CLA
( Conjugated Linoleic Acid )
The following are some excerpts from a quick on-line search for conjugated linoleic acid 
on Google. Do your own research and read about the wonderful benefits of CLA 
found mostly in  pasture raised grazing animals. It is especially interesting to read about CLA 
research done on wild ruminants like deer. (venison)
Also try searching for conjugated linoleic acid under Google Images. Below are some interesting links.
http://www.mercola.com/beef/cla.htmhttp://www.usu.edu/trdhiman/cladhiman.htm
Purdue research on caveman diets.
http://news.uns.purdue.edu/html4ever/020204.Watkins.paleo.html

CLA information at eat wild.com (a source for pasture based farming information)
http://www.eatwild.com/cla.html
Tamarack Lamb & Wool is listed alphabetically at the bottom of the MN page.
http://www.eatwild.com/products/minnesota.html
It is kind of funny how man keeps "rediscovering" what 
 nature already knows!

The discovery of conjugated linoleic acid (CLA) caused a scientific sensation some years ago.

This fatty acid found in red meat and cheese showed strong anti-cancer properties, was particularly effective in inhibiting breast and prostate tumors, as well as colorectal, stomach, and skin cancer, including melanoma.

Scientists found CLA to be more strongly anti-carcinogenic than other fatty acids. What made CLA especially unique is that even low concentrations significantly inhibited cancer cell growth.CLA supplementation was also shown to improve the lean mass to body fat ratio, decreasing fat deposition, especially on the abdomen, and enhancing muscle growth. To achieve this, CLA reduces body fat is by enhancing insulin sensitivity so that fatty acids and glucose can pass through muscle cell membranes and away from fat tissue. This results in an improved muscle to fat ratio. Compelling evidence indicates that CLA can promote youthful metabolic function and reduce body fat. The unique mechanisms by which this fatty acid protects against disease makes it an important addition to any supplement program.

Compared to the previous generations, Americans are deficient in CLA, because changes in cattle-feeding practices have decreased CLA content in meat and milk. For optimal CLA production, cows (and sheep ) need to graze on grass rather than be artificially fattened in feed lots. The meat of grass-fed cows contains up to four times as much CLA. Today's dairy products have only about one third of the CLA content they used to have before 1960.

Raising grazing animals on pasture is the key!

I find it amazing how, after years of research, and who knows how many millions (billions ?) of dollars spent trying to improve meat and milk production by raising grazing animals in feed lots, we now are discovering that its all wrong!!!Grazing animals have been supplying us with very healthy food ( red meat & milk ) for thousands of years, and it is only recently that man has decided to improve on nature by removing the grazing animals from the pasture, and corralling them in a feed lot.

At Tamarack, we discovered very early that our sheep were much healthier out on pasture than when we had them in a barn, especially in winter. It is only natural when you think about it. They have been living outdoors for thousands of years. Pasture is what they need. It is the lowest stress environment for them, and we are now just discovering how important a role stress plays in human lives. Think about it!

One big reason for the current obesity epidemic in America could be CLA deficiency.

Several animal studies showed that adding CLA to the diet resulted in leaner, more muscular bodies. One 1996 study, for instance, showed as much as 58% lower body fat in CLA-supplemented mice.CLA is the component of red meat that has been shown to prevent cancer. The FDA has published research attesting to the anti-cancer properties of CLA. CLA is used by body builders to drive glucose into muscle cells to produce anabolic effects. Dieters use this same sugar burning mechanism to prevent serum glucose from turning into body fat. The new CLA oil is about 50% stronger in the cis-9, trans- 11, isomer (which scientists consider the most active isomer).CLA also has antioxidant properties, and has been shown to prevent muscle wasting (an anti-catabolic effect).CLA is chemically related to linoleic acid, but appears to have opposite effects in certain important areas. For instance, linoleic acid stimulates fat formation (lipogenesis) in adipose tissue, while CLA inhibits fat formation; linoleic acid tends to promote tumor growth, while CLA is an excellent inhibitor of tumor growth; linoleic acid makes cholesterol more susceptible to oxidation, while CLA makes cholesterol more stable.One of the greatest problems with the Western diet during the last fifty years has been excessive consumption of linoleic acid, due to the introduction of margarine, seed oils such as corn oil and safflower oil, and the modern artificial feeding methods (the cattle and lamb feed lots, where they have no access to pasture grasses) of cattle that have raised the linoleic acid content of meat. At the same time, the consumption of beneficial fatty acids such as omega-3 fats (fish, flax, perilla) and CLA has gone down. Because of the enormous impact that fatty acids have on our physiology, an excess of linoleic acid combined with a deficiency of CLA could have far-reaching effects on health and longevity.

