Sign up now for Dr. Connealy's inspiring health advice & exclusive offers sent directly to your inbox.

Trans Fats Cause Memory Loss

chef holding frozen pizza
May 20, 2015
Leigh Erin Connealy, M.D.

It was a beautifully simple memory test.

A group of men 20 or older and postmenopausal women completed a questionnaire about their diets.  This gave the research team an estimate of how much trans fat they consumed.

Each participant was then given a deck of 104 cards, with one word on each. They then had to decide whether each word was new or had already appeared on an earlier card.


  • The average number of words correctly recalled was 86.
  • Each additional daily gram of trans fats consumed was associated with an estimated 0.76 fewer words correctly recalled.
  • Those with the highest trans fats consumption remembered an estimated 11 fewer words compared to those who ate the least trans fat—a greater than 10 percent reduction.

The most serious memory loss showed in “Young and middle-aged men, during their working and career-building years,” said Beatrice A. Golomb, M.D., Ph.D., lead author and professor of medicine at the University of California-San Diego.

But a trans fat-memory loss link is of concern to everyone, particularly among older people already at risk of dementia or Alzheimer’s-linked cognitive impairment and memory loss.

What—and where—are trans fats?

Trans fats occur naturally in some meat and dairy foods, but only in small amounts—around two grams per serving.

Manufactured trans fats, on the other hand, are artificial ingredients that turn liquid oils into solids at room temperature, extending the foods’ shelf life. We see them in margarines, fast foods, baked goods, snack foods, frozen pizza, coffee creamers, and some refrigerated dough.

From 1911, when Procter and Gamble introduced Crisco, the first manufactured trans fat, until the 1990s, they were considered safe and valuable additions to countless foods, keeping them “fresh” longer, keeping them stable during deep frying, and adding more flavor.

From the early 1990s and into the 2000s, though, it was increasingly clear that trans fats, including partially hydrogenated vegetable oil, increase the risk of coronary heart disease, probably by raising “bad” cholesterol and lowering “good” cholesterol levels.

Get My FREE Curcumin Report

Chronic Inflammation Decoded

The link with heart disease, the number one killer in the US, was marked enough that Denmark banned partially hydrogenated oils in 2003, followed by other countries and by New York City, California, Baltimore and one Maryland county, which all banned trans fats in restaurant offerings.

How can you avoid or counter trans fats damage?

To avoid consuming trans fats, check the ingredients list of everything you buy.  But heads up: if it says “0 g trans fat,” it doesn’t necessarily mean what it says. There could be up to half a gram of allowed trans fats per serving.

So always also look for “partially hydrogenated oils” on the ingredients list. Those are trans fats.  Be aware also that producers are required to declare the amount of trans fats and other ingredients per serving.  So if the food you’re considering is packaged, say, four servings per package, that might be a total of two grams of trans fats by the time you finish the whole thing.

Two grams, by the way, is the American heart Association’s recommended maximum.

That’s about what you’d get naturally from those meat and dairy foods.

My own recommended maximum is zero grams of anything called a trans fat or partially hydrogenated vegetable oil.  Meat and dairy with natural trans fats are OK.

To guard against memory loss from trans fat or other causes, and because it has so many other great health benefits, I always recommend an omega-3 marine oil supplement to keep your good and bad cholesterol where they should be.

You should also add to your regimen foods and supplements that protect or enhance memory.

  • Chocolate, for example, does the opposite of trans fats—improving word memory in young to middle-aged adults. I suspect it can do the same for all of us, at any age.
  • Vitamin B-12, whether as s a supplement, or in meat, eggs, and milk is required for correct brain function
  • Enhancing your vitamin D with deliberate sun exposure and a supplement is protective against dementia.

Finally, I like the way Dr. Golumb sums it all up it. She says she tells her patients that, “while trans fats increase the shelf life of foods, they reduce the shelf life of people.”

Point well made.

Did You Enjoy This Article?

Sign up to get FREE access to more health tips, latest research, and exclusive offers to help you reach your health and wellness goals!


Get Your FREE Subscription to
Dr. Leigh Erin Connealy's Health News E-letter