Men who eat a lot of trans fats, which are found in processed foods, have poorer memory, a new study suggests.

Trans fats are artificially produced fats that are used in thousands of processed foods, from deep fried food and frozen pizza to biscuits, margarine and ready-meals.

US researchers looked at 1,000 healthy, working-age men. All of the participants had to supply details about their diet so that their level of trans fat consumption could be assessed.

They also underwent memory tests involving 104 cards displaying words. They had to say whether the word they were seeing was new or had been on another card they had seen already.

The study found that those who ate the most trans fat had the poorest memory. The findings stood even after other factors were taken into consideration, such as the participants' age, education and depression status.

The average number of words recalled was 86. However, those who consumed the highest amount of trans fats recalled around 11 fewer words - a 10% reduction in words remembered - compared to those who consumed the least amount.

"Trans fats were most strongly linked to worse memory in young and middle-aged men during their working and career-building years. From a health standpoint, trans fat consumption has been linked to higher body weight, more aggression and heart disease. As I tell patients, while trans fats increase the shelf life of foods, they reduce the shelf life of people," said the study's lead author, Dr Beatrice Golomb, of the University of California in San Diego.

The researchers called for more research to see if the results extend to women.

Details of these findings were presented at the American Heart Association's Scientific Sessions 2014 in Chicago.