Important Weight Loss Side Effect Info about Dr. Oz Conjugated Linoleic Acid Fat Melter
Today is the day Dr. Oz begins his televised “Fat-Fighting Solutions” week with an assortment of brand new fat melters, dieting tips and exercises to help you lose weight, slim down and become healthy. In a preview of today’s show with special guest Eva Selhub, MD, Dr. Oz reveals his “newest” weight loss fat melter―conjugated linoleic acid; or, as it is more commonly known―“CLA.” However, as it turns out, CLA for weight loss is not so “new” after all and has a reputation of being among the more argued weight loss supplements that may not work in some people and in others may open them to a risk of developing diabetes.
Conjugated linoleic acid is a natural fatty acid that is found primarily in the meat of grass-fed cattle and sheep. However, because the majority of livestock today are fed grain, the levels of CLA in meat at the grocery store are much lower than what they used to be. Today, it is considered perfectly safe, beneficial and recommended by some nutritionists to get your CLA from grass-fed animals.
The FDA categorizes CLA with GRAS (Generally Regarded as Safe) status for certain foods including fluid milk, yogurt, meal replacement shakes, nutritional bars, fruit juices and soy milk. A natural non-meat source of CLA can be gained in appreciable concentrations by eating some species of mushrooms.
However, in its supplement form, the important isomers (types of CLA), efficacious dosages, benefits and potential health risks of ingesting supplemental CLA, are far less clear. As expected, this lack of clarity does not stop sellers of this supplement from claiming supporting studies regarding its fat melting abilities in their advertisements while ignoring contrary studies that report no benefit and some potential harm.
Interest in CLA began a number of years ago when researchers reported fat loss in some species of laboratory animals that were fed conjugated linoleic acid. In humans, a 2004 study by Scandinavian scientists reported in The American Journal of Clinical Nutrition their results that demonstrated study participants who were overweight had reduced their body fat mass by as much as 9% while taking CLA.
A following study in 2006 by researchers from the University of Wisconsin-Madison published more modest results from taking CLA in a supporting article in the International Journal of Obesity where they reported that CLA causes weight loss in humans. In their study consisting of 40 overweight―but otherwise healthy―men and women, who were given either 3.2 grams of CLA or a placebo per day for 7 months, the CLA reduced body fat mass by 2.2 lbs. and body weight by 1.3 lbs., whereas the placebo group gained 1.5 lbs. of body fat mass and 2.4 lbs. of body weight during the study.
More recently, however, other studies do not find that conjugated linoleic acid does reduce fat mass and/or result in weight loss. In a 2011 cross-over study published in the Journal of Nutrition consisting of three 8-week phases that looked at weight and blood-fat regulation in 27 participants who were overweight and had high blood-fat levels, no beneficial effects toward weight loss or blood-fat were seen when given either of two formulations of CLA compared between each other and with a safflower oil control.
As for negative health effects of taking CLA supplements, there are reports of typical general abdominal distress experienced by some people who take CLA supplements. However, much more alarming are past studies that have reported that treatment with some dietary formulations of conjugated linoleic acid causes isomer-specific insulin resistance in obese men with metabolic syndrome. In other words—CLA supplements taken for weight loss may induce diabetes in some patients. And because of this, a significant number of health web sites caution against taking CLA supplements.
In a 2012 study published in the Journal of Nutrition and Metabolism, researchers found that at least some forms of conjugated linoleic acid are associated with lipodystrophy in addition to insulin resistance, hyperinsulinemia, and hyperglycemia in mice. Furthermore, other studies have reported that taking CLA may decrease “good” HDL cholesterol levels in people who take some CLA supplements.
Aside from claims made by televised health shows and supplement websites, none have shown or referenced clearly proven studies that significant weight loss or loss of abdominal fat is achievable with taking conjugated linoleic acid supplements. At best, if the studies that report seeing some fat melting results are accurate, the loss is minimal over what amounts to taking a relatively expensive supplement for long periods.
In addition, experts on CLA admit that not enough is known about the association of developing diabetes with CLA and whether it is dependent on the type of CLA taken, its dosage, health of an individual before taking CLA or how closely results from animal studies apply to humans. And, some studies report not observing this effect in their subjects. However, in the most recent study available published in 2012 in The American Journal of Clinical Nutrition, researchers report that CLA may indeed be involved in insulin regulation. And therefore, concerns of a risk of developing diabetes from taking a conjugated linoleic acid supplement may have some merit and should be avoided until more is known.
For informative articles about previous Dr. Oz fat melting supplements, follow these links to two articles titled, “New Fat Busting Antioxidant Supplement on The Dr. Oz Show Allows a High Fat Diet” and “Three New Belly Fat Busting Supplements for the New Year.”
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The Dr. Oz Show— “Brand New Fat Melters”
“Conjugated linoleic acid supplementation for 1 y reduces body fat mass in healthy overweight humans” The American Journal of Clinical Nutrition (June 2004) vol. 79 no. 6 1118-1125; Jean-Michel Gaullier et al.
“The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain” International Journal of Obesity (2007) 31, 481–487; A C Watras et al.
“Treatment with dietary trans10cis12 conjugated linoleic acid causes isomer-specific insulin resistance in obese men with the metabolic syndrome” Diabetes Care (2002) Sep. 25(9):1516-21; Riserus, U. etal.
“Conjugated Linoleic Acid Supplementation for 8 Weeks Does Not Affect Body Composition, Lipid Profile, or Safety Biomarkers in Overweight, Hyperlipidemic Men” The Journal of Nutrition July 1, 2011 vol. 141 no. 7 1286-1291; Shama V. Joseph et al.
“Dietary Conjugated Linoleic Acid and Hepatic Steatosis: Species-Specific Effects on Liver and Adipose Lipid Metabolism and Gene Expression” Journal of Nutrition and Metabolism 2012; Diwaker Vyas et al.
“Cross-sectional study of conjugated linoleic acid in adipose tissue and risk of diabetes” The American Journal of Clinical Nutrition July 2012 vol. 96 no. 1 175-181; Nelsy Castro-Webb et al.