Zero Trans Fat? Not So Fast!
Trans fat is created by processing liquid oils to produce a solid fat that is stable at room temperature but can be melted when cooking.
By Philippa Norman MD MPH
Recently I took a stick of Crisco, a jar of Skippy peanut butter, a bottle of olive oil, and assorted other items to a grade school class to talk about good fats and bad fats. Words like "Gross!" and "Ew!" were heard as they realized that the hard white fat of Crisco (partially hydrogenated oil) had been mixed into their favorite peanut butter and was affecting their health. They were interested to learn about good fats, too, when they realized that plenty of tasty foods like olives and guacamole help them to stay healthy. One of the most harmful inventions of food processing is trans-fat, and since the new labeling requirement began January 1, 2006 it is a timely topic.
What are Trans Fats?
Trans fat is created by processing liquid oils to produce a solid fat that is stable at room temperature but can be melted when cooking. Production requires a tank of hydrogen, a closed container to create a vacuum, a chemical catalyst such as nickel, and high temperatures to force hydrogen into available binding sites on the oil molecule. When some of the binding sites are filled with hydrogen and others are not, the oil is referred to as "partially hydrogenated". The hydrogen molecules stick out on opposite sides, hence the word trans. When all available bonds are filled with hydrogen, the fat is referred to as "saturated". Some trans fats occur naturally in dairy products and meat, and as a result of bacterial enzymes in our digestive tract, producing minute amounts of trans fats that we reabsorb into our systems. Coconut and palm oils are naturally occurring saturated fats that have many health benefits and are stable for cooking. Trans fats are not formed by the heating of oil during everyday cooking (though high temperatures do alter fats, reducing their health benefits and increasing free radicals).
Trans Fats in Food
Trans fatty acids are used in foods such as pies, cakes, crackers, cookies, breads and boxed baking mixes. Some cooking fat contains up to 41% trans fats. The coating of some candies contain up to 79% trans fats. Processed peanut butter, meat and cheese spreads. Products such as shortening are 100% partially hydrogenated fat, therefore very high in trans fatty acids. Trans fats increase shelf life - food won't spoil from oxygen exposure because the reactive sites of the fat are already occupied with hydrogen. They prevent fatty foods from separating at room temperature because trans fat molecules stack up tightly and it takes higher temperatures to jostle them apart into a smooth flowing liquid.
What do they do in the body?
Trans fats (known as eleadic and other acids) increase LDL (bad cholesterol) and triglycerides while lowering good cholesterol. They also increase calcification in arteries, especially when magnesium, folate and vitamin B-12 (abundant in fruit and vegetables) are low. This sets the stage for heart disease. Unfortunately, early changes of hardened arteries have been found in teens and grade school children. Trans fats have also been measured in umbilical cords of newborns, but it seems that the placenta and brain have some ability to reduce the amount of trans fats absorbed, though they are still affected. Breast milk, normally very high in fat, can contain substantial amounts of trans fat, depending on the mother's diet. Trans fats contribute to metabolic syndrome, a metabolic train wreck resulting from stress, sedentary lifestyle, high sugar and bad fats. This syndrome consists of insulin resistance (cells don't respond to insulin), hypertension, obesity, and elevated blood lipids.
I have often wondered how companies can label foods as "zero" trans fat when they plainly list "partially hydrogenated oil" as an ingredient. Companies are not required to list trans fats if: the food contains naturally occurring trans fats; the food is classified as a low fat food (even if it contains trans fats); there is less than 500 mg of trans fat per serving. This means companies can say 1 small bag of chips contains 3 servings, so they don't have to reveal that it contains 1.5 grams of trans fat in a bag that is really intended to be one serving.
How do we get rid of trans fats?
The first step is to sharply reduce or eliminate them, while increasing good fats. Studies show that trans fat levels begin to decline within days of reducing consumption. As you eat more good fats, they are used to restore healthy fats in your body. The key is consistency. There is no safe amount of trans fats, so elimination is the goal. Use cold-pressed, organic olive oil, sesame oil or coconut oil to cook. Add flax, borage and other healthful oils to the diet as well. Avocados, olives, walnuts, and other oil-rich foods are delicious sources of healthy fats. Use real butter in moderation, or try butter "substitutes" made from palm oil. To promote heart health, eat lots of fresh fruit and veggies to get magnesium, folate and B12. Get some exercise every day. Though it takes a little more effort, lunches and snacks can be revamped to remove trans fats and substitute good fats. If your kids love chips, use baked chips or chips lightly cooked in unprocessed oil. Use natural nut butters. Try bread with flax seed or sprouted grain breads and tortillas instead of the standard varieties. Bake snacks like muffins and banana bread with walnut oil for flavor and extra omega 3, to eliminate trans fats. The positive changes begin the moment you take the first step!