|
 |
CLA And Cholesterol | | |  | There is compelling evidence that shows that CLA can promote a youthful metabolic function and reduce body fat. The unique way that CLA is able to use its fatty acid properties to protect against disease makes it very important to any anti-aging program. This particular fatty acid has shown strong anti-cancer properties, being particularly effective in inhibiting breast and prostate tumors, as well as colorectal, stomach, and skin cancer, including melanoma. On the whole, scientists found CLA to be more strongly anti-carcinogenic than other fatty acids. What makes CLA especially unique is that even low concentrations significantly inhibit cancer cell growth.
It is important to note however, that while CLA is chemically related to linoleic acid, it appears to have opposite effects in certain important areas. Linoleic acid stimulates fat formation, while CLA inhibits it. Linoleic acid tends to promote tumor growth, while CLA clearly is an excellent inhibitor of tumor growth. Linoleic acid makes cholesterol more susceptible to oxidation, while CLA makes cholesterol more stable.
Although its effects on cholesterol are not as widely known as its effects on weight loss and cancer prevention, CLA is still an important supplement that can be used to improve cholesterol levels. It lowers cholesterol and triglycerides, which in turn, helps to keep arteries clean. A recent study at the University of Wisconsin-Madison found that rabbits supplemented with .5g of CLA each day showed a lower total LDL cholesterol level than rabbits who were not treated with CLA. They also showed a lower LDL to HDL ratio, lower total cholesterol to HDL ratio and lower serum triglycerides. They also had less atherosclerotic plaque. | | | It is not cholesterol per se, but oxidized cholesterol that is harmful to the blood vessels. The oxidizability of cholesterol varies mainly in proportion to the percentage of linoleic acid that it contains; thus the more stable fatty acids, such as CLA, that can be incorporated into cholesterol serve to make it less vulnerable to oxidation. The antioxidant properties of CLA may also play a role in its ability to help keep the blood vessels clean. | | | | An October 2004 study showed that CLA had beneficial effects on cholesterol metabolism, but negative effects on insulin resistance. The excerpts from the study are below: | | | OBJECTIVE:
Conjugated linoleic acid (CLA) is a group of dietary fatty acids with antiobesity and antidiabetic effects in some animals. The trans10cis12 (t10c12) CLA isomer seems to cause these effects, including improved insulin sensitivity. Whether such isomer-specific effects occur in humans is unknown. The aim of this study was to investigate whether t10c12 CLA or a commercial CLA mixture could improve insulin sensitivity, lipid metabolism, or body composition in obese men with signs of the metabolic syndrome.
RESEARCH DESIGN AND METHODS:
In a randomized, double-blind controlled trial, abdominally obese men (n = 60) were treated with 3.4 g/day CLA (isomer mixture), purified t10c12 CLA, or placebo. Euglycemic-hyperinsulinemic clamp, serum hormones, lipids, and anthropometry were assessed before and after 12 weeks of treatment. RESULTS: Baseline metabolic status was similar between groups. Unexpectedly, t10c12 CLA increased insulin resistance (19%; P < 0.01) and glycemia (4%; P < 0.001) and reduced HDL cholesterol (-4%; P < 0.01) compared with placebo, whereas body fat, sagittal abdominal diameter, | | | | and weight decreased versus baseline, but the difference was not significantly different from placebo. The CLA mixture did not change glucose metabolism, body composition, or weight compared with placebo but lowered HDL cholesterol (-2%; P < 0.05). | | | CONCLUSIONS:
These results reveal important isomer-specific metabolic actions of CLA in abdominally obese humans. A CLA-induced insulin resistance has previously been described only in lipodystrophic mice. Considering the use of CLA-supplements among obese individuals, it is important to clarify the clinical consequences of these results, but they also provide physiological insights into the role of specific dietary fatty acids as modulators of insulin resistance in humans. | | |
|
|
|
|
