“It is not always easy to make sense of the research on trans fats but here’s the short answer: if you can avoid trans fats, you should. These fatty acids may be only a small part of your total dietary fat, but small changes in your diet can add up to significant health benefits, and this is one change that is well worth making.” Marion Nestle
Most people are aware that trans fats are not healthy, but do they know why? Just another one of those food “rules” we try to follow, but find it difficult to because we don’t really know what is at stake if we don’t. Well, I hope this blog answers some of those questions.
What are trans fats?
In a nutshell, the hydrogenation process makes it possible to produce partially hydrogenated fat – often referred to as trans fatty acid or trans fat. This process takes a liquid-based oil, such as soy oil, and hydrogenates it (adds hydrogen to an oil) to become a hardened solid. It was the first man-made, unnatural fat to join our food supply.
The story behind trans fats
In 1869, Napoleon III offered a prize to anyone who could invent a substitute for butter, which was too expensive and scarce in wartime. The winner concoted a grayish, white mixture of beef fat and milk called oleomargarine – thus, the term margarine was born. As time passed, the beef fat was substituted with cottonseed oil, then with soybean oil. Margarine caught on, even though it did not taste or look like butter – people would mix yellow food coloring in to make it look like butter!
Many American kitchens were first introduced to partially hydrogenated vegetable oil in 1911 with the product Crisco®. Trans fats also gained widespread popularity during World War II, when many people began using margarine and shortening as alternatives to rationed butter. Today, partially hydrogenated oil is used in many shelved foods (see list below) to extend shelf life, and also for stability in frying foods in restaurants and fast-food chains. Hence, if you eat a lot of snack foods and fried foods, your intake of these trans fats is likely to be high.
Foods that usually contain high levels of trans fats:
- Microwave popcorn
- Pastries and cakes
- French fries
- Fried chicken
- Potato chips
So why avoid trans fats?
As more and more people used this cheaper “version” of butter, cardiologists began to notice an increasing prevalence of coronary heart disease. It became clear that diets high in saturated fats raised blood cholesterol levels, and in turn, increased the risk of heart disease. They have also been shown to lower HDL (“good”) cholesterol while increasing LDL (“bad”) cholesterol, which makes it a double whammy for your heart. One possible explanation for the increase of type 2 diabetes in children and adolescents since the 1980’s is the addition of trans fats to many snack foods.
Read the Ingredients!
When looking at a nutrition label, you must read the ingredients! Look for the words hydrogenated oils, partially hydrogenated, or fractionated oils.
Smart - yet deceitful- marketing: Labels can say "0 grams of Trans Fat" even if partially hydrogenated oils are listed in the ingredients, so long as a serving size contains less than 0.5g of trans fats. The catch is that all those fractions of a gram add up if you eat more than a single serving.
A good guide is how high up the list of ingredients the trans fats are. The higher the listing, the more trans fat there is. If you want to be more specific, add up the listings of the other fats and take it away from the total fat content, the difference is usually all trans fats.
Take home message: As much as possible, try to avoid products with trans fats, and always read the label. Be smart, be healthy.