Carol Steinhart: One of the more interesting new items in health-food stores is CLA, conjugated linoleic acid. Its diverse effects suggest that it is involved in one or more of the most fundamental aspects of cell structure and chemistry. For example, it channels energy use toward buildup of lean body mass and away from deposition of fat; it mitigates some undesirable aspects of the immune response, such as anorexia and the breakdown of protein; and it protects laboratory animals against a variety of experimental cancers (see citations in references at end of article). It is likely to enjoy considerable attention from the media, as well as practical applications in agriculture and the food industry, so here is a bit of the chemistry and biology "behind the news"CLA is a group of positional and geometric isomers of octadecadienoic (linoleic) acid having a conjugated double-bond system starting at carbon 9, 10, or 11. All configurations cis-trans, trans-cis, cis-cis, and trans-transare possible in each of the three positional systems. The structures below depict the c-9,t-11 and t-10,c-12 isomers, which are the most abundant ones in foods. Conventional linoleic acid, an essential dietary fatty acid found mainly in plant oils, is also illustrated, showing its double bonds in the cis configuration at carbons 9 and 12.The conjugated diene structure is not usual in fatty acids, although the existence of CLA has been known for many years.

Investigators in the 1950s learned that microorganisms in the rumen of ruminant animals such as cows and sheep produce CLA from polyunsaturated fat.

Then the c-9,t-11 isomer was shown to be the first intermediate product in the biohydrogenation of linoleic acid by the anaerobic rumen bacterium Butyrivibrio fibrisolvens. The reaction is catalyzed by the enzyme linoleate isomerase, which converts the cis-12 bond of free linoleic acid to a trans-11 bond. The normal intestinal flora of rats can also convert linoleic acid to the c-9,t-11 isomer, but the reaction does not take place in animals lacking the requisite bacteria. One reason why ruminants produce more c-9,t-11-CLA than nonruminants is that hydrolysis of fat within the rumen provides more unesterified linoleic acid than is available to bacteria in nonruminants.Foods from plants, too, contain CLA, but the distribution of isomers differs sharply from that in animal foods, where the microbial product predominates. In particular, there is proportionately much less c-9,t-11, which appears to be the biologically active form. A mixture of conjugated linoleic acid isomers is also produced during food processing, by thermal isomerization and by some industrial processes for partial hydrogenation. Energetically, formation of a trans bond is favored (hence the notorious trans monounsaturated fatty acids in margarine); but in contrast to the isomerase-catalyzed reaction, it may form between either pair of carbons in the conjugated system. Because no current analytic technique can separate the c-9,t-11 and t-9,c-11 isomers, differential identification of these two in foods is not possible. Plant foods probably contain both; animal foods too may contain small amounts of t-9,c-11-CLA in addition to the microbial product. It is interesting that oxidative reactions have no important effect on CLA during food processing and storage. Nor does conventional processing alter the total CLA content of foods, although concentrations of c-9,t-11- (t-9,c-11-) CLA may be lower after processing.So CLA is largely a product of microbial metabolism in the digestive tract primarily of ruminants, but to a lesser extent in other mammals and some birds. Whether eaten in the diet or synthesized in the digestive tract, it is absorbed from the gut and distributed throughout the body, where the c-9,t-11 (and perhaps the t-9,c-11) isomer is incorporated into blood lipids, cell membranes, and fat tissue.

