Can Trans Fats Worsen Memory?

2 min

Trans fatty acids (TFAs) are unnatural components of many processed fats, especially those that have been partially hydrogenated. Partial hydrogenation turns liquid oils into semisolid fats, much loved by manufacturers of processed foods for their longer shelf lives. Margarine, vegetable shortening and most commercial baked goods contain these artificially hardened fats and, along with them, TFAs.

We’ve known for some time that TFAs are bad for the heart and arteries. They increase total cholesterol; raise LDL ("bad") cholesterol, and lower HDL ("good") cholesterol. In addition, TFAs may have adverse effects on cell membranes and the immune system and may promote cancer and accelerate aging.

The latest on the negative effects of TFAs comes from a study at the University of California, San Diego, showing that they were associated with sub-par performance in memory tests of young men (ages 20 to 45). The more foods containing trans fats the men reported consuming on a dietary questionnaire, the worse their performance in a study that tested their memory of words. About 700 men took part in the study. They were all shown a series of 104 cards, each of which was printed with a single word. The participants were asked to state which words were "new" – that is, hadn’t appeared on earlier cards – and which were repeats. Results demonstrated that for each additional gram of trans fat a man reported consuming, he misidentified an average of 0.76 words. Those whose consumption of trans fats was highest correctly recalled 11 to 12 fewer words than the participants’ overall average of 86.

Study leader Beatrice A. Golumb, M.D., Ph.D., suggested that the oxidizing effects of trans fats may cause brain cells essential to memory to die off, and may also exert energy-sapping effects that could make brain cells less responsive. However, she noted that the study found only an association between high consumption of trans fats and poorer memory, not a cause-and-effect relationship.

In an earlier study, Golumb’s team found an association between chocolate and memory improvement. In news accounts she noted that chocolate is an antioxidant that supports cell energy, which is important to the hippocampus, the brain area that is key to memory. The investigators then decided to focus on trans fats, which have the opposite effect on cell energy.

A 2013 Food and Drug Administration (FDA) ruling that trans fats are not "generally recognized as safe" led many manufacturers to omit them from product formulations. Unfortunately, trans fats are not entirely out of the American diet. They can readily be found in processed foods, fast food, baked goods, snack foods, frozen pizza and coffee creamers.

In part because of their known health risks, the FDA requires that trans fats be listed on the labels of foods that contain them under the "Total Fat" heading. Avoid products that contain trans fat.

Andrew Weil, M.D.

Source:
American Heart Association Meeting Report Abstract 15572, “Trans Fat Consumption is Linked to Diminished Memory in Working-aged Adults.” http://newsroom.heart.org/news/trans-fat-consumption-is-linked-to-diminished-memory-in-working-aged-adults, accessed November 19, 2014