How trans fat harm you

Trans fat raises the risk of heart attacks and stroke. Trans fat also has a bad effect on cholesterol levels.

There are two main types of cholesterol:

• Low-density lipoprotein (LDL) cholesterol. LDL cholesterol is known as "bad" cholesterol. It can build up in the walls of arteries and make them hard and narrow.
• High-density lipoprotein (HDL) cholesterol. HDL cholesterol is known as "good" cholesterol. It picks up extra cholesterol and takes it back to the liver. The liver breaks down cholesterol and passes it out of the body.

Trans fat raises LDL cholesterol and lowers HDL cholesterol. This can make a heart attack or stroke more likely.