What is trans fat (trans fat) and why is it harmful to the body?

1. What are trans fats?

Trans fatty acids or trans fats are formed when liquid oils become solid fats.

There are two types of trans fats found in foods: natural trans fats and artificial trans fats. Natural trans fat is produced in the intestines of some animals and the food that these animals produce. For example, milk and meat products can contain small amounts of trans fat.

Artificial trans fats (or trans fatty acids) are produced by an industrial process that adds hydrogen to liquid vegetable oil to make it denser.

2. Why do many foods use artificial trans fats?

The plant produces trans fats through a process called hydrogenation - a process in which vegetable oil is converted to solid fat by adding hydrogen atoms. Hydrogenation increases the shelf life and flavor stability of food. In other words, it makes food more durable.

Trans fats are easy to use, inexpensive to produce, and they also last a long time. Trans fat gives food a good taste and texture. Many restaurants and fast food outlets use trans fats for frying food because oils with trans fats can be used multiple times.

3. Why is trans fat bad?

Trans fat increases "bad cholesterol," aka LDL, and increases your chances of developing heart disease. Trans fat also lowers "good cholesterol" aka HDL. High LDL cholesterol levels combined with low HDL levels increase the risk of heart disease, the leading cause of death in both men and women, and is associated with a high risk of type 2 diabetes.

4. What foods contain trans fat?

The plant-based form of trans fat, known as partially hydrogenated oil, is found in a variety of food products, such as:

Baked foods. Most cakes, pastries, pies, and biscuits contain shortenings, which are usually made from partially hydrogenated vegetable oil. Ready-to-eat frostings are also a source of trans fats.
Snack. Potato chips, corn and tortillas generally contain trans fat. While popcorn can be a healthy snack, many types of packaged popcorn use trans fats for cooking or flavoring the popcorn.
Fried food. Foods that require technique deep frying - French fries, donuts and fried chicken - can contain trans fats which are used during the cooking process.
Cooled dough. Products such as canned biscuits and cinnamon rolls often contain trans fats, as well as frozen pizza rolls.
Creamers and margarine. Coffee creamer and margarine can also contain partially hydrogenated vegetable oils.

Small amounts of trans fat often occur naturally in several meat and dairy products, including beef, lamb, and butterfat. There hasn't been enough research to determine whether these natural trans fats have the same adverse effects as factory-processed trans fats.

5. How to avoid trans fats?

If you want to reduce your intake of trans fat, you must:

Eat a diet that increases in fruit, vegetables, whole grains, low-fat dairy products, poultry, fish and nuts. And, limit your consumption of red meat, foods and drinks that contain lots of sugar.
Use natural, non-hydrogenated vegetable oils such as canola, safflower, sunflower and olive oil.
Choose processed foods made from non-hydrogenated oils over non-hydrogenated or partially hydrogenated vegetable oils or saturated fats.
Use soft margarine as a substitute for butter, and choose soft margarine (liquid or tub) over a tougher stick form. Look for "0 g trans fat" on the nutritional information label and no hydrogenated oil on the list of ingredients.
Donuts, cookies, crackers, muffins, pies and cakes are examples of foods that can contain trans fat. Limit consumption of these foods.

Limit consumption of fried and grilled foods with shortening or partially hydrogenated vegetable oils. Not only are these foods very rich in fat, they are most likely trans fats.

Take some time to read food labels, and choose healthier options. This habit can protect your health and your money in the long run.