Food producers understand that solid fats increase shelf stability and maintain the flavor in many baked and processed foods. Therefore, in the early 1900s, they began changing polyunsaturated liquid oils such as corn or soybean oil into solid fats by adding hydrogen atoms. This process is called hydrogenation and results in a product called "trans fats." The Crisco Co. first commercialized this process in 1911.
(Some trans fats are found naturally in animal products such as beef and lamb, but most are created through the above-described chemical process.)
In the past few years, the topic of trans fats has become hot. Consumer groups have been pushing to remove trans fats from products that commonly use them, such as margarines, baked goods (cakes, pies, breads, cookies, crackers), processed snack foods (potato chips, corn chips, popcorn) and fast foods (commercially fried potatoes, onion rings, chicken). And beginning in January 2006, the Food and Drug Administration began regulating trans fat labeling on food packages, making it easier for consumers to know how much they are consuming.
The recommended intake of this fat is zero. In fact, researchers are still unsure of what a safe intake level is. According to the American Heart Association, trans fats increase our risk of coronary artery disease by raising "bad" low-density lipoprotein cholesterol and lowering "good" high-density lipoprotein cholesterol. In addition, trans fats may increase triglycerides and inflammation.
Trans fats are found in foods that contain hydrogenated oils such as shortening and margarines. To lower your intake, choose non-hydrogenated margarines, read labels and limit convenience food consumption. Also, the AHA recommends avoiding swapping trans fats in your diet with saturated fat, another known villain that promotes coronary artery disease by increasing LDL cholesterol. Saturated fats are most often found in animal products such as high-fat meats, poultry skin, butter and full-fat dairy products.
The goal is to avoid both trans and saturated fats and instead opt for healthier options such as canola oil, olive oil and non-partially hydrogenated soybean oil. Also, try to include more fruits, vegetables, whole grains, low-fat or fat-free dairy products, nuts and legumes, lean cuts of meat, fish, and skinless poultry in your diet.
When choosing a healthy margarine spread, become a savvy shopper. By reading the Nutrition Facts on the package, you can hunt down margarines that are trans-fat-free. If you are watching your total caloric intake, many "light" or lower calorie margarine spreads also are now available.
Haley Bradley is a registered dietician at St. Patrick Hospital and Health Sciences Center.