|Advanced Health & Life Extension||
CLA Conjugated Linoleic Acid
What is CLA or Conjugated Linoleic Acid
Conjugated linoleic acid (CLA) is a naturally-occurring polyunsaturated fatty acid. It is a group of isomers of linoleic acid, meaning that it is chemically identical but has the atoms arranged in a different patern than ordinary linoleic acid. Linoleic acid is one of the essential fatty acids. The human body is unable to manufacture Linoleic Acid or CLA, so it must be obtained from dietary sources. Foods highest in CLA include dairy products and meat from ruminant animals, such as beef, lamb, and veal.
Benefits of CLA
CLA has been the subject of a variety of research studies in the past several years and findings suggest that some of the benefits of CLA include the following:
CLA and Heart Health
In one study, researchers investigated the cholesterol-lowering effects of CLA on hamsters. Compared to controls, the CLA-treated animals collectively experienced a significant reduction in levels of plasma total cholesterol, LDL cholesterol, and triglycerides. Atherosclerosis took much longer to develop in the aortas of the CLA-treated groups than in the controls.
In another study, researchers fed rabbits a standardized diet. Half of the rabbits were given CLA (0.5 g CLA/rabbit per day) for a period of 12 weeks. As compared to controls, the researchers found that total cholesterol, LDL cholesterol and triglycerides were markedly lower in the CLA-fed group. In addition, the LDL cholesterol-to-HDL cholesterol ratio and total cholesterol to HDL cholesterol ratio were significantly improved in CLA-fed rabbits. Again, the aortas of CLA-fed rabbits showed less atherosclerosis than in controls.
CLA Anti-Cancer Effects on Breast Cancer, Colon Cancer and Prostate Cancer
In vivo animal and human cells indicate that CLA may protect against prostate, mammary and colon cancer. In one impressive study researchers induced experimental mammary cancer in rats. They then fed the animals either high CLA butter fat or a free fatty acid mixture of CLA isomers (typical of that found in supplemental CLA) during the time of pubescent mammary gland development. Only 53% of the animals given CLA, both in the form of butter and free fatty acids, developed mammary tumors compared to 93% of controls!
The researchers concluded that CLA could be beneficial in reducing the risk of breast cancer. According to Dale Bauman, one of the lead authors of this study, 'Most dietary substances exhibiting anti-carcinogenic activity are of plant origin and are only present at trace levels. However, CLA is found almost exclusively in animal products and is among the most potent of all naturally-occurring anti-carcinogens.' In another study of animals with experimental breast cancer, the spread of the tumors was inhibited in proportion with increasing concentrations of dietary CLA. CLA was nearly as effective as indomethacin, a pharmaceutical suppressor of tumor growth and metastasis.
Conjugated linoleic acid has been shown to inhibit ACF, a biomarker of colon cancer, in rats.
In another study involving prostate cancer, immunodeficient mice were injected with human prostate cancer cells. Mice fed a CLA enhanced diet had smaller tumors and a reduction in metastases.
CLA for Weight Loss and Muscle Building
CLA has been shown to decrease body fat content by inhibiting fat storage and reducing the amount of fat deposited in the body. In one study, researchers found that pigs fed CLA showed a reduction in fat deposits of 31%, and an increase in lean tissue formation of 25% over an eight-week period.
Using human subjects, a double-blind, randomized, placebo-controlled study, published in the December 2000 issue of the Journal of Nutrition found that CLA reduces fat and preserves muscle tissue. An average reduction of six pounds of body fat was found in the group that took CLA, compared to a placebo group. The study found that approximately 3.4 grams of CLA per day is the level needed to obtain the beneficial effects of CLA on body fat.
A research study done at the University of Wisconsin-Madison, reported in August 2000 to the American Chemical Society did not find weight loss in overweight people from use of CLA supplements. However, they did find that when the dieters stopped dieting, and gained back weight, those taking CLA "were more likely to gain muscle and not fat.''
In another study involving human subjects, those taking CLA experienced a small weight loss, about 3.5 pounds without altering their calorie intake.
Researchers also found that higher levels of CLA in the bloodstream were associated with lower levels of leptin, a hormone that is believed to control the levels of fat in the body. In the placebo group, leptin levels rose slightly. Studies have indicated that high leptin levels may have a part to play in obesity.
CLA and Diabetes
CLA is functionally similar to certain insulin sensitizers. This fact offers the possibility that CLA could be helpful in treating or preventing diabetes. Researchers discovered that CLA normalized impaired Glucose function and reduced hyperinsulinemia in diabetic rats. In a separate study conducted at Purdue University, CLA was found to improve insulin levels in about two-thirds of diabetic patients, and moderately reduced the blood glucose level and triglyceride levels. Diabetics who suplemented their diet with CLA had lower body mass and lower blood sugar levels when compared to the control group.
Since the trend is to consume less of the natural sources of CLA, meat and dairy fat, taking supplements may make sense.
Studies suggest that taking 3 to 4 grams of CLA per day can improve the muscle-to-fat ratio. By contributing to a loss of body fat, particularly abdominal fat, while increasing lean tissue formation, the result can be a leaner, and thus, healthier body.
It should be emphasized again that taking CLA alone will not be an effective weight loss remedy for most individuals. When combined with a good diet and exercise plan, it will enhance the effects of your other efforts and make it easier to keep the weight off.
CLA Side Effects
So far no adverse effects or drug interactions have been reported for CLA.
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