The World Health Organization (WHO) estimates that trans fat intake leads to more than 500,000 deaths from cardiovascular disease per year and says diets high in trans-fat increase heart disease risk by 21% and deaths by 28%.
For this reason, the additive has been banned in a number of countries including Denmark, Norway, Iceland, Hungary, Austria, Switzerland, Canada and the US, but not the UK.
Now, adding to the evidence against trans fats, this study by Kyushu University researchers in Japan reveals that, after adjusting for other dementia risk factors, study participants with the lowest levels of trans fats were 52% less likely to be at risk of dementia than those with the highest levels.
The study, published in the journal Neurology, included more than 1,600 people without dementia. Their average age was 70, and they were followed for an average of 10 years. During that time, 377 of them developed dementia.
Of the 407 who started the study with the highest levels of trans fats in their blood, 104 developed dementia, a rate of 29.8 per 1,000 'person-years' (a formula that accounts for the number of people in a study and how long they were followed).
Among those with the second-highest level of trans fats, the rate was 27.6 per 1,000 person-years. The rate was 21.3 among those with the lowest trans fat levels in their blood.
Foods that contributed the most to high blood levels of trans fats included sweet pastries, margarine, candies and caramels, croissants, non-dairy creamers, ice cream and rice crackers, according to the study.
Lead Author Toshiharu Ninomiya, professor of epidemiology and public health: "These results give us even more reason to avoid trans fats. These public health efforts have the potential to help prevent dementia cases around the world, not to mention the decrease in heart disease and other conditions related to trans fats."
In April 2019, the European Commission adopted a regulation that sets a 2% legal limit to the amount of trans fats in processed foods and, in May, the International Food & Beverage Alliance (IFBA) set a goal of phasing out industrially produced trans fats (iTFAs) from the global food supply by 2023.
Ninomiya. T., et al.
Serum elaidic acid concentration and risk of dementia