There are two sources of trans fatty acids in food, namely natural source and processing source. Natural food is mainly ruminant meat, fat, milk and dairy products such as cattle and sheep. The processing source is mainly produced in the hydrogenation and refining process of vegetable oil. When the oil temperature is too high and the time is too long, a small amount of trans fatty acid will be produced during the frying and frying process, and the trans fatty acid from processing source is the focus of attention.
According to the survey, half of the people who eat beef and dairy products come from China.
Some people once mistakenly believed that trans fat would be deposited in the body and could not be metabolized. Studies have shown that the metabolic pathway of trans fat is the same as that of ordinary fat, and there is no difference in the metabolic pathway of trans fat in infants, children, adolescents and adults. Some studies have shown that trans fats interfere with the metabolism of other essