A new Japanese study published in 2019 in the medical journal Neurology found more evidence that suggests ingestion of dietary trans fat can increase risk of all sorts of dementia including Alzheimer’s disease. Previous observational studies have established the association.
Researchers followed 1628 men and women aged 60 years or older for a median 10.2 years and found 377 of them developed some type of dementia.
They found a relationship between elaidic acid levels and risk of dementia. That is, study participants with higher serum elaidic acid levels were 50 to 75% more likely to develop all cause dementia and Alzheimer’s disease.
Elaidic acid is a biomarker which is present in industrially made trans fatty acids used to monitor the serum level of trans fat in the study. This trans fat itself is not correlated with risk of vascular dementia – a type of dementia in this study.
Numerous studies have shown that dietary trans fat can be responsible for more than 100,000 heart disease associated deaths. In the United States, 650,000 people die every year from heart disease, which is the number one killer in the country.
The form of trans fat used in foods sold by food industry and food service industry is known as partially hydrogenated vegetable oil. These trans fatty acids affect the vascular arteries by increasing the harmful LDL cholesterol and decreasing the beneficial HDL cholesterol. As a result, this increases risk of heart attacks, strokes and Alzheimer’s disease.
Serum elaidic acid concentration and risk of dementia
The Hisayama Study
Takanori Honda, Tomoyuki Ohara, Masakazu Shinohara, Jun Hata, Ryuji Toh, Daigo Yoshida, Mao Shibata, Tatsuro Ishida, Yoichiro Hirakawa, Yasuhiro Irino, Satoko Sakata, Kazuhiro Uchida, Takanari Kitazono, Shigenobu Kanba, Ken-Ichi Hirata, Toshiharu Ninomiya
First published October 23, 2019, DOI: https://doi.org/10.1212/WNL.0000000000008464