Losing weight can be a difficult and slow process. Dieting, regular exercise and eating at a caloric deficit are the most effective methods of burning away unwanted body fat, but can often become frustrating when roadblocks like food cravings and weight loss plateaus occur.
Many people turn to weight management supplements to help speed up the process of losing weight, but the sheer amount of different supplements available can make it difficult to determine which supplements are safe, healthy and effective.
While some weight management supplements may not live up to their dramatic fat-burning promises, there are a number of natural supplements that, if taken in the correct dosage and combined with regular low impact exercise and a nutritionally-balanced diet, can dramatically increase the rate at which the body is able to break down fat.
CLA, or Conjugated Linoleic Acid, appears to be one such supplement. CLA weight loss supplements have become popular internationally recently due to a series of clinical trials that show promising weight loss results.
In this article, we’ll provide a critical analysis of CLA weight loss supplements and deliver a breakdown of the scientific evidence that supports their use, as well as take a look at any potential health benefits or side effects CLA may offer.
Part of a family of at least 28 isomers of linoleic acid, Conjugated Linoleic Acid is part of a group of chemicals found in the fatty acid linoleic acid. Dairy products and beef are the major and most prominent source of Conjugated Linoleic Acid.
What Is Conjugated Linoleic Acid (CLA)?
CLA, or conjugated linoleic acid, does not refer to just one substance. CLA’s are a family of more than 28 isomers, or structurally similar chemical compounds, of linoleic acid, which is an essential fatty acids. Essential fatty acids are called as such as the body is unable to synthesize them- they can only be found from dietary intake.
A fatty acid you may be familiar with is the omega-3 fatty acid found in supplements such as fish oil, which can help boost energy and reduce the effects of inflammatory diseases.
Conjugated Linoleic acids are altered forms of omega-6 fatty acid that have captured the attention of scientists and medical professionals worldwide for the last few decades due to their apparent health benefits.
CLA first came under the scrutiny of modern medical science in 1979, when a team of researchers discovered that it had the ability to suppress the development of cancer in mice exposed to chemical carcinogens in a clinical trial, the results of which were published in 1987.
Since that first original study, CLA has been shown to have a wide range of health benefits including weight management, muscle mass development, and diabetes management. It was not until the release of a Norwegian study in 2000, however, until the fat burning properties of CLA were discovered.
Published in the Journal of Nutrition, the study performed by the Scandinavian Clinical Research Organization found that CLA reduces body fat mass in overweight and obese individuals.
A normal diet supplies around 15-174 mg of Conjugated Linoleic Acid, every day. Also called CLA, this acid helps to reduce body fat deposits and improves the immune system, allowing it to function brilliantly. In medicine, CLA is used for cancer, “hardening of the arteries” (atherosclerosis), obesity, weight loss caused by chronic disease, bodybuilding, and impeding food allergy reactions.
Health Benefits of CLA?
Scientific studies shown beneficial effects in patients suffering from colon and rectal cancer. Recent research suggests that a regime that is high in CLA reduces the risk of cancer in the colon and rectum in females. Until now, we have only talked about a diet based on this acid, it is not yet sure if Conjugated Linoleic Acid supplements can provide the same health benefits.
Against obesity, CLA seems to be extremely effective in destroying body fat, not body weight. This means it reduces the fat without destroying the muscles and while increasing the metabolic pace. A study conducted and published by the American Journal of Clinical Nutrition discovered that people who used 3.2 grams of CLA a day had a drop in fat mass of about 0.2 pounds a week (that’s about one pound a month) compared to those given the placebo.
There is some evidence showing CLA can prevent breast cancer. Women who undergone menopause and intake Conjugated Linoleic Acid from foods, especially cheese, seem to present lower risks of developing breast cancer.
Another dangerous and fatal disease CLA protects the humans from, is diabetes. Conjugated Linoleic Acids replace the effect of artificial diabetic drugs. After being tested on mice suffering from type II diabetes, it has been proven CLA improves insulin's reaction and reduces the bloodstream's glucose.
Let’s take a look at the various benefits of CLA, and the evidence supporting them:
CLA As A Weight Management Tool
CLA is mainly promoted as a weight loss supplement, but has a number of different benefits that can promote overall health.
Clinical trials and research conducted on both humans and animals have confirmed the veracity of the various health benefit claims of CLA, but offer varying results, so it’s best to take a close look at the clinical evidence for each application.
CLA Can Assist With Weight Loss
The most popular use of CLA is as a weight management tool. The original Scandinavian Clinical Research Organization study sparked a series of clinical trials that all demonstrated that CLA can be used to promote rapid weight loss.
