Dietary trans fat is associated with an increased risk of all-cause dementia and Alzheimer’s disease, according to new findings from Japan.

Researchers followed more than 1,600 older adult participants for up to 10 years. Among the 377 people subsequently diagnosed with dementia, significant correlations were found for higher elaidic acid levels in the blood (a marker for trans fat) and heightened odds of dementia and Alzheimer’s disease. People who consumed the highest amounts of trans fat were 52% more likely to develop dementia than those who consumed the least amount.

The link remained significant after adjusting for traditional dementia risk factors as well as dietary factors, reported lead author Toshiharu Ninomiya, M.D., Ph.D., of Kyushu University. These included total energy intake and intake of saturated and polyunsaturated fatty acids. 

“These results give us even more reason to avoid trans fats,” said Ninomiya. “In the United States, the small amounts still allowed in foods can really add up if people eat multiple servings of these foods, and trans fats are still allowed in many other countries.”  

In the study, sweet pastries were the strongest contributor to high levels of trans fat in the blood. This was followed by margarine, candies and caramels, croissants, non-dairy creamers, ice cream and rice crackers.

The World Health Organization has called for industrially produced trans fats to be eliminated worldwide by 2023.

The study was published in the journal Neurology.