These days trans fats are generally viewed as a nutritional enemy. But not all trans fats are created equal according to Spencer Proctor, associate professor in the Department of Agricultural, Food & Nutritional Science and founder and director of the U of A’s Metabolic and Cardiovascular Diseases Laboratory. “The problem is when we use the term ‘trans fat’ it encompasses hundreds of different fat molecules,” says Proctor. “Actually trans fats are classed within two different families, and this is where the research component is of value.” One family of trans fats produced during industrial processes (found in foods such as chips and cookies) has been associated with increased risks of heart disease. Foods such as beef and dairy products, on the other hand, contain trans fats from a second category produced naturally through a biohydrogenation reaction caused by bacteria typically present in ruminant animals such as cows and sheep.
“We have a dichotomy in food labelling at the moment: we want to get trans fats out of the food chain, but not all of them because some of them are natural and have very different biological effects on humans and in preclinical models,” Proctor explains.
Proctor’s past research into the effects of the ruminant trans fat vaccenic acid (the most abundant natural trans fat in the food chain) on particular populations revealed that these types of natural trans fats—found in foods such as milk, butter and yogurt—actually have independent health benefits, particularly for people with high cholesterol.
The next step for Proctor’s team was to understand the mechanism of how these natural trans fats are different and what role they play in the body. They found that vaccenic acid acts in two different pathways: the intestine where vaccenic acid is absorbed, and the liver. These two primary organs are involved in regulating lipid deposition and synthesis. In their preclinical models, Proctor’s team believes that they have discovered the mechanism of how vaccenic acid leads to lower blood lipids and to the redistribution of fat.
Proctor is currently in discussions with Canadian and international policy makers and stakeholders about updating the definition of trans fats. In fact, he will speak at and chair a session on natural trans fats at an international lipid conference to be held in Vancouver in May 2012. “We are hoping that expertise from this province can combine with that of international experts to flesh out some of these revised definitions of trans fats,” Proctor says. “It’s really exciting that the work generated at the U of A has led to international recognition and discussion that will positively effect health.”