The specific interaction between CLA and the body that promotes weight loss is an increase in basal metabolic rates. The body burns energy harvested from dietary intake to power the body.
If dietary caloric intake exceeds the requirements of the body, the body will store the excess calories as fat. Inversely, a caloric deficit will cause the body to harvest energy from both dietary intake and from the calories in fat deposits, burning away excess body weight.
CLA appears to promote weight loss by causing the body to convert food into energy in a more efficient manner. A meta study performed in 2015 that assessed 70 different clinical trials involving the weight loss effects of CLA determined that CLA has the ability to interact with the lipid metabolism, or the process that causes the development of fat cells.
What this means for individuals seeking to lose weight is that CLA appears to be able to prevent the development of new fat cells, altering the fat-to-muscle ratio of the body.
This mechanism is the cause of the statements made about CLA being able to reduce body fat without the need for any lifestyle changes- although the fat loss process will occur far slower in an individual with a sedentary lifestyle.
There is a huge amount of clinical evidence supporting the use of CLA as a weight management tool. A long-term study conducted by the Scandinavian Clinical Research Organization assessed the effect of CLA supplementation over the course of one year in healthy overweight adult men and women between the ages of 25 and 30.
The results were startling- over the course of the year, the trial group lost an average 9.1% total body fat mass with no significant lifestyle changes.
Another randomized, double-blind, placebo controlled study conducted in 2012 assessed the effect of CLA on participants with high BMI over a 12 week trial.
Compared to the baseline, the participants given CLA supplements experienced a significant loss in total fat mass, fat percentage, waist-to-hip ratio, and subcutaneous fat mass. Another 2007 trial conducted by the University of Wisconsin found that CLA is able to produce modest fat loss in humans over six months.
How Does CLA Promote Fat Loss?
While it’s clear that CLA is definitely able to help promote fat loss, the exact mechanism through which it functions is still a matter of contestation.
Most of the clinical studies concerning the biological process through which CLA boost weight loss have been non-human trials, and provided conflicting results.
One 2011 study performed on mice determined that CLA supplementation is able to cause higher activation rates of perilipin, a protein common in mammals that activates the lipolysis, or fat breakdown process.
This evidence is certainly compelling, but another animal trial conducted in 2005 contradicts the later study completely.
Conducted by the Department of Nutrition and Food Science at the University of País Vasco in Spain, the trial concluded that the body fat-lowering effect of CLA is not due to increased lipolysis, instead suggesting that the fat loss process may be due to a reduction in the rate that fat cells are formed from preadipocytes, or the cells that compose connective tissue.
There is, however, a more detailed study that may shed some light on the exact mechanism through which CLA is able to promote faster fat loss. A meta-study conducted in 2005 that assessed 45 separate CLA trials determined that CLA induced weight loss in humans by both promoting lipogenesis as well as interacting with the mTOR kinase pathway, which is associated with the development of fat tissue.
Regardless of the specific mechanism of action, it’s safe to say that CLA has been conclusively proven to promote faster fat loss in both humans and animals.
How Much CLA Is Enough To Promote Fat Loss?
While we’ve established that CLA is an effective fat loss supplement, it’s important to determine how much CLA is the ideal amount to promote fat loss. The most commonly referenced study regarding sufficient dosage recommends a dose of 500 to 10000 milligrams daily.
This dosage assumes that the CLA supplement in question is at least 70% CLA, but there are many supplements available on the market that offer 80% or more CLA concentration, so this should be taken into account when measuring dosage.
Other studies have shown that dosages up to 3200 milligrams daily can promote rapid weight loss, and dosages of 6.4 grams can promote lean muscle mass growth in obese individuals.
While these trials confirm that doses of over 1000 milligrams can definitely promote faster fat loss, there is currently no conclusive evidence that doses beyond this amount can improve efficiency.
Most commonly available CLA supplements are available in 1000 milligram dosages, making supplementation dosing simple.
CLA may be a proven, effective fat loss tool, but shouldn’t be expected to work as a “miracle pill”. It’s possible that fat loss may occur without any lifestyle changes, but chances are if you’re currently following lifestyle habits that include sedentary habits and a diet rich in fatty or sugary foods, it’s unlikely that CLA will have any effect.
For the best result, CLA should be combined with a shift to healthy nutritional habits and regular low-impact exercise to take advantage of its fat-suppressing properties.
CLA Health Benefits
CLA offers a number of health benefits outside of weight loss applications. Fatty acids have been recognized as positive health supplements for a long time, and CLA supplements are no different. Let’s take a look at some of the other health benefits of CLA:
1. CLA Can Help Reduce Inflammation
Inflammation is the root cause of many diseases such as rheumatoid arthritis, irritable bowel syndrome, leaky gut syndrome, hay fever, and diabetes complications.
