Conjugated Linoleic Acid is a fatty acid. CLA is a term referring to a mixture of positional and geometric isomers of 18:2n-6. The two double bonds in conjugated linoleic acid are in the carbon chain positions 9 and 11 or 10 and 12, which make it a conjugated diene. Each of the double bonds can be in the cis- or trans- configuration. CLA has unique flexibility properties that affect cell membranes, cholesterol, etc, in a very beneficial way in conditions of obesity, diabetes, Syndrome X, atherosclerosis, cancer, etc.

"Conjugated Linoleic Acid and the Control of Cancer and Obesity," Pariza MW, Park Y, Cook ME, Toxicol Sci, 1999; 52(Suppl.): 107-110.There is evidence that CLA may modulate cellular response to tumor necrosis factor-alpha. CLA may directly affect the process of carcinogenesis; reduce excessive body fat accumulation that indirectly reduces cancer risk, and reduce cachexia (severe wasting) associated with advanced cancer and with certain cancer treatment strategies.  CLA may inhibit the cancer at the initiation, tumor promotion, progression and metastasis phases. CLA may indirectly affect cancer development by reducing body fat and enhancing lean body mass.  CLA appears to reduce the adverse catabolic effects of immune stimulation that include cachexia. 

Conjugated linoleic acid is unique in the sense that concentrations less than or equal to 1% are sufficient for producing significant cancer protection and this effect appears to be independent of other fatty acids. "Review of the Effects of Trans Fatty Acids, Oleic Acid, n-3 Polyunsaturated Fatty Acids, and Conjugated Linoleic Acid on Mammary Carcinogenesis in Animals," Ip, Clement, American Journal of Clinical Nutrition, 1997; 66(Suppl.): 1523S-1529S.

CLA has the therapeutic potential to alter fat body mass and help manage insulin resistance. While studies have shown CLA to be effective preventive therapy for cancer, atherosclerosis and other diseases, the latest findings presented at the 220th national meeting of the American Chemical Society (ACS), August 2000, suggest a role for the compound in both glucose control and weight loss. CLA has been shown to reduce body fat in animals and humans and as such, it has become such a popular supplement among body builders. It is believed that the fat reducing mechanism of CLA involves the rejuvenation of cell membranes in the muscles and connective tissues. This effect on cell membrane function may be an enhancement of insulin sensitivity to help in the overall treatment of Type II diabetes. 

CLA's potential as an adjunctive therapy for the effective management of diabetes was specifically examined at ACS meeting. At Purdue University, Indiana, a study involved 22 confirmed diabetics taking 6.0 grams per day of CLA or placebo oil for eight weeks. Results showed that 64% (versus 40% of placebo) of the subjects who took CLA had improvements in their insulin levels, while 83% (versus 10% of placebo) of them had improved leptin counts. Overall, those on CLA showed a moderate reduction in fasting blood-glucose levels, a decrease in triglyceride levels, improvement in serum leptin levels and free fatty acids. The study's lead author, dietitian Martha Belury, concluded that using a non-pharmacological approach, such as CLA, in combination with pharmaceutical therapy, could help to delay and/or manage diabetes. As well, she believes that it could help to reduce health care costs and the side effects of long-term drug use.

CLA may help dieters to regain more muscle versus fat after they stop dieting is shown in one study carried out by investigators at the University of Wisconsin-Madison, The study consisted of putting 71 obese subjects on a calorie-reduced diet and a moderate exercise program. In addition, 35 of them also took 3 grams of CLA daily (1 gram with each meal), while the other half of the group served as controls by taking a sunflower oil placebo. By the end of the six-month study period, both groups had shed about five pounds. However, while people generally gain about three times more fat than muscle (75% versus 25%) when their weight increases, the CLA group gained back more muscle and less fat, evening out the ratio to 50:50. Lead researcher, Dr. Michael Pariza, director of the university's Food Research Institute, suggests that CLA may work by blocking the function of the key enzymes involved in causing fat cells to expand, thus allowing fat cells to stay small. As such, says Pariza, CLA may prove beneficial as a weight management aid. Moreover, he explains, CLA also reduced fasting blood glucose levels and triglyceride levels. Since glucose levels usually surge after consuming a meal, reducing fasting levels are a good way to even out the highs and lows that diabetics aim to control. This research, however, did not draw any connection between CLA and actual weight loss.

