Whenever a popular television health claim makes its way into the media, some skepticism is in order.  A decade-long war on "trans fats", including outright bans in some areas, was not based on science or objective evidence.

Not all trans fats are good, obviously, but you're also more likely to get E. coli from organic food - that doesn't make organic food a bad idea.  We just need better labeling for trans fats, particularly when it comes to dairy and beef products. 

A new review in Advances in Nutrition shows natural trans fats produced by ruminant animals such as dairy and beef cattle are not detrimental to health and show positive health effects. Some studies link those natural trans fats to reduced risk of cardiovascular disease and cancer. It was always the case that consuming natural trans fats produced by ruminant animals has different health effects than consuming industrial trans fats, such as partially hydrogenated vegetable oils used in the preparation of some foods such as some baked goods, but it is hard to separate data from noise.

By definition, ruminant trans fat is naturally-occurring and found in meat and dairy foods. Industrial produced trans fat is a component of partially hydrogenated vegetable oils, which have been associated with cholesterol and coronary heart disease.  The naturally occurring trans fat has a different fatty acid profile than industrial trans fat, which contributes to its different physiological effects. Also, the amount of natural trans fat consumed has been relatively stable and much lower than the amounts consumed from partially hydrogenated oils that have been associated with adverse effects. 

Researchers evaluated an evidence base from epidemiological and clinical studies. Based on their findings, they want to further investigate the health implications of natural ruminant-derived trans fats.

"The body of evidence clearly points to a change needed in how nutrition labels are handled," says Dr. Spencer Proctor, one of the review authors and Director of the Metabolic and Cardiovascular Diseases Laboratory at the University of Alberta in Canada. "Right now, in Canada and U.S. a substantial portion of natural trans fats content is included in the nutrition label trans fats calculation, which is misleading for the consumer. We need a reset in our approach to reflect what the new science is telling us."

 Some European countries omit natural trans fat from nutrition label requirements, like they omit components of vegetables. Another approach may be to have separate listings for industrial trans fats and natural trans fats.   

"With industry, science, regulators and other important groups in this area working together, we can continue to make strides to help the public better understand the health implications of natural ruminant trans fats," says Proctor.