In addition, mammals secrete relatively large amounts into their milk. Little is known about the further metabolism of CLA in animals, but what evidence there is suggests that the slow elongation of the carbon chain and further desaturation of carbon-carbon bonds it undergoes in some tissues leaves the original conjugated diene structure intact.The exciting part of the CLA story began serendipitously, as such stories frequently do. In the late 1970s, at the University of Wisconsin's Food Research Institute, Michael Pariza was investigating mutagens in cooked beef. To his surprise, he discovered a fraction from grilled and raw beef that consistently modulated mutagenesis in the Ames (Salmonella) test and frequently showed marked antimutagenic activity. The active material was identified as CLA, and subsequent work by Pariza and his associates and others began to reveal its astonishing range of biological effects.CLA is an in vitro antioxidant, and in cells it protects membranes from oxidative attack. In relation to other important dietary antioxidants, it quenches singlet oxygen less effectively than b-carotene but more effectively than a-tocopherol. It appears to act as a chain-breaking antioxidant by trapping chain-propagating free radicals. Pariza postulates that its antioxidant activity arises from steric hindrance of reactions involving the carbon-centered radical.Because many antimutagens and antioxidants are also anticarcinogens, Pariza began to study the effects of CLA in animal models of cancer. In mice, CLA inhibited cancers of the skin and forestomach caused by exposure to carcinogens. In rats, it inhibited mammary and colon cancer. Researchers at Washington State University found that physiologic concentrations of CLA kill or inhibit cultured cells of human malignant melanoma, colorectal cancer, and breast cancer. These effects may be partly attributable to CLA's antioxidant activity. However, CLA also modulates the activity of cytochromes P450 and suppresses the activity of ornithine decarboxylase and protein kinase C, enzymes involved in carcinogenesis. It may suppress protein and nucleic acid synthesis in cancer cells, as well.Rabbits and hamsters are frequently used to study diet-induced atherosclerosis. When rabbits and hamsters were fed cholesterol-supplemented diets, animals who also received CLA had lower levels of total and LDL ("bad") cholesterol in their blood and developed less atherosclerosis in their aortas.The tissue breakdown (catabolism) that normally follows stimulation of the immune system partitions energy away from important processes such as growth. Although the effects of CLA on the immune system and inflammatory response resemble those of fish oil and may be mediated by similar mechanisms, Pariza and his colleague Mark Cook found that CLA is better able than fish oil to prevent anorexia and growth suppression in mice injected with endotoxin. Similar favorable actions of CLA on the immune system were seen in rats and chickens. Because the immune system is under constant assault from "outside forces" such as bacterial endotoxin, one consequence of CLA's energy-partitioning effects might be to promote growth. In fact, Pariza and his co-workers did observe that rat pups whose mothers' diet was supplemented with CLA during gestation and lactation gained weight faster than pups whose mothers were fed only normal chow. Continued supplementation with CLA after weaning maintained the growth advantage of these pups, who utilized their feed more efficiently, gaining more weight and more lean body mass per unit of feed eaten. Since CLA is found in milk, Pariza postulates that it is a growth factor for rats and possibly for other mammals as well. These experimental results suggest uses for CLA in animal agriculture.

What foods contain the most CLA? Lamb. Beef. Surprisingly, turkey (but not chicken).

Above all, dairy products (not fat-free ones, because they wouldn't contain much conjugated fatty acid). The CLA content of these foods ranges from 2.5 to 11.0 mg per gram of fat, and 75% or more is c-9,t-11 (t-9,c-11). Common plant oils, in contrast, contain only 0.1-0.7 mg/g of CLA, of which less than half is c-9,t-11 (t-11,c-9). Seafood is a poor source. Unfortunately, a CLA-rich diet is a high-fat diet. However, large-scale production of CLA utilizing the action of the bacterial isomerase on linoleic acid may be feasible, permitting future fortification of foods, should this appear desirable, and other commercial uses. Pariza, who enjoys a grilled cheeseburger as much as anyone, grins as he reflects on the negative image of animal fats in contrast to the positive image of plant oils. He points out that conventional linoleic acid, the major component of corn oil, is so far the only fatty acid proven to enhance cancer in experimental animals. So it is ironic that in its conjugated form, which is found mainly in animal fats and foods of animal origin, it is the most powerful naturally occurring fatty acid with proven ability to protect against cancer! In fact, it is the only known antioxidant/anticarcinogen primarily associated with animal foods. Moreover, amounts close to those in a normal mixed human diet are effective, not only in cancer protection but also in all the other biological activities of this compound. This well illustrates the fallacy of the "good food, bad food" approach to diet and nutrition. CLA is no panacea. But it is very interesting, and you will hear more about it.