Weight loss without diet or exercise noted. A Norwegian study, whose results were also reported at the American Chemical Society meeting, goes even further by suggesting that CLA may induce fat mass loss and muscle mass gain, independently of diet or exercise. In the study, 60 overweight subjects were randomized into five groups and administered different daily doses of CLA or placebo. While none of the participants were allowed to diet, those taking a CLA supplement experienced a statistically significant reduction in body fat mass, with the most dramatic results being seen among the 3.4 grams and 6.8 grams groups. Increases in lean body mass occurred in all CLA user groups, but was only statistically significant in those taking the highest (6.8 g) dose. However, the researchers report that fat-reducing benefits did level off, and that no additional effect on body fat mass was achieved beyond 3.4 g CLA per day. For genuine health, we still need proper diet with exercise to tone system, move lymphatics, etc.

There are several theories about how CLA may effect its glucose-normalizing, fat-reducing actions in the body. Researchers at Purdue University, for example, suggest from their findings that CLA may work by activating the nuclear hormone receptors located in the liver, peroxisome proliferator-activated receptors (PPARs), which they demonstrated in vivo in liver and adipose tissues in mice and rats. In addition to fueling PPAR activity, CLA acts similarly to ligands of PPAR gamma, called thiazolidinediones, which are potent insulin sensitizers and form the basis of current anti-diabetic drugs in use. In fact, the Purdue research demonstrated that, in rats, a CLA-containing diet was equally effective to a diet containing thiazolidinedione in normalizing impaired glucose. PPARgamma is also expressed in certain types of human cancers, which scientists are now considering as a therapeutic target for the prevention and treatment of cancer. In vitro and in vivo studies have shown that CLA is able to promote apoptosis and inhibit cancer cell proliferation, possibly also by activating PPARgamma in susceptible tumors (Med Hypotheses 2000 Sep; 55(3): 187-188). A Cornell University study shows that CLA reduces breast cancer risk. (J Nutr 1999 Dec; 129(12): 2135-42). Animal experiments similarly exhibited that only 50% of rats feeding on CLA butter developed mammary tumors when administered high doses of carcinogens, compared with 93% of the rats on a control diet. 

CLA's ability to slow the progression of, and reverse, atherosclerosis. An animal study involving cholesterol-fed rabbits showed that dietary levels of CLA amounting to 1% caused atherosclerosis to regress by 30%, and that even at concentrations as low as 0.1%, CLA was able to inhibit atherogenesis. The researchers declared that this was the first study to exemplify the “substantial regression of atherosclerosis being caused by diet alone". (J Am Coll Nutr 2000 Aug; 19(4): 472S-477S).

CLA's ability to reduce body fat may be through increased energy expenditure, other research has pointed out as one of the mechanistic possibilities of CLA. Researchers at the Pennington Biomedical Research Center, Baton Rouge, Louisiana, observed that energy expenditure sped up in CLA-fed mice after just one week of administering the nutritive compound to them. They also reported that the change was sustained for at least six weeks, which would suggest an alteration of metabolism rate. (J Am Coll Nutr 2000 Aug;19 (4):487S-493S). Another study, carried out by investigators at the National institute of Health and Nutrition in Tokyo, Japan, found that a reduction in body fat was mainly the result of CLA-induced apoptosis of preadipocytes (Diabetes 2000 Sep; 49(9): 1534-1542). Meanwhile, a set of four in vitro experiments by researchers at the University of North Carolina-Greensboro led scientists there to conclude that, “CLA may exert its antiobesity effects by inhibiting proliferation, attenuating triglyceride content and/or inducing apoptosis of preadipocytes.”(Lipids 2000 Aug; 35(8): 899-910). 

It would be interesting to see what 2-3 capsules of Bio-CLA per meal would do for those patients who simply do not diet or exercise and who suffer from one or more of the above mentioned maladies.