After the McDonald's french fries incident, the health risks of trans fatty acids have become a major concern. In the past, people have thought that saturated fatty acids are the enemy of health, refined vegetable oils to protect health, in fact, the trans fatty acids in food than saturated fatty acids are more harmful.
The latest medical reports point out that trans fatty acids and saturated fatty acids, as well as raise the body's cholesterol content, especially low-density lipoprotein cholesterol content. Large amounts of intake may cause cardiovascular disease, gallbladder disease, type II diabetes, Alzheimer's disease, cancer (such as colon cancer, prostate cancer, breast cancer), etc., but also inhibit the growth and development of the fetus and young children, endangering male reproductive function. And trans fats are not easily metabolized, usually taking more than 50 days to be metabolized out of the body.
Trans fatty acids are produced during the refining and processing of vegetable oils. Natural vegetable oils such as soybean oil, rapeseed oil, etc., are cis-structured fatty acids, because of its high degree of unsaturation, poor stability, easy to oxidation, rancidity, not easy to long-term preservation and storage, so it is necessary to carry out partial hydrogenation processing, in order to get rid of the odor of the vegetable oils and free fatty acids, aldehydes, ketones, and other harmful substances, in order to improve the quality of vegetable oils. However, in the refining process, it is usually processed at a high temperature above 250℃, and this process will produce a certain amount of trans fatty acids.
In addition, cooking too high oil temperature or repeated frying will also generate a small amount of trans fatty acids.
Resisting the temptation of taste
The hydrogenated fats and oils are solid or semi-solid, which makes the food taste more crispy and fluffy, which is why people generally find some crispy and fluffy food particularly fragrant and delicious. Margarine, frying oil, shortening, etc. are hydrogenated fats and oils, and the TFA content in them is generally between 5 and 45%, up to 65%. According to statistics, 80 to 90% of the trans fatty acids in vegetable oils used for cooking and processing in the daily diet of Americans originate from the hydrogenation of vegetable oils.
To really reduce the damage of TFA to people's health, we should reduce the intake of TFA in the diet, especially pregnant women and lactating mothers, their daily intake should be less than 2 g. To avoid and reduce the consumption of a variety of TFA-rich pastries, fried snacks, etc., and try to avoid the high temperature of stir-frying or deep-fried cooking.
To call on people to eat less fast food and high-fat desserts, especially those who often give children to buy shortening bread, crispy snacks and foreign fast food parents, must be vigilant. Reminder: When shopping for food in the supermarket, you may want to pay more attention to the following signs: Where the composition of refined vegetable oils, hydrogenated vegetable oils, semi-hydrogenated vegetable oils, margarine (milk) oils, margarine (milk) oil, artificial fats, shortening, or phytolipids, etc., it is indicated that there are trans-fatty acids, and you should try to choose fewer of these products.
Conclusion: Food oils such as olive oil, walnut oil, sunflower oil, palm oil or corn oil, and oils with a lower degree of hydrogenation do not contain trans fatty acids, and can be consumed without worry. But the amount of oil should be controlled, about 25 grams per day.