"Trans fat" is a name that does not have a good reputation. Trans fatty acids rarely occur in nature, and the trans fats in food are usually present as a by product of industrial processes, such as the hydrogenation of vegetable oil. Although these contaminating trans fats are edible, research has shown that they are detrimental to cardiovascular health. It is generally believed that there is no safe or desirable level for trans fat consumption, and this has prompted regulatory bodies and industry to act toward reducing the amount of trans fats in food products.
In Australia, unlike some other countries, we do not have laws regulating allowable trans fat levels in food, but in 2007 our government made a commitment to actively work to reduce the levels of trans fats in fast food. As a result, many brands have altered their processes or ingredients in an effort to become trans-fat free.
Trans fats are most commonly found in processed and fast food, but there are some trans fats that are found in nature. Trans-11 vaccenic acid is probably the most common and best known of these, and it occurs in the dairy products and fat of ruminant animals, and in human breast milk.
Natural and artificially produced trans fats are thought to have different properties. This has recently been demonstrated by a Canadian research group that has showed huge potential for vaccenic acid in the treatment of obesity and metabolic syndrome in an animal model. The researchers studied obese rats who were displaying symptoms of metabolic syndrome, which in humans is a state characterised by cardiovascular disease and insulin resistance.
The rats were split into two groups. A control group was fed a diet containing dairy-derived fat, whereas the experimental group received the control diet supplemented with 1% vaccenic acid. At the conclusion of the trial, the differences between the two groups were remarkable.
Compared to the control, the experimental group showed a 6% decrease in overall body fat, including a 17% decrease in mesenteric fat, a type of fat distribution which is associated with metabolic syndrome. On top of this, the average size of each fat cell was down 44%. These rats also showed a 7% increase in basal metabolic rate and a whopping 59% increase in insulin sensitivity, along with a 34% decrease in scores that measure the extent of fatty liver disease.
These results demonstrate huge potential for vaccenic acid supplementation to play a role not only in the treatment of this unfortunately too-common disease, but also in weight loss, boosting the metabolism, and in overall health.
At present, the research on this fatty acid is very preliminary, and in some cases conflicting. A lot of work will need to be done before vaccenic acid could even be considered a as cure for obesity and cardiovascular disease, rather than a cause. Still, this research is very promising, and there is every chance we could be looking at the next omega-3.
Jacome-Sosa MM, Borthwick F, Mangat R, Uwiera R, Reaney MJ, Shen J, Quiroga AD, Jacobs RL, Lehner R, Proctor SD. Diets enriched in trans-11 vaccenic acid alleviate ectopic lipid accumulation in a rat model of NAFLD and metabolic syndrome. J Nutr Biochem. 2014 Mar 18.