Recently, Ms. Xu was selecting potato chips in a supermarket and noticed that some packages were prominently labeled "trans-fat free," while others were not. She wanted to know: what is trans fat?
It is understood that trans fat, also known as trans fatty acid, is produced by artificially catalyzing the introduction of hydrogen molecules into vegetable oil. Compared to natural fats, it is low in cost and does not spoil easily at room temperature, which can extend the product's shelf life and facilitate transportation and storage. Therefore, it is widely used in foods.
Cai Honglin, a physician in the nutrition department of Peking Union Medical College Hospital, explained that trans fat is present to some extent in most Western-style pastries. Food manufacturers like it, but it interferes with the normal metabolism of essential fatty acids in the human body. Research shows that natural fatty acids can be metabolized in the blood in 3 days, whereas trans fatty acids take at least 58 days. This can lead to cardiovascular and cerebrovascular diseases such as hyperlipidemia, high cholesterol, and atherosclerosis.
According to reports, foods containing trans fatty acids mainly include coffee creamers (non-dairy creamers), cream cakes, milk-flavored pastries, salad dressings, and sandwich cookies. The World Health Organization recommends that the daily intake of trans fat should not exceed 2 grams.
Cai Honglin specifically mentioned that traditional Chinese foods such as soy milk and fried dough sticks (youtiao) produced under standard sanitary conditions do not contain trans fat and will not interfere with metabolism.