Beware of the "bad" fatty acids around us

Source and "hydrogenation"

Decades ago, people knew that eating animal oils such as lard and butter is not good for health because they contain saturated fatty acids. Saturated fatty acids increase total cholesterol levels, especially low-density lipoprotein LDL cholesterol, commonly referred to as "bad" cholesterol, increasing the risk of coronary heart disease. Experts recommend eating vegetable oils containing unsaturated fatty acids, such as peanut oil, soybean oil, olive oil, safflower oil, corn oil, flax oil and sunflower oil. These unsaturated fatty acids are cis-unsaturated fatty acids that do not raise cholesterol levels and may also lower cholesterol.

Because saturated fatty acids are harmful to health, the food industry uses vegetable oils containing unsaturated fatty acids. However, vegetable oils are all liquid, which is not conducive to transportation and storage, and are prone to rancidity and deterioration, and have a short shelf life. To do this, manufacturers add hydrogen to unsaturated fatty acids to make them more stable, a hydrogenation process called ' Hydrogenation."

After complete hydrogenation of vegetable oils, the unsaturated fatty acids in them become saturated fatty acids and are not suitable for food processing. Partially oxidized vegetable oils are suitable for food processing. However, after partial hydrogenation of vegetable oils, the cis-unsaturated fatty acids in them turn into trans fatty acids: trans fatty acids are also formed when foods are fried at high temperatures. In addition, when unsaturated fatty acids in feed are digested in the stomachs of ruminants such as cattle and sheep, the hydrogen produced by bacteria in the stomach will partially hydrogenate the unsaturated fatty acids to form trans fatty acids. After absorption by cattle and sheep, it appears in the fat of milk and goat's milk, dairy products, and meat products. However, the content of these trans fatty acids is not high and is generally not harmful to the human body.

is widely used

Since trans fatty acids are subordinate to unsaturated fatty acids, before they were discovered to be harmful to health, they were always regarded as a health-friendly substitute to replace saturated fatty acids, making them widely used.

Hydrogenated oils containing trans fatty acids are widely used in food processing. They make foods such as cakes, breads, Indian pancakes and egg yolk pies soft and have a unique taste; make baked goods such as biscuits, breads, etc. have a softer taste; Make fried chicken and French fries in fast food more crispy; at the same time, it can extend the shelf life of foods.

The harm is considerable

It was not until the early 1990s that researchers at Har