What Is It?
Conjugated linoleic acid (CLA) is a slightly altered form of linoleic acid (LA), an omega-6 fatty acid important to human health. Omega-6 fatty acids are derived from the foods we eat (primarily from meats and dairy products). The average American ingests probably less than 1 gram of CLA a day.
Recently CLA has also become available in concentrated dietary supplement form. Extravagant claims abound for these supplements, including assertions that they can help burn fat, build muscle, and fight cancer. Although there has been promising research done over the past few decades, it has primarily been in small animals. In some studies, rats and mice fed CLA-supplemented diets experienced a reduction in appetite and in accumulated body fat. Some even experienced a reduction in tumors.
It’s unclear whether humans will experience the same benefits, however. Findings have been mixed.
In perhaps the most exciting study done so far, a team of Swedish researchers reported in December, 2000 that CLA melts away fat while boosting muscle mass. The overweight and obese participants in the study experienced a reduction in body fat while taking 3.4 grams of CLA daily for 64 days. But none of them lost weight. Many also complained of nausea and of the difficulty in taking 12 capsules daily. Only 47 of the 60 participants completed the trial
Other research, including a 2000 study of healthy women reported in the journal Lipids, has also failed to find an association between CLA supplements and a reduction in weight.
There is still too little research available to determine the risk for drug or nutrient interactions with CLA supplements.
If you’re interested in taking CLA supplements, consult your doctor.
While meat and dairy products contain CLA in natural form, high supplement doses may cause side effects and long-term health problems that have yet to be determined.