What’s so bad about Trans Fats?

Since 1993, food labels have included information on saturated fat and cholesterol.  In 2006, the U.S. Food and Drug Administration also began requiring information on trans fat.  What are trans fats and why is an understanding of it important to our health?

What is trans fat?  Trans fat is produced when manufacturers add hydrogen to vegetable oil, a process called hydrogenation.  This process turns liquid oils into solid fats like shortening and hard margarine.  A small amount of trans fat is found naturally, primarily in dairy products, some meat, and other animal-based foods.

Why have trans fats been used in food preparation?  Companies like using trans fats in their foods because they give foods a desirable taste and increase their shelf life.  Many restaurants and fast-food outlets use trans fats to deep-fry foods because oils with trans fats can be used many times in commercial fryers.

What's wrong with eating trans fat?  Many doctors consider trans fat to be more harmful to our health than saturated fat or cholesterol.  Most people are aware that consumption of saturated fat and dietary cholesterol raises low-density lipoprotein (LDL), or "bad" cholesterol levels.  An elevated LDL level in the bloodstream increases the risk of developing coronary heart disease (CHD).  Like saturated fats, trans fats raise LDL "bad" cholesterol, but they also lower HDL "good" cholesterol.  This further increases the risk of developing "hardening of the arteries" (arteriosclerosis) and heart disease.

What foods contain trans fats?  Trans fat can be found in vegetable shortenings, some stick margarines, and other foods made with or fried in partially hydrogenated oils. Foods with the highest amount of trans fat include:

• cookies, crackers, cakes, muffins, pie crusts, pizza dough, and breads such as hamburger buns
  
  
• pre-mixed cake mixes, pancake mixes, and chocolate drink mixes
  
  
• foods, including donuts, French fries, chicken nuggets, and hard taco shells
  
  
• snack foods, including chips, candy, and packaged or microwave popcorn
  
  
• frozen dinners

Is any amount of trans fat safe to eat?  The American Heart Association recommends limiting the amount of trans fats you eat to less than 1 percent of your total daily calories.  With a 2,000 calorie a day diet, no more than 2 grams, or about 20 calories should come from trans fat.

How can I limit my intake of trans fats?  Here are some practical tips you can use every day to keep your consumption of saturated fat, trans fat, and cholesterol low while consuming a nutritionally adequate diet.

• Check the Nutrition Facts panel to compare foods and choose foods lower in saturated fat, trans fat, and cholesterol.
  
  
• Choose alternative fats. Replace saturated and trans fats in your diet with monounsaturated and polyunsaturated fats.  These fats do not raise LDL cholesterol levels and have health benefits when eaten in moderation.  Sources of monounsaturated fats include olive and canola oils.  Sources of polyunsaturated fats include soybean oil, corn oil, sunflower oil and foods like nuts and fish.
  
  
• Choose vegetable oils (except coconut and palm kernel oils) and soft margarines (liquid, tub, or spray) more often because the amounts of saturated fat, trans fat, and cholesterol are lower than the amounts in solid shortenings, hard margarines, and animal fats, including butter.
  
  
• Eat more fish.  Most fish are lower in saturated fat than meat.  Some fish, such as mackerel, sardines, and salmon, contain omega-3 fatty acids, which are being studied to determine if they offer protection against heart disease.
  
  
• Choose lean meats, such as poultry without the skin, lean beef and pork, with visible fat trimmed.