Trans Fat in Processed Foods Linked to Poor Memory Function

fries_trans fat
It’s well-known that partially hydrogenated oil is bad for heart health, but it can also impact mental function. REUTERS/Francois Lenoir

Earlier this week, the U.S. Food and Drug Administration finalized guidelines that will require food manufacturers to remove artificial trans fat from all products within the next three years—and for good reason. Partially hydrogenated oil, the primary source of trans fat in our food supply, has been linked to a number of serious and even fatal health conditions, including obesity, heart attack and stroke. But research also finds that loading up on processed food filled with this additive can have a significant impact on brain function as well.

A new study published Wednesday in the journal PLOS One adds to this growing body of research and finds eating trans fat may impede memory function in men age 45 and younger.

The study involved 694 men and 324 women all age 20 and older, who were originally screened to participate in a study on statin drugs. The researchers primarily chose to base their findings on men because there were disproportionately fewer women in the study and most were older. For this study, each participant completed a survey about eating habits, as well as a word-recall memory test.

The researchers found that for men age 45 and younger, memory was significantly impacted by junk food consumption. After adjusting for factors such as exercise habits, education, age and ethnicity, the researchers reported a direct link between a diet high in trans fat and poor memory for this age group. The more trans fat men is this age group ate, the more words they forgot on the test. On average, men in this age group dropped 0.76 words for every extra gram of trans fat eaten. This adds up to 12 fewer words recalled by young men who consumed the highest amount of trans fats in the study.

The researchers say the effect of trans fat on memory is likely due to oxidative stress, which is an imbalance of the production of free radicals and the body's ability to neutralize or counteract their harmful effect. Free radicals are a highly reactive form of atoms produced in the body by biological processes or through environmental factors that cause damage on cellular level. Examples include the impact of cigarette smoke, pollution and, of course, certain food.

Human cells become damaged as a result of free radical accumulation over time. This process is linked to a number of chronic age-related health conditions, including diabetes, heart disease, dementia and cancer.

"Trans fats were most strongly linked to worse memory in men during their high productivity years," Dr. Beatrice A. Golomb, lead author and professor of medicine at U.C. San Diego School of Medicine, said in a press statement. "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."