Definition Trans fats are formed by the partial hydrogenation of vegetable oil. This process is used to make vegetable oil more solid. An example of this is cooking and more solid margarine.
What food source is the nutrient found in? Trans fats are found naturally in some meats and dairy products. Bigger sources of trans fats are foods made with or cooked in hydrogenated vegetable oil. These include crackers and fried snack foods such as potato chips and corn chips. Trans fats are found in baked goods such as biscuits, cakes, and pastries. Margarine and hydrogenated vegetable shortening also contain trans fats.
If the ingredients include "partially hydrogenated vegetable oil," then the food has trans fats in it. Ingredients will be listed on the package. Trans fats are not listed on the Nutrition Facts Panel.
How does the nutrient affect the body? Hydrogenated fat does not go stale as quickly as regular unsaturated fat. Foods made with it can stay on supermarket shelves longer. It gives commercially prepared foods a taste and texture similar to regular fat. It is less expensive than butter and more stable than unsaturated fat. Hydrogenated vegetable oil is often chosen for deep-frying and is used by many restaurants.
Information In the early 1900s cottonseed oil was hydrogenated to make vegetable shortening, as a replacement for lard. Margarine was discovered in the 1930s. It gained popularity as people became aware of the relationship between saturated fat and heart disease.
Saturated fats come from animal products and raises cholesterol. Unsaturated fats do not. The effect of trans fat is less clear. Some studies indicate that it raises cholesterol levels. This increases the risk for heart disease. There is also evidence that trans fats may cause cancer. Research in both areas is ongoing.
If you are watching your cholesterol, choose soft tub margarines and use them in moderation. In general, the softer the margarine, the less trans fat it contains. Margarines made without trans fat are now available.
The Heart Foundation encourages cooking and baking with unsaturated oils, that are not hydrogenated, whenever possible. Good examples include nut oils, olive and corn oils. Limiting total fat and saturated fat in the daily diet is also recommended. This will help to reduce the amount of trans fat consumed.
Author: Susan Harrow Rago, RD, MS Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request