Conjugated Linoleic Acid (CLA) is found not only in beef fat, but in lamb, buffalo, and ruminants, whole milk, cheese, and butter. Studies show that consumption of raw milk, yogurt, and buttermilk reduces the risk of breast cancer. Women with breast cancer have lower CLA levels in their blood than those without this disease. CLA inhibits the growth of human breast cancer cells, malignant melanoma, colorectal, and lung cancer cells, and animal studies suggest it lowers LDL, resulting in less atherosclerosis and being good for the heart.
Avoiding CLA may be a factor contributing to obesity. "It has been established that eating essential fatty acids helps the body metabolize other fats more efficiently, thereby contributing to weight loss. Yes, eating the right fats help you lose weight. CLA inhibits fat cells from getting fatter. Human studies have shown that consuming moderate amounts of CLA for three months without dieting resulted in as much as a 20 percent loss of body fat. Apparently, CLA affects fat metabolism by interfering with the activity of fat-regulating hormone, leptin, and possibly by increasing insulin sensitivity." (Barbee, p34) It can manage type-2 diabetes by lowering blood sugar levels and reducing body weight. CLA can also stimulate the development of muscle tissue, besides ridding the body of fat, thus body builders take CLA suplements. There is also substantive evidence that CLA is antioxidant.
Unfortunately, good quality CLA is hard to come by in our current food system. Grain-fed beef, Bovine Growth Hormone, skim-, low-fat, and homogenization are to blame.
"Cattle-raising practices over the years have yielded meat that is contaminated with hormones and antibiotics, as well as pesticide residue from the grains fed to the animals. Today's typical beef contains an unnatural, overabundance of the omega-6 fatty acids. Not only that, animals fed hay and grains have a much lower CLA content. Ruminants have digestive tracts that convert the linoleic acid in food they eat into CLA, and when their food is green grass, the CLA content of the meat, or the milk, is many times higher. Grain-fed beef today is deficient not only in CLA but also in the healthy omega 3-fatty acids. Therefore, a search for organically raised beef is well worth the effort, particularly if the animals are allowed to graze." Buffalo meat is also good; they are not fed hormones and eat plenty of grass. (Barbee, p35)
The growth hormone rBST creates higher levels of a specific protein linked to cancer, enhances diabetes in people prone to the disease, and weakens the immune system in humans. It also makes more antibiotics necessary for the cows. Pasteurization destroys many protective health promoting nutrients. Homogenizing milk causes humans to absorb xanthine oxidase, which causes heart disease by damaging the arterial walls (raw milk is best, if it can safely be done). Taking the fat out of milk reduces CLA content, and, obviously, so does drinking soy milk instead of cow milk.