Trans fatty acids are formed when oils are exposed to high heat and high pressure in the presence of hydrogen gas, a process called hydrogenation. This makes an unsaturated fat more solid at room temperature, which extends its shelf life and improves texture in processed foods.
Are trans fatty acids unhealthy?
It was once thought that these fats were better than saturated fats because they were unsaturated. We now know that trans fats increase LDL cholesterol (bad cholesterol) and they decrease HDL cholesterol (good cholesterol), a dangerous combination that increases risk for heart disease.
What foods contain trans fatty acids?
Trans fat can be identified in foods as partially hydrogenated oils. Any product that lists partially hydrogenated oil on the ingredients list will contain trans fatty acids. The good news is that due to increased awareness and nutrition labeling laws, fewer foods contain trans fat, and intake has decreased in recent years.
Common foods that contain trans fatty acids are:
- Commercial baked goods (cakes, cookies, doughnuts)
- Fried foods (French fries, fish sticks, fried chicken)
- Margarine and vegetable shortenings
- Chips and crackers
Small amounts of trans fat occur naturally in meat and dairy products. According to The Mayo Clinic, the trans fats in processed food formed through hydrogenation appear to be more harmful than the small amounts of naturally occurring trans fat.
How much trans fat can I eat?
The Institute of Medicine recommends that trans fat intake be as low as possible. The American Heart Association recommends that trans fat be 1% or less of your total daily calorie intake.
Should I rely on food labels for trans fat information?
Since 2006, the Food and Drug Administration has required food manufacturers to list trans fat on the Nutrition Facts label. Unfortunately, if the food contains fewer than 0.5 grams per serving, the FDA allows manufacturers to say that the item contains 0 grams of trans fat. These small amounts that slip through the cracks add up. The only way to play it safe is to read the ingredients and exclude foods that contain hydrogenated oils. Better yet, choose minimally processed foods for the bulk of your diet, such as fresh fruits and vegetables, whole grains and cereals, beans and legumes, low-fat or fat-free dairy products, and nuts and seeds.