Ok, now this is big news.
As of June 18, 2018, the FDA requires companies to eliminate trans fats from their packaged food products and restaurants.
Trans fats have been used in our foods for the past 107 years (you may have heard of Crisco). Trans fats are man-made fats that are solid at room temperature. They help to increase the shelf-life of packaged foods and when used in restaurants for deep frying the oil does not need to be changed as often. While trans fast may have desirable melting properties, they have also been extensively linked to heart disease, diabetes, and stroke.
What are Trans Fats?
If you've taken an organic chemistry class you may remember cis and trans bonds. Cis bonds, found in unsaturated fats, have their hydrogen atoms located on the same side of the carbon chain, while trans bonds have hydrogens located on opposite sides of the carbon chain. This changes the structure and shape of the molecule and determines if it will be solid or liquid at room temperature.
Early chemists found that by adding hydrogens to a molecule (or to vegetable oil) through a process called hydrogenation they could change the type of fat from an unsaturated fat (liquid at room temp) to a saturated or trans fat (solid at room temp). This lead to the production of hydrogenated and partially hydrogenated vegetable oils, which have been widely used in our food supply for over 100 years. In 1911, Crisco hit the shelves and soon after became a staple in many U.S. kitchens.
It's important to note that some trans fats do occur naturally in small amounts in some meat and dairy products. However, the effects of naturally occurring trans fats have not been studied enough to determine if they have the same effects on our health as artificial trans fats. When I refer to trans fats being banned from the food supply, I am referring to just the artificial trans fats.
The Foods We Ate for the Past Century That Contained Trans Fats
Aside from Crisco and some margarines, trans fats were often found in: frying oils, doughnuts, tortilla wraps, cakes, muffins, puff pastries, frosting, cream fillings, breakfast sandwiches, frozen pizzas, popcorn, candy, fried foods, fast food, and more.
Health Implications of Trans Fat Consumption
Today, the World Health Organization estimates that 500,000 deaths due to cardiovascular disease each year are linked to the consumption of trans fats.
Until 2015, hydrogenated and partially hydrogenated oils were 'Generally Recognized as Safe' (GRAS) by the FDA. There has now been extensive research to show the negative longterm health effects of consuming artificial trans fats. The consumption of trans fats has been shown to raise LDL ('bad') cholesterol and lower HDL ('good') cholesterol and increase total triglycerides in the bloodstream. Those who consume diets high in trans fats are more likely have to a heart attack, diabetes, or stroke.
The Dietary Guidelines for Americans recommend that we keep our intake of trans fats as low as possible. However, food labeling regulations have only required food products to include trans fat on their nutrition facts panel if the product contained 0.5g or more per serving (keep in mind a serving is not currently based on the amount a person actually eats, although there are plans to move in this direction in the future). The only way to really know if a product contained trans fats was to look for hydrogenated oils in the ingredients list.
Products that were made before June 18th that contain trans fats are allowed to be on grocery store shelves until they sell out. Moving forward packaged food companies and restaurants can no longer use artificial trans fats in their products.