Trans fats may lead to poorer memory for young, middle-aged men

Trans fats are deemed the worst type of fat to consume. Commonly found in processed foods, trans fats raise "bad" cholesterol levels while lowering "good" cholesterol levels, increasing the risk of cardiovascular disease. Now, a new study has identified another reason not to eat these fats - they may worsen memory for men aged 45 and younger.

Higher consumption of trans fats was linked to poorer memory among men aged 45 and younger.

Researchers at the University of California-San Diego (UCSD) School of Medicine published their findings in the journal PLOS ONE.

Naturally occurring trans fats, also referred to as trans fatty acids, are produced in the gut of many grazing animals, which is why they can be found in meats and dairy products in small amounts.

However, the trans fats of concern are partially hydrogenated oils, which are manufactured forms added to foods in order to improve their taste, texture and shelf life. Potato, corn and tortilla chips, frozen pizzas, cakes, cookies and fast foods are just some products that commonly contain manufactured trans fats.

On Tuesday, the US Food and Drug Administration (FDA) announced they are planning to remove partially hydrogenated oils from all foods by 2018 due to concerns about its health implications.

The FDA's action on this major source of artificial trans fat demonstrates the agency's commitment to the heart health of all Americans. This action is expected to reduce coronary heart disease and prevent thousands of fatal heart attacks every year.

The FDA's move may also have another potential, though unintended, benefit for consumers, afterthe researchers found higher consumption of trans fats may reduce memory function for men under the age of 45.

Higher trans fat consumption linked to lower word recall in men

To reach their findings, the team analyzed data of 1,018 participants - the vast majority of whom were men - who completed a food questionnaire detailing their daily consumption of trans fats.

The participants also completed a word recall test as a measure of memory. The researchers found that men aged 45 and younger could recall an average of 86 words in the test.

However, for every 1 g increase in daily consumption of trans fats, they remembered 0.76 fewer words. Compared with men aged 45 and younger who consumed no trans fats, those who consumed the highest amounts remembered around 12 fewer words, according to the results.

These results remained even after the researchers accounted for men's age, ethnicity, exercise, education and mood.

Though few women were included in the study, the researchers say they found the same link between higher daily trans fats consumption and poorer memory when they were accounted for.

However, no association between trans fats consumption and poorer memory was identified among individuals over the age of 45. The team says this may be because older individuals experience other forms of brain damage that impair memory, which may lower the ability to detect poorer memory as a result of dietary factors.

Still, research the team's findings indicate young individuals should be cautious when it comes to trans fat consumption, not only for their heart health, but for their brain health. 

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

A 2012 study by the same researchers found that high consumption of trans fats may be associated with increased levels of aggression and irritability, while a 2011 study by Spanish researchers linked dietary trans fats to greater risk of depression.

References:

1.  A Fat to Forget: Trans Fat Consumption and Memory, Beatrice Alexandra Golomb, Alexis K. Bui, PLOS ONE, doi: 10.1371/journal.pone.0128129, published 17 June 2015.
2.  UCSD news release, accessed 16 June 2015 via Newswise.
3.  Additional source: Mayo Clinic, Trans fat is double trouble for your heart health, accessed 16 June 2015.
4.  Additional source: FDA news release, accessed 16 June 2015.