Americans have been unknowingly eating their way to a weaker memory. Researchers at the University of California’s San Diego School of Medicine studied consumers and found a link between memory loss and a diet heavy in trans fatty acids (dTFA), more commonly known as trans fats.

"Trans fats were most strongly linked to worse memory in men during their high productivity years," the study’s lead author Dr. Beatrice Golomb, professor of medicine at UC San Diego School of Medicine, said in a press release. "Trans fat consumption has previously shown adverse associations to behavior and mood — other pillars of brain function. However, to our knowledge, a relation to memory or cognition had not been shown."

The research team administered a word recall memory test to 1,018 men and women, who were then asked to fill out surveys on their everyday diets. Men 45 years and younger were able to recall 86 words on average, but the more trans fats they consumed each day, the lower their memory performance. For every additional gram of trans fat they ate, their recall dropped by 0.76 words. Those who ate the most trans fats recalled 12 fewer words than the men who consumed no trans fats at all.

There are two different types of trans fats — one is natural and the other artificial. Naturally occurring trans fats are produced in the gut of animals, which is in turn eaten by humans through milk and meat products, according to the American Heart Association. Artificial trans fats, on the other hand, are the ones causing memory loss. They’re chemically altered by adding hydrogen to liquid vegetable oils, turning them into solids. The industrial process makes them inexpensive, easy to use, and increases the food's shelf life.

Before 1990, very little was known about how trans fats affect the body. But after years of accumulating data, it’s become clear and proven trans fats raise your bad cholesterol levels (LDL) and lower your good cholesterol levels (HDL). Eating processed foods, which more often than not contain trains fats, increases your risk of developing heart disease, stroke, and type 2 diabetes.

Eleven years ago the Center for Science in the Public Interest deemed artificial trans fats as too unsafe for human consumption, and requested the Food and Drug Administration label it as unsafe. Tuesday, the FDA agreed and determined the partially hydrogenated oils were no longer “generally recognized as safe.”

There are many foods laced with trans fats, which is why it’s important to check the back of packages, even the ones you wouldn’t expect to contain trans fats. However, food industries in America are not required to list trans fats if one serving contains less than half a gram. How many times have you reached into a chip bag and eaten more than one serving? The halves can add up quickly.

Once the FDA finalizes its decision, trans fats will become food additives that are banned unless companies petition the FDA for a special permit for use and approval. They’ll have three years to remove the ingredient from their foods. In 2013, the FDA made a tentative determination that trans fats weren’t safe for regular human consumption, and after years of public comments and scientific reviews, this has been its final verdict.

As a primary care doctor, Golomb recognized the problem with having trans fats in the human diet early on. She said, "As I tell patients, while trans fats increase the shelf life of foods, they reduce the shelf life of people.”

Processed Foods With Trans Fat:

  • French Fries
  • Potato Chips
  • Doughnuts
  • Fried Chicken
  • Microwaveable Popcorn
  • Biscuits
  • Margarines
  • Frostings
  • Coffee Creamer

Source: Golomb DA and Bui AK. PLOS ONE. 2015.