What is the Trans Fat in Food

Food labels are often marked with the highly-desired “No Trans Fat” mark. So, what are trans fats and how they affect our health?

First, we need to know that all the fats and oils in food are glyceryl esters of long-chain carboxylic acids which are called “fatty acids.” So, what makes some of them liquid while other being solid? The difference is whether the long-chain acids are saturated (no double bonds) or unsaturated – containing one or more double bonds.

The natural vegetable oils are glyceryl esters of unsaturated acids and most of the double bonds found in them are in cis configuration. Food industry uses catalytic hydrogenation to convert these into solid cooking fats like margarine which have a longer shelf life. However, in the process of hydrogenation, along with converting to solid oils, some of the double bonds isomerize into trans configuration. Trans acids are edible, however studies have shown that they increase the risk of developing artery diseases as a result of raising the levels of cholesterol and triacylglycerols. The health effects of trans fatty acids are under continuous investigation.