Polyunsaturated fatty acids are a healthy type of fat found naturally in many common foods like seeds, nuts, and fish. There are subcategories of fatty acids, including omega-6 and omega-3. Some of these fats are known as “essential” fatty acids (EFAs) and some are not, however, the body needs all of them to function properly.
Polyunsaturated fatty acids are not only important sources of energy, but they also are found in just about every cell in the body. While there are an estimated 60+ fatty acids throughout blood, plasma, and soft tissues, one type plays a very unique role in the body: CLA.
What is CLA?
Conjugated linoleic acid, or CLA, is a term used to describe an essential fatty acid in the omega-6 category. CLA is unique in that it has a double-bonded chemical structure, which alters it from other forms of its parent fatty acid – linoleic acid (LA). Further, CLA can be broken down into approximately 28 smaller compounds known as isomers. Each isomer has been clinically shown to offer different benefits to human health.
As an omega-6 fatty acid, CLA is essential to the proper function of many body systems, and is vital to overall health. CLA is not made in the body, so it must be taken in through diet.
Linoleic acid is one of the most common omega-6 fatty acids. It is found in many different vegetable oils and widely used in packaged foods, making it one of the most over-consumed fats in the United States. However, conjugated linoleic acid, or CLA, is a compound made in the bellies of ruminant animals including cattle, goats, and sheep, thus the primary sources of naturally-occurring CLA include meat and dairy products.
While CLA is chemically related to LA (linoleic acid), it works in the body very differently. Some isotopes of LA are well-known to cause lipogenesis (fat formation), while CLA is known to inhibit fat formation.
How Does CLA Help With Weight Loss?
CLA was first discovered in 1988 by researchers studying its effects on human health. They found that CLA provided many different benefits, namely in the area of weight management.
Meat from grass-fed animals is lower in fat than yields from grain-fed animals, which means that it is also lower in calories. It is estimated that an average person could cut calories by up to 17,000 a year (equal to about 6 pounds) just by switching from grain-fed to grass-fed animals.1
The consumption of omega-3 EFAs has been clinically shown to promote fat burning.2
One troubling aspect of factory farming involves the large amount of grain fed to food-producing animals. If a ruminant animal was left in its natural environment, it would not consume soy or corn meal feed. Instead, it would graze on grass. The result of grain-fed cattle is a body composition void of a proper omega-6 to omega-3 fatty acid ratio.
A cow that eats a diet of primarily grains will be affected accordingly. Factory farmed food-producing animals make it to dinner tables with an omega-6 to omega-3 fatty acid ratio between 5-to-1 and 13-to-1.
Grass-fed beef animals naturally provide a body composition that includes fatty acids in an ideal 2-1 omega-6 to omega-3 fatty acid ratio.3
An average American consumes approximately 14 to 25 times more omega-6 fatty acids than omega-3 fatty acids, which physicians confirm is associated with inflammation, heart disease, and other major health problems, including unwanted weight gain.4
Health practitioners agree that a balanced ratio of omega-6 to omega-3 fatty acid ratio promotes fat burning.5
Another way CLA promotes weight loss is that is aids in maintaining stable blood sugar levels by lowering the glycemic index load of meals. This means that by consuming CLA, insulin spikes are reduced. As a result, the body may store less fat during food consumption.6
CLAs rare double-bonded chemical structure allows it the unique ability to burn body fat while maintaining overall body mass.7,8
CLA has the exceptional capability to preserve muscle mass, while burning fat.
Numerous studies have confirmed that CLA aids in reducing body fat all over the body while maintaining lean body mass independent of exercise routines.9,10
Additionally, studies suggest that CLA promotes the growth of dense, lean muscle tissue. For this reason, many fitness enthusiasts and bodybuilders use CLA supplements in order to burn fat without losing hard-earned muscle mass.11
CLA is a powerful antioxidant, able to protect soft tissue from cellular damage caused by free radicals.
During exercise, harmful free radical molecules are produced by muscle tissue. However, CLA has been shown to help reduce muscle damage caused by the oxidative process. Studies have suggested its antioxidant properties spare further damage to soft tissues, thus accelerating the healing process and muscle development.12
For athletes concerned about maximizing their training efforts while maintaining delicate muscle, joint, and tendon tissues, CLA may provide therapeutic value.
