Artificial trans fats (found in processed foods) are made through a chemical process when hydrogen gas reacts with oil. This process solidifies the oil and makes it more stable to allow for extended shelf life, without refrigeration. They are found in cookies, crackers, icing, potato chips, stick margarine, shortening, peanut butters and microwave popcorn. Basically, if the product has been processed, it has factory-produced hydrogenated oils (usually soybean oil), which is trans fats. Many manufacturers started including trans fats in their processed foods about 20 years ago to prolong the shelf life of their products, which can be years.
Many studies have found that these fats increase coronary heart disease and stroke 5 times greater than any other fat consumed in the diet, including saturated fats found in butter and beef. In a study with over 80,000 women, for every 5% increase in saturated fat , her risk of heart disease increased by 17%. But only a 2% increase in trans fats increased the risk by 93%. The trans fats have been found to increase total cholesterol and triglycerides, while depleting the good cholesterol, HDL, while also causing an inflammatory reaction in the arteries. This was shown in another study where CRP levels (a blood test which shows arterial inflammation related to increased coronary artery disease) rose in correlation with increased trans fats consumption. Over the years, there have been many studies which have repeatedly shown the strong correlation between significant increases in heart attacks, stroke and death and the amount of trans fats consumed in the diet, which led to the actions and policies to remove trans fats from the food supply. Yet still 20% of all foods Americans consume on a daily basis contain trans fats.
What can you do to avoid trans fats? In 1996 the FDA required labeling of all trans fats and it can be found in the fat section on the nutrition label. Learn to read all food labels on processed foods. Or better yet, eliminate or limit processed foods in your diet. However, you can always tell if the product contains trans fat if hydrogenated oil is listed in the ingredients.
How much can you consume safely? The answer is unknown, but the American Heart Association recommends that no more than 1% of your total daily calories be from trans fats. If you consume 2000 calories a day, that works out to be 2 grams or 20 calories of trans fats.