Conjugated Linoleic Acid (CLA) . . .
CLA Reduces Body Fat and Builds Muscle
An extraordinary substance that reduces body fat while increasing lean muscle mass? Yes! This fact is exactly what researchers are reporting about: Conjugated Linoleic Acid (CLA).1 CLA is a polyunsaturated fatty acid with unique and potent antioxidant properties. It is naturally produced in the human body when the essential fatty acid linoleic acid (LA) is metabolized by certain bacteria that live in the intestines.
CLA also enters the human diet through the very animal-based foods thought to be the unhealthiest - primarily red meat and dairy products. Although, to a lesser extent, CLA is also found in poultry and corn oil. One wouldn't think charbroiled beef burgers are a good place to look for a heart-healthy, cancer-fighting molecule - especially one that promises nothing less than the morphological reorganization of our body - yet red meat is one of the primary places where CLA is found.
CLA LOWERS BODY FAT IN ANIMALS
Because CLA is produced naturally in the human body when LA is present, it is not considered an essential nutrient; however, studies have clearly demonstrated that increasing our CLA levels can provide substantial health benefits. CLA reduces body fat and increases lean body mass in various animal species.2-3 The CLA-induced changes in animals have been linked to increased lipolysis (breakdown of fats) in adipocytes (fat cells) and enhanced fatty acid oxidation in both adipocytes and skeletal muscle cells.4 CLA works to break down fats, inhibit fat storage, and mobilize fatty reserves for energy. Although CLA helps to increase muscle mass and reduce body fat, it doesn't reduce overall body weight; rather, CLA changes the body's fat to muscle ratio in favor of more muscle.
CLA LOWERS BODY FAT IN PEOPLE
Now, a recent study in Norway suggests CLA has a similar effect on the human animal.5 This study, conducted by Henrietta Blankson and colleagues at the Scandinavian Clinical Research, followed 60 overweight men and women who were divided into four groups that received varying dosages of CLA, as well as one group who received placebo. Using a process called dual-energy x-ray absorptiometry, the researchers were able to measure each person's body composition. The Scandinavian team found a significant reduction of body fat mass (BFM) within the groups that received 3.4 and 6.8 grams of CLA, although there was no additional effect on BFM with dosages greater than 3.4 grams.5 This study provides compelling evidence that CLA reduces BFM in overweight and moderately obese people. It also provides support for the theory that the beneficial CLA-induced effects observed in different animal species probably hold true for us longevity-seeking primates as well.
THE MANY OTHER HEALTH BENEFITS OF CLA
In addition to reducing body fat and increasing muscle mass, CLA can also have a positive effect on diabetes by improving glucose tolerance.6 CLA also limits food allergy reactions,7 strengthens the immune system,7 and protects against atherosclerosis8 and cancer.9 Animals fed a standard diet supplemented with 1% CLA (of total daily calories) displayed smaller tumors of the prostate compared with control groups, and were also found to have an impressive reduction in lung metastases (spreading of cancer).10 Other studies suggest CLA might reduce the risk of cancer at several sites beside the prostate and lungs, including the breast, skin, and stomach.11-12 However, as with CLA's ability to reorganize the body's fat-to-muscle ratio, its anticancer effects also appear to increase with quantity only up to a certain point - when CLA is 1% of the diet. Above that level, no further protection is offered, although no adverse effects were reported from taking a higher dosage of CLA.12
SOURCES OF CLA
Non-dairy vegetarians (i.e., vegans) are especially vulnerable to having low levels of CLA, because they must rely almost entirely on their own systems to manufacture all the CLA they need, which is inadequate to provide the type of benefits found in the studies. Also, increasing the intake of essential fatty acids doesn't necessarily increase the amount of CLA in the body. Although bacteria that live in the human gut can produce CLA from linoleic acid, according to at least one human study, increasing the levels of linoleic acid in the diet did not produce an increase in blood levels of CLA.13
However, you can raise your blood level of CLA by taking it in supplement form. As a supplement, CLA offers help to overweight individuals who would like to convert excess body fat into muscle mass and also to body builders looking to gain more lean muscle mass. Nearly two-thirds of Americans are overweight, and CLA supplements could prove useful to millions of people who, because of their extra weight, are at a higher risk for developing cardiovascular disease, type 2 diabetes, and certain forms of cancer.
Due to too much fat and too many calories, too much of those foods high in CLA would negate any benefit you would receive from the CLA. This is why CLA supplements are so valuable. Regardless of your dietary preference, now you can easily raise your CLA levels, and gain its protective benefits. You can take charge of your muscle/fat ratio and reshape your body, thereby making a proper entrance into the 21st Century as a living example of evolution's new breed of self-transforming designer beings.
- Pariza M, Park Y, Cook M, Albright K, Liu W. Conjugated linoleic acid (CLA) reduces body fat. FASEB J 1996;10:A3227.
- Park Y, Albright KJ, Liu W, Storkson JM, Cook ME, Pariza MW. Effect of conjugated linoleic acid on body composition in mice. Lipids 1997; 32:853-8.
- Dugan MER, Aalhus JL, Schaefer AL, Kramer JKG. The effect of conjugated linoleic acid on fat to lean repartitioning and feed conversion in pigs. Can J Anim Sci 1997; 77:723-5.
- Park Y, Storkson JM, Albreight KJ, Liu W, Pariza MW. Evidence that the trans-10, cis-12 isomer of conjugated linoleic acid induces body composition changes in mice. Lipids 1999;34:235-41.
- Blankson H, Stakkestad JA, Fagertun H, Thom E, Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat mass in overweight and obese humans. J Nutr 2000; 130:2943-8.
- Houseknecht KL, Vanden Heuvel JP, Moya-Camarena SY, et al. Dietary conjugated linoleic acid normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochem Biophys Res Commun 1998;244:678-82.
- Sugano M, Tsujita A, Yamasaki M, et al. Conjugated linoleic acid modulates tissue levels of chemical mediators and immunoglobulins in rats. Lipids 1998; 33:521-7.
- Lee KN, Kritchevsky D, Pariza MW. Conjugated linoleic acid and atherosclerosis in rabbits. Atherosclerosis 1994 Jul; 108(1):19-25.
- Ip C, Chin SF, Scimeca JA, Pariza MW. Mammary cancer prevention by conjugated dienoic derivative of linoleic acid. Cancer Res 1991 Nov15; 51(22):6118-24.
- Cesano A, Visonneau S, Scimeca JA, Kritchevsky D, Santoli D. Opposite effects of linoleic acid and conjugated linoleic acid on human prostate cancer in SCID mice. Anticancer Res 1998 May-Jun; 18(3A):1429-34.
- Ip C. Review of the effects of trans fatty acids, oleic acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary carcinogenesis in animals. Am J Clin Nutr 1997;66(suppl):1523S-9S. .
- Parodi PW. Cows' milk fat components as potential anticarcinogenic agents. J Nutr 1997;127:1055-0.
- Herbel BK, McGuire MK, McGuire MA, et al. Safflower oil consumption does not increase plasma conjugated linoleic acid concentrations in humans. Am J Clin Nutr 1998; 67:332-7.