"This study demonstrates that there are negative brain / cognitive results in addition to the known cardiovascular outcomes that are related to a diet high in trans fats," said neurologist Dr. Neelum T. Aggarwal, who was not involved in the study. Aggarwal, a member of the American Academy of Neurology, is co-leader of the Rush Alzheimer's Disease Center in Chicago.
More than 1,600 Japanese men and women without dementia were followed for a period of 10 years. A blood test for trans fat levels was performed at the beginning of the study and their diets were analyzed.
The researchers then adjusted to other factors that could affect the risk of dementia, such as high blood pressure, diabetes, and smoking. They found that people with the two highest levels of trans fat were 52% and 74% more likely to develop dementia than those with the lowest levels.
"The study used blood levels of trans fats instead of traditional dietary questionnaires, which increases the scientific validity of the results," said neurologist Dr. Richard Isaacson, director of the Weill Cornell Medicine Alzheimer's Prevention Clinic. , in New York.
"This study is important because it is based on previous evidence that dietary intake of trans fats may increase the risk of Alzheimer's dementia," said Isaacson, who also did not participate in the study.
What are trans fats
Trans fats may occur naturally in small amounts in certain meats and dairy products, but by far the largest exposure comes from the man-made version.
Also called trans fatty acids, artificial trans fats are created by an industrialized process that adds hydrogen to liquid vegetable oils to make them more solid (think semi-soft margarine and fat).
The food industry loves trans fats because they are cheap to produce, last a long time and give foods a great taste and texture.
In addition to fried foods, trans fats are found in coffee creams, cakes, pie crusts, frozen pizza, cookies, crackers, cookies and dozens of other processed foods.
In the Japanese study, researchers found that sweet candies were the biggest contributors to the highest levels of trans fats. The margarine followed, followed by sweets, caramels, croissants, non-dairy creams, ice cream and rice crackers.
US regulatory action
After extensive research revealed the connection between trans fats and increased bad cholesterol (LDL) combined with a reduction in good cholesterol (HDL), the US Food and Drug Administration banned trans fats in 2015.
Companies were given three years to stop using them; so the FDA began granting extensions to various parts of the industry. The most recent extension ends on January 1st.
But even if every manufacturer goes by the first day of the year, that doesn't mean trans fats have come off supermarket shelves. According to the FDA, if a portion of the food contains less than 0.5 grams, companies may label the food as "0 grams" of trans fat.
Even in small doses, artificial trans fats will still be present to contribute to cardiovascular disease, diabetes and other conditions such as dementia.
"In the United States, the small amounts still allowed in foods can actually increase if people eat multiple portions of these foods, and trans fats are still allowed in many other countries," said study author Dr. Toshiharu Ninomiya, professor of Kyushu Fukuoka University, Japan, in a statement.
"People at risk still need to pay close attention to nutrition labels," said Isaacson. "When it comes to nutrition labels, the fewer ingredients the better! Focus on whole natural foods and minimize or avoid those that are highly processed."
Aggarwal added: "This message should be delivered in countries where the ban on trans fats has not been enacted or difficult to enforce."