Other Benefits of CLA
Conjugated linoleic acid is a very powerful substance, able to provide numerous benefits to overall health. Here are just a few more ways CLA supports health and vitality.
Studies have suggested CLA may have beneficial effects on plasma lipids to support a healthy cardiovascular system. Researchers found that high intakes of CLA lowered LDL (“bad”) cholesterol in healthy volunteers to support proper circulatory function.13
As an omega-3 essential fatty acid, CLA has been shown to offer anti-inflammatory properties.14,15 This may be especially helpful for those suffering from consistent joint pain or other inflammatory conditions.
CLA has been shown in clinical studies to influence expression of genes involved in immune cell development and differentiation. In this way, CLA may positively influence the immune response by altering the expression and function of cells involved in immunity.16
As an antioxidant, CLA further promotes the healthy function of the immune system. It may support resistance against common infections like colds or flu.17
Best Food Sources of CLA
CLA can be found in many different, naturally-occurring foods. Some of the best sources of CLA include:
Red meat is one of the best sources of naturally-occurring CLA. However, grain-fed cattle are known to contain only fractional amounts of CLA, compared to grass fed cows. Studies confirm that CLA production is up to four times higher in grass fed cattle, than in non-grass-fed counterparts.18,19
Eggs that have been produced by pasture-raised chickens have been shown to contain more omega-3 fatty acid content than grain-fed varieties. Most of the CLA content can be found in the egg’s yolk.20
Milk, cheese, butter, and other dairy products contain a natural form of CLA. However, it is best to purchase an organic dairy product, as the EFA content is generally higher.21
What is the Daily Recommended Dose?
An average diet includes between 15-174 grams of CLA. A daily dose of between 1.8-7 grams has been used to reduce body fat in obese patients. Greater doses (up to 3.4 grams) have been used, but have not been clinically proved to offer additional benefits.22Many people do not notice visible results of CLA supplementation for weight loss for up to 12 weeks.
Conjugated linoleic acid is an essential nutrient found in some very common foods, including red meat and dairy products. As an omega-6 fatty acid, CLA is involved in maintaining healthy body systems including the circulatory, and immune system. Additionally, studies have confirmed that CLA promotes weight loss independent of changes in physical exercise. Some researchers have found that CLA is able to burn fat faster than regular diet and exercise alone, and further support weight management by aiding in muscle growth and maintenance. Some studies have shown that CLA additionally promotes weight loss by reducing calorie consumption.
Other health benefits of CLA consumption include cardiovascular support, boosted immunity, free radical protection, and anti-inflammatory effects.
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14Riserus U. Supplementation With Conjugated Linoleic Acid Causes Isomer-Dependent Oxidative Stress and Elevated C-Reactive Protein: A Potential Link to Fatty Acid-Induced Insulin Resistance. Circulation. 2002;106(15):1925-1929. doi:10.1161/01.cir.0000033589.15413.48.
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16Calder PC. Long chain fatty acids and gene expression in inflammation and immunity. Curr Opin Clin Nutr Metab Care. 2013 Jul;16(4):425-33. doi: 10.1097/MCO.0b013e3283620616.
17Song HJ, Grant I. Effect of CLA supplementation on immune function in young healthy volunteers. Eur J Clin Nutr. 2005 Apr;59(4):508-17.
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19Nicolosi RJ, Rogers EJ, Kritchevsky D, et al. Dietary conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in hypercholesterolemic hamsters. Artery 1997;22:266-77.
20Lopez-Bote, C. J., R.Sanz Arias, A.I. Rey, A. Castano, B. Isabel, J. Thos (1998). “Effect of free-range feeding on omega-3 fatty acids and alpha-tocopherol content and oxidative stability of eggs.” Animal Feed Science and Technology 72: 33-40.
21Nicolosi RJ, Rogers EJ, Kritchevsky D, et al. Dietary conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in hypercholesterolemic hamsters. Artery 1997;22:266-77.
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