CLA has been observed to interfere with inflammatory cell signalling, reducing inflammation and offering beneficial effects for conditions such as metabolic syndrome, colitis, and atherosclerosis.
2. CLA Can Reduce The Symptoms Of Asthma
Airway hyperresponsiveness is one of the most troublesome symptoms of asthma, a condition which causes the airways to become more sensitive to inhaled constrictor agonists, or elements that cause the airways to constrict.
CLA has been demonstrated in a 2010 study to improve airway hyperresponsiveness, reducing the hyper-reactivity of the airway and reducing the frequency of asthmatic events over the course of the 12-week trial.
3. CLA Can Fight Cancer
CLA has even been demonstrated to function as a powerful protective agent against the development of cancer. Breast, colorectal, lung, skin, and stomach cancer rates have all been shown to be minimized by CLA.
There are two specific CLA isomers- t11-CLA and c12-CLA- that have been shown in clinical trials to inhibit the development of tumors in the breast and the stomach.
Interestingly, CLA is able to prevent the development of these forms of cancer at extremely low dietary intake rates, meaning even a small CLA supplement is able offer significant protective qualities.
Is CLA Safe To Use?
CLA certainly has a number of health benefits, but has been shown to have a few side effects in certain situations. In particular, CLA supplementation has been shown to increase insulin sensitivity in diabetes patients.
Insulin sensitivity is extremely important to the body. The body synthesizes insulin in the pancreas to regulate blood sugar levels, and when the body becomes resistant to insulin it can cause blood sugar levels to reach uncontrollable levels, exacerbating type 2 diabetes.
A 2004 study demonstrated that CLA has a negative impact on glucose metabolism and insulin sensitivity in sufferers of type 2 diabetes, meaning CLA supplementation isn’t ideal for individuals that have developed this form of diabetes.
A 2004 study conducted by the Uppsala University in Sweden, however, demonstrated that CLA can have a positive effect on insulin sensitivity in otherwise healthy individuals, so while CLA is not effective as a treatment for diabetes, it is an effective preventative measure.
CLA may also, in extremely large doses, cause a number of other health conditions. Too much CLA can cause fatty liver, which can cause conditions such as metabolic syndrome and diabetes. Other side effects of excessive CLA supplementation include nausea, stomach pain, excessive gas, bloating, and diarrhea.
These symptoms are not present in doses below 3 grams daily, so if you’re choosing to supplement your diet with CLA it’s best to adopt a “less is more” policy. The FDA has classified CLA as GRAS, or generally regarded as safe for use in foods.
Side Effects of CLA?
By accelerating the metabolism, CLA increases the rate of oxidative stress, which destroys the cells and induces them the need for more oxygen. Just like with any other health supplements, you need to check the label twice, before using the product.
When it comes to nursing or pregnant mothers, they need to talk with their doctor before use. It might also cause mild side effects such as stomach upset, diarrhea, nausea, and fatigue.
CLA Rich Foods & Alternatives To CLA Supplements
CLA supplements may be extremely popular, but it’s possible to get all the CLA you need from dietary intake. CLA can be found in the following foods:
- Fresh Beef
- Chicken
- Milk
- Condensed Milk
- Cheddar Cheese
- Eggs
Dairy produce and beef are both rich sources of CLA, but if you’re aiming to increase your CLA intake from dairy products, it’s best to look for grass-fed cow produce.
A 1999 study conducted by the US Dairy Forage Research Center determined that grass-fed beef and milk products are up to 500% richer in CLA than other feed types.
Dietary Sources of Conjugated Linoleic Acid
It is said Kangaroo meat has the highest concentration of CLA. Meat and dairy products from grass-fed animals can produce 300-500% more CLA than those of cattle fed the usual diet of 50% hay and silage, and 50% grain. Eggs and mushrooms are also very rich sources of CLA.
In case you want to get your Conjugated Linoleic Acid from another source, try health supplements. You can find them at pharmacies, over the counter shops and also online.
CLA Health Benefits Review Summary
Overall, CLA is a highly beneficial supplement that, when taken in the correct dose, offer a wide range of health benefits. As with any health supplement, excessive doses can cause negative health effects, but boosting CLA intake by 1-3 mg daily is a safe and effective way to burn fat and protect yourself against a broad spectrum of diseases.
As a weight management too CLA is highly effective but should not be regarded as a “magic bullet”. The fat-inhibiting properties of CLA work best when combined with a regular exercise schedule and balanced, nutritious diet that provides all of the vitamins, minerals and macronutrients the body needs.
Always be sure to consult with a medical professional or health expert before adding any supplement to your diet.
