Does Conjugated linoleic acid (CLA) have any bad side effects? Does it work for weight loss? CLA has been sold for many years as a fat loss supplement based on the weight loss and body composition (i.e. losing fat and gaining muscle) changes seen in studies using mice and rats. Does is work in humans? More recently research in humans has shown that it can be used to increase fat loss. In this article we'll look at some of the benefits of CLA as well as some of the potential side effects. In addition to weight loss studies there have been (and are currently) countless studies looking at the effects of this fatty acid on reducing inflammation, fighting cancer, and in the treatment of other conditions.
Ever since 2007, there has been an increase in use of CLA as a fat burner. This is due to the release of a meta-analysis (basically a review of several scientific studies) published in the May 2007 issue of the American Journal of Clinical Nutrition which concluded that 3.2g/d of CLA can induce moderate weight loss in humans. CLA is an attractive weight loss supplement and many people use conjugated linoleic acid as part of a fat loss supplement stack (i.e. a group of compounds and herbs taken together to maximize effects) because unlike many other weight loss supplements it is not a stimulant and you don't suffer the nasty side effects of getting the jitters, increased heart rate, or worse - increased blood pressure. This is especially as there are not many effective options for non-stimulant fat burners on the market.
Let's now look at two more studies that involve people taking supplemental CLA. The first study was again published in the American Journal of Clinical Nutrition. The researchers found that when people supplemented with 3.2 g/d of CLA (this is generally the recommended dosage for weight loss purposes) they burned more fat and more specifically they burned more fat when they slept!
This is true.
Not only did the subjects that took CLA burned more fat when they slept, the fat they burned was NOT fat they had recently eaten; it was actually stored body fat that they were burning. This study gets even better as the researchers reported that the individuals that took CLA had decreased urinary protein losses. In other words the CLA group had improved protein retention when they slept. These are really interesting findings. If I owned a supplement company that sold large dosages of CLA - my new headline would be "CLA - Scientifically Proven to Burn More Body Fat and Build Muscle while you SLEEP."
So CLA can work for weight loss but are there any side effects? Again in 2007, another study was published that looked at the effects of CLA on weight loss, this time in obese people. In this study, the participants were given CLA dosages of 0, 3.2, or 6.4 grams/day. At the end of the study the group that received the 6.4 g/d of CLA experienced a significant increase in a compound called C - reactive protein or CRP for short. C - reactive protein is a protein that is released from your liver. It is commonly used in the medical field as a general marker of the level of inflammation in your body - higher CRP means more inflammation.
While there was an increase in CRP, it was truly not clinically significant as CRP levels remained below what is considered normal (Normal CRP levels are 3mg/dL). It is also important to see realize that the people in the study that had increased CRP as a result of taking a CLA supplement were taking 2x the 'recommended' dose for weight loss and also that people that obese normally have higher CRP levels (this might have come into play here as well). The group that only took 3.2 grams per day did not have any increase in their CRP levels.
Based on the findings in the studies that I've mentioned above and the review of studies from article in the American Journal of Clinical Nutrition is seems that 3.2 g/d of CLA can be safely taken to boost weight loss.
The next question that you should ask is...
What do you do with these findings? At the moment not a whole lot... CLA is a nice add-on to a fat loss program but "add-on" is the key word. CLA is perfect for nutrient stacking as combing these effects with a supplement like green tea extract (which has also been shown to boost weight loss), increased non-exercise physical activity, and multiple meals throughout the day will surely boost your fat loss. If you aren't spot on with your nutrition, training with weights 3x per week, and doing 3 interval sessions per week then don't waste your time with CLA and focus on the more important things.