Trans Fat

What is it, and what are its effects on the body?

What is Trans Fat?

Trans fat is made when manufacturers add hydrogen to vegetable oil, a process called hydrogenation. The majority of trans fat is formed when manufacturers turn liquid oils into solid fats like shortening and hard margarine. A small amount of trans fat is found in some animal-based foods, however it is the processed food that seem to be more harmful.

Initially, trans fats were thought to be a healthy alternative to animal fats because they’re unsaturated and come primarily from plant oils. However, in 1990 scientists made a startling discovery: Trans fats appeared to both increase LDL cholesterol and decrease HDL cholesterol. More studies over the years confirmed this.

Trans Fat and Cholesterol

A high LDL cholesterol level in combination with a low HDL cholesterol level significantly increases your risk of heart disease, the leading killer of men and women.

  • Low-density lipoprotein (LDL) - or "bad" cholesterol transports cholesterol throughout your body. LDL cholesterol, when elevated, builds up in the walls of your arteries, making them hard and narrow.
  • High-density lipoprotein (HDL) – or “good” cholesterol picks up excess cholesterol and takes it back to your liver.

Reading food labels

How do you know whether food contains trans fat? Look for the words "partially hydrogenated" vegetable oil. That's another term for trans fat. The word "shortening" is also a clue: Shortening contains some trans fat.

It sounds counterintuitive, but "fully" hydrogenated oil doesn't contain trans fat. Unlike partially hydrogenated oil, the process used to make fully hydrogenated oil doesn't result in trans fatty acids. However, if the label says just "hydrogenated" vegetable oil, that usually means the oil contains trans fat.

Trans Fat Chart