CLA News

Natural dairy and beef trans fat not harmful – may be beneficial

Red Deer, Alta., Jan. 16, 2008: Not all trans fat is bad – in fact, new research from the CLA Network supports growing evidence that natural trans fat found in dairy and beef products is actually health promoting, not harmful.

In a 16 week animal model feeding trial, University of Alberta researchers observed that increases in trans vaccenic acid (TVA), the main type of natural trans fat found in dairy and beef products, showed no negative effect on blood lipid profiles. Rather, feeding of this natural trans fat was associated with a major lowering of triglyceride levels and a modest lowering of both total and LDL cholesterol levels – all key risk factors for cardiovascular disease and other health threats.

The findings confirmed results from a previous three week trial and now set the stage for potential human clinical trials, says Dr. Spencer Proctor, who led the research along with colleague Dr. Catherine Field. The trials were conducted using a rat species bred to provide a model for metabolic syndrome – a human health condition associated with increased risk of cardiovascular disease and other health threats.

"With the results of these trials, we're very confident we're seeing not only the absence of negative effects but also clearly positive health effects related to the major natural trans fat found in dairy and beef products," says Proctor, a leading blood lipid researcher and director of the university's Metabolic and Cardiovascular Diseases Laboratory.

Among the metabolic syndrome group receiving dietary TVA in the 16 week trial, triglyceride levels were reduced by more than 50 percent, total cholesterol was reduced by approximately 30 percent and LDL cholesterol was reduced by 25 percent.

"The findings support accumulating evidence that we can discriminate between natural trans fats, which appear to be beneficial, versus industrially processed, hydrogenated trans fats that have been shown to be detrimental," says Proctor.

Despite intense public scrutiny of trans fats, there has been little research or dialogue to distinguish between natural ruminant trans fats and artificial industrially processed trans fats, he notes. "Very recent studies have indicated that diets rich in TVA and/or other ruminant fatty acids may be beneficial. However, to our knowledge, our study is the first to demonstrate beneficial dyslipidemic properties solely due to TVA, as opposed to diets that often contain numerous bioactive lipids. This finding is a major achievement for this field."

Trans fat food labeling laws in the U.S. and Canada do not differentiate between natural ruminant-based and industrially processed trans fats. "This has contributed to the public perception, now reinforced by 'trans-fat free' labeling that all trans fats are detrimental to health," say Proctor. "Clearly this perception is not the reality when it comes to natural trans fat found in dairy and beef products."

The CLA Network trials are among the first to specifically examine the health implications of TVA, which is estimated to contribute 80 to 90 percent of ruminant-based trans fat content in the North American diet.

Another key fatty acid found in ruminant-derived fats is conjugated linoleic acid (CLA). Though CLA research is also in early stages, studies to date based largely on animal models indicate that CLA may help fight or prevent diseases such as cancer, heart disease, diabetes and kidney disease. They also indicate CLA may help battle obesity and improve bone density. Because CLA is widely regarded as a beneficial fatty acid, it is not considered a trans fat for nutrition labeling purposes.

Proctor and Field are members of the CLA Network, a network of researchers, food industry representatives, health professionals and communicators working together in support of CLA progress.

The researchers' interest in TVA stems from its role as a "precursor" to CLA. As a precursor, TVA can be converted into CLA once inside the human body, upon interaction with a common human enzyme.

"The TVA findings dramatically strengthen the potential for tapping human health benefits and related market opportunities related to CLA and natural bioactive lipids," says Proctor. "This means good things both for consumers and for the dairy and beef industries."

CLA Network vaccenic acid research is supported by the Alberta Livestock Industry Development Fund (ALIDF), Dairy Farmers of Canada (DFC) and the Beef Information Centre (BIC). More information on the TVA research findings is available in a new article available at www.CLAnetwork.com.