Translating Trans Fats

Since the low fat diet craze of the 80's and 90's we've come a long way and learned a lot about fat. Namely, there are several different kinds and that not all fat is bad. Fats in foods are made up of four different kinds: polyunsaturated, monounsaturated, saturated and trans. Today we're used to coining fat, based on it's type, into 'good' and 'bad' categories to help us understand this complex nutrient a little easier. Foods like fatty fish species, namely salmon, sardines, trout, and other foods like nuts and seeds, eggs and margarines are some of the sources of 'good' omega (or unsaturated) fats. The 'bad' fats, or those that will raise cholesterol and one's risk for heart disease, are mostly the saturated and trans fats, and found in varying kinds of foods. One of the more infamous fats in recent times has been trans fats. They can be found naturally in some animal based foods, and can also be formed when liquid oils are made into semi-solid fats, like shortening and hard margarine. But just when you thought you were getting a handle on the 'good' and 'bad' for fat, new research is giving us something else to consider. Not all trans fats are 'bad'. That's right, and in fact some may actually be quite the opposite.

What is the difference between the types of trans fats? Industrially produced trans fat would be what we consider the unhealthful kind of trans fats. They're formed when manufacturers use a chemical process that turns liquid oil into a semi-solid form, or partial hydrogenation. They increase the risk of heart disease as these fats can raise ‘bad’ cholesterol and lower ‘good’ cholesterol levels. That being said we should keep our intake of the industrial trans fat as low as possible. So why did these artificial fats come about in the first place? They had advantages for food production. They are more stable and break down less easily under conditions of high temperature heating, which makes them better for frying. Products made with these fats also have a longer shelf life than if made with liquid oils. Today's grocery store culprits for industrial trans fats? Vegetable oil shortening, hard (hydrogenated) margarine, commercially prepared baked goods like toaster strudels, oriental noodles, snack foods like potato, corn chips and crackers, puddings, liquid coffee whiteners and even microwave popcorn. Sometimes liquid vegetable oils and fish oils can also contain small amounts of trans fats, formed during the commercial refinement of these oils. Not to worry, they contain very small amounts (up to 2.5%) and more importantly are important sources of the 'good' essential omega-3 and omega-6 fatty acids.

Natural trans fats on the other hand, are produced by an enzymatic process in the gut of ruminant animals, like lamb, dairy and beef cattle. As a result they are found naturally in their milk and meat products. Perhaps it's something we may see change in the future, but right now natural and trans fats are not distinguished on food packaging. They are however they are both quite different from one another. Natural trans fats we now know are not harmful and may even be health promoting. We're learning that they're associated with strengthening heart health, maintaining a healthy weight and boosting the immune system. It's might be confusing to think that products like yogurt or beef cuts will say ‘trans fat’ on the nutrition facts table and only contain natural (good) trans fats. So even though they're not distinguished, how can you tell the difference? Right now that best way is to remember that natural trans fats are found in natural dairy and beef and lamb products, while industrial trans fats will be more often in processed foods.

For more information on the differences between natural and industrial fat, including comparisons of the amount of trans fats in everyday foods, check out the newly launched website: www.naturaltransfats.ca

As seen in The Telegram June 25, 2012