Trans Fat May Impair Memory

(Image credit: Teresa Kasprzycka/

Even as a new rule will force food companies to stop adding trans fat to food, research continues to show the negative effects of trans fat on health. Today, new findings show that consuming trans fat may be linked to worsening memory in young men, according to a new study.

In the study, researchers found that men ages 45 and younger who consumed high amounts of trans fat performed worse on a memory test than men whose consumption of trans fat was lower.

"Trans fats were most strongly linked to worse memory in men during their high-productivity years," study author Dr. Beatrice A. Golomb, a professor of medicine at the University of California, San Diego School of Medicine, said in a statement.

The Food and Drug Administration announced new regulations on Tuesday (June 16) making it mandatory for food companies to remove trans fat from food they make in the next three years.

In the new study, researchers asked 1,018 men and women ages 20 to 85 to complete questionnaires, in which they reported what they normally ate. The researchers then looked at the nutritional content of the foods listed in the questionnaires. They also gave the participants a memory test that involved word recall.

On average, men ages 45 and younger in the study were able to recall 86 words, but with each additional gram of trans fat consumed daily, their memory performance dropped by 0.76 words. This drop translates into 21 fewer words recalled by the men in the study who consumed the most trans fat (about 28 grams per day), compared with the men who ate the least. "That's a pretty sizeable effect," Golomb told Live Science. [6 Foods That Are Good for Your Brain]

The researchers focused on the link between trans fat and memory in men ages 45 and younger because the number of women in the study in the same age group was too small to draw conclusions about whether the link held true for them as well.

The link between trans fat consumption and memory was not observed in people older than 45, the researchers said. Injuries to the brain accrue with age, which may make it tough to distinguish the effects of diet on memory, they said.

Previous research has linked the consumption of trans fat to a number of negative effects on people's metabolism, levels of blood fat and inflammation, and cardiac and general health. Moreover, studies have shown that trans fat consumption may be related to behavioral and mood problems, Golomb said.

Foods that contain trans fat include baked goods (cookies and cakes), ready-to-use frostings, fried food and snacks such as potato chips and microwave popcorn, according to the FDA.

The exact mechanism of how trans fat may affect memory is not clear. One possible explanation is that trans fat act as a stressor on cells, which could affect memory and cognitive function, Golomb said.

Trans fat also promotes inflammation, which has been shown to contribute to memory problems. For example, "Alzheimer's is considered an inflammatory brain condition," Golomb said.

The third possible mechanism is that trans fat inhibits the production of molecules called long-chain omega-3 fatty acids, which the body makes from the short-chain omega-3 fatty acids that people eat when they consume plants such as flax. "And the long-chain ones are the ones that the brain actually needs," Golomb said. Moreover, omega-3s are anti-inflammatory, she said.

The new study was published today (June 17) in the journal PLOS ONE.

Follow Agata Blaszczak-Boxe on Twitter. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

Staff Writer