Human-made trans fats have a bad effect on heart health. So much so that, in 2015, the Food and Drug Administration (FDA) deemed trans fats unsafe for human consumption.
Trans fats raise your “bad” (LDL) cholesterol and lower your “good” (HDL) cholesterol, which increases your risk of developing heart disease and stroke, and may increase your risk of type 2 diabetes. Learn more about how high cholesterol affects the body.
Whiletrans fats have been harmful to human health since they were invented in 1900s, we didn’t actually know it until the 1990s.
The Rise of Trans Fats
Artificial trans fat (or trans fatty acids) was invented in 1901 by German chemist Wilhelm Normann. He introduced hydrogen to liquid oils which, at room temperature, produced a solid fat.
As soon as Norman patented trans fat in 1903, food manufacturers were eager to get their hands on it. That’s because products that contained trans fats had a much longer shelf life than those with heart-healthy fats (the kind found in avocado, olive oil, and nuts).
In 1911, Procter & Gamble Company introduced the first trans fat-containing food: Crisco vegetable shortening. After that, food with transfat slowly began to fill shelves everywhere.
Hydrogenation, the process used to create trans fats, was particularly important in the creation of margarine, which was used in World War II when butter was being rationed.
Trans fats became even trendier in the 1980s as fear of saturated fat increased. Companies raced to replace butter, tallow (a hard substance made from rendered animal fat), and lard (pig fat) with trans fats, because they thought the latter was healthier.
That all changed when researchers began to study the effects of trans fat on the human body.
The Fall of Trans Fats
In 1994, a study emerged indicating that trans fats raise “bad” LDL cholesterol as much as saturated fats, and that both increase the risk for heart disease.
As evidence against trans fat continued to pile up, the FDA issued a rule in 2003 requiring trans fats to be listed on nutrition labels. (Although there was one flaw: Learn more about why your label is fibbing about trans fats.)
Over the next decade, great strides were made to advocate for the fall of trans fats:
Health experts advocated to ban trans fat
Food manufacturers swapped them out for healthier fats
Andtrans fat consumption declined, according to the Centers for Disease Control and Prevention.
Then in 2015, the FDA took partially hydrogenated oils (PHOs) off the Generally Recognized as Safe (GRAS) list. (Psst … If your food containstrans fat, PHOs are what you’ll see on the ingredients list on the label.)
How to Lower Your Trans Fat Intake
Trans fats are still hidden in many foods. While it may be tough to eliminate trans fat from your diet completely, it is wise to reduce your intake of it as much as possible. Here are ways to lower your trans fat intake:
Instead of solely relying on the “0 g trans fat” listing on nutrition labels, check the ingredients for “partially hydrogenated oils” as well. If the product lists “partially hydrogenated oils,” swap for a brand without it.
Eat a diet that emphasizes fruits, veggies, and whole grains, and choose low-fat dairy products and lean meats. These are all whole foods that don't have long ingredients lists with things like PHOs.
Limit your intake of processed foods that have been known to have higher amounts of transfats, such as fast food, frozen pizza, cookies, ready-to-use frostings, microwave popcorn, crackers, vegetable shortening, and stick margarine.
Learn more about the different types of dietary fat—and which ones to eat more of.