Trans fat, long linked to health issues like obesity, diabetes and heart disease — and soon to disappear from many foods under orders from the FDA — is linked to memory loss in young men, a study suggests.

Men ages 45 and younger whose diets contained high amounts of trans fat did worse on a memory test than men with lower consumption levels of trans fat, researchers at the University of California, San Diego, found.

Trans fat, also known as trans fatty acids, have been used for years, mostly in processed foods such as fried chicken, doughnuts, cakes and snack foods in an attempt to improve their texture, taste and shelf life.

In the UC study, 1,018 men and women completed a survey on their diets and were then given a memory test that required word recall.

Men 45 and younger could recall 86 words in the test on average, but for every additional gram of trans fats in their daily food consumption, performance on the test dropped by 0.76 words, the researchers wrote in the journal PLOS One.

"Trans fats were most strongly linked to worse memory in men during their high productivity years," says study lead author Beatrice A. Golomb, a professor at the university's School of Medicine. "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 new finding of trans fat effects comes as the Food and Drug Administration has set out new compulsory regulations for food companies to remove trans fat from their products in the next three years.

The drop in word recall by men in the study means those with the highest trans fat intake could remember 21 fewer words than men who consumed the least, the researchers reported.

"That's a pretty sizeable effect," Golomb says.

The link between high levels of trans fat and poorer memory held even after adjusting for age, education, exercise level and ethnicity, the researchers say.

A similar association between trans fat and memory problems was not seen in older groups, likely because dietary effects on the brain and body show more clearly in younger adults, Golomb says.

While the exact mechanism by which trans fat might be affecting memory is as yet unclear, one possibility is that it acts as a stressor on cells, which could affect memory and cognitive function, she suggests.

Whatever the reason, the link is strong enough that people should take a close look at their trans fat consumption, she urges.

"As I tell patients, while trans fats increase the shelf life of foods, they reduce the shelf life of people," she says.