Is CLA an Effective Supplement ?

There are many supplements on the market for different health and fitness goals. These include those for burning fat, gaining muscle, and general health.

One of these supplements is called CLA which is short for conjugated linoleic acid. This supplement comes from a type of oil and is said to help in the fat loss process. Is CLA an effective supplement ? Here we look at health and performance factors as well as research conducted to either prove or disprove the effectiveness of this supplement.


What is CLA ?

As stated before CLA is short for conjugated linoleic acid is an oil which is a type of trans-fat. This comes from sources such as meats and dairy products. Most if not all trans fatty acids are unhealthy and have to do with saturated fats. It has also been supposedly linked to assisting with performance in the gym concerning fat loss and possible muscle gain. The supplement is even said to have some anti inflammatory effects. Here we look at whether these claims can be proven, and if it is worth using.


Effects of CLA

There are claims that CLA has some positive effects on general health and performance. It has been thought but never totally proved that it could even have an effect on cancer. The promotion of CLA as a fat loss supplement comes from studies conducted on animals. It has been shown in animals to assist in decreasing catabolism or breakdown of muscle, promote fat loss, and even effect bone density.

Since these studies were on animals, more research should be done on the humans to see the true effects it has. One study looked at effects CLA may have on variables of resistance training. These being mainly body composition and strength. Trained subjects were given CLA for four weeks. Body composition and strength were measured before starting. The results revealed the supplement as having no significant effects on performance (1). Although it may not affect ones’ performance on the field, it may have an effect on weight loss. The majority of studies conducted have been on this variable and if taking it could assist with weight loss and obesity (2,3,4).


Different populations tested

When you look at the claim of CLA assisting in weight loss, many factors are involved that may make tests results different. One of these factors is the populations that is tested. For example, in the general population you may have different result if both groups were overweight, but one was more active than the other. The factors of age and even ethnic background should also be a consideration when looking at any test results.

Because the populations of different regions are more obese or overweight than others due to eating habits and activity, this should be considered as well. For example, testing subjects that were extremely obese versus those that were just overweight would probably bring about conflicting results.

One study looked specifically at the effects of CLA in weight loss for the Chinese population. China is probably one of the healthier populations concerning obesity. Here the people tested had an average BMI of 24 to 35. One group took the supplement and another took a placebo. The study lasted a total of twelve weeks. Bioelectrical impedance was used to measure body composition. When this is used you must consider the hydration of the subject which this did not mention. This is because if you are not properly hydrated bio electric impedance may not be accurate. The results concluded a very slight weight loss, but an actual increase in bad cholesterol, and a decrease in good cholesterol (8).


Other studies have also revealed a reduction in good cholesterol with no change in bad cholesterol. (3). In a review, studies were looked at which lasted no fewer than six months. Results from the reviews showed no positive effects of cla on body fat loss or other factors from previous studies. (7) Even though it may not have any positive effect on body composition changes, other areas such as insulin sensitivity (5) as well as muscle oxidation or breakdown of muscle proteins may be effected (6) Also, all supplements or medications taken have side effects. Some side effects seen while taking this supplement included constipation, diarrhea, and soft stools. Liver hypertrophy and insulin resistance are also possible side effects (2).

There have been few studies found that looked at the effects of CLA long term. One study was to evaluate the safety of the product and its effect on body composition. Results showed a decrease in body weight and fat for a group taking a placebo, with no changes seen in the group given CLA for 12 months. A decrease in fat mass was seen over 2 years though for those taking the supplement.(3) It must be considered that the reduction in fat mass could be from other variables as well. Spot reduction has also been thought to be possible when taking the supplement. Looking at groups over a period of six months, one taking the supplement and another a placebo, results showed an increase in lean mass and a decrease in body fat of the legs in women (4).


So is cla an effective supplement ? Overall, this supplement has no significant effect on body fat loss or a gain in lean body mass. This includes both the athletic and sedentary population. It may even have a negative effects on cholesterol, increasing bad and decreasing good cholesterol. If you’re active and looking to gain strength and muscle mass, or if you just want to lose fat, CLA is ineffective at both and is not recommended for either performance enhancement or general health.