CLA may promote a healthier body composition.
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Like many Americans, you may take dietary supplements for their claimed health benefits. Safety is a valid concern when taking any dietary supplement. Conjugated linoleic acid is commonly found in dairy and beef and is marketed as a dietary supplement weight loss. It is not linked to reports of serious adverse effects, but consult your health care provider before taking it. CLA may cause minor gastrointestinal side effects, according to Memorial Sloan-Kettering Cancer Center.
Long-term supplementation is effective at reducing weight, according to a study in the June 2004 edition of the "American Journal of Clinical Nutrition." Based on promising results from short-term trials, researchers examined the effectiveness of CLA for reducing body weight in overweight men and women. CLA supplementation over the course of a year led to significant decreases in body fat mass, according to the study.
In another study, researchers evaluated the short-term safety of CLA at two different dosages for 12 weeks. Healthy male volunteers were divided into three groups and given 3.4 grams of CLA, 6.8 grams of CLA or placebo. Most blood safety parameters remained in the normal range among groups. By Week 12, however, the high CLA group showed elevated alanine aminotransferase. This test is used to assess abnormalities in liver function. The study concluded CLA is safe in the short term at the lower dose of 3.4 grams per day. Results were published in the 2007 issue of the "Journal of Oleo Science."
Researchers from the University of Wisconsin evaluated the long-term safety of a CLA product called Clarinol over a 12-month period. During this randomized double-blinded trial, participants took 6 grams of CLA daily throughout three phases. At the end of the study laboratory tests showed no adverse effects. This data suggests the elevated liver enzymes from the "Journal of Oleo Science" study were likely a short-term side effect. The study concluded CLA is safe for up to one year, according to the results published in the journal "Food and Chemical Toxicology" October 2004 issue.
Although there are no reported long-term safety issues, CLA has the potential to cause side effects. The "Journal of Oleo Science" study reported mild to moderate side effects linked to CLA use. About 60 percent of the group taking 3.4 grams reported side effects, as did 70 percent of the 6.8 gram group. Side effects included diarrhea, cough, nasal inflammation, mood changes, headache and fever. Most side effects disappeared after a few days, according to the study.