Safety
A study published in 2004 in "Food and Chemical Toxicology" analyzed the safety profile of CLA in overweight individuals over a 12-month period. The study found no adverse effects associated with conjugated linoleic acid, leading the study to conclude that CLA can be safely used by obese individuals for a minimum one-year period. A study published in 2011 in "The Journal of Nutrition" concluded that although CLA showed no efficacy in reducing body weight or regulating blood lipids, supplementation was not associated with any detrimental effects.
Diabetics and Prediabetics
Overweight individuals should use caution while taking CLA. According to NYU Langone Medical Center, certain studies have found that CLA can increase insulin resistance, which can raise the risk for diabetes. Those who have diabetes should not use CLA because it may worsen blood sugar control. The medical center notes that although certain studies have found CLA to be safe for diabetics and prediabetics, people in these categories should only use CLA under the supervision of a health care professional.
Dosage and Considerations
Normal CLA doses range anywhere from 3 to 5 grams per day. Be sure to purchase CLA from a reputable manufacturer to avoid any potentially dangerous impurities. Many reputable supplements brands will be either verified by the U.S. Pharmacopeial Convention (USP verified), or they will follow Good Manufacturing Practices, a set of quality guidelines set by the National Science Foundation. Look for the seals marking these certifications. Pregnant women, young children and individuals with kidney or liver disease should not use CLA because there have been no safe dosages established for these groups.
- NYU Langone Medical Center: Conjugated Linoleic Acid
- Food and Chemical Toxicology: Safety Profile of Conjugated Linoleic Acid in a 12-month Trial in Obese Humans
- The Journal of Nutrition: Conjugated Linoleic Acid Supplementation for 8 Weeks Does Not Affect Body Composition, Lipid Profile, or Safety Biomarkers in Overweight, Hyperlipidemic Men
- WebMD: CLA: The New Miracle Weight Loss Pill?
- NSF: Dietary Supplements GMP Registration
- U.S. Pharmacopeial Convention: USP Verified Dietary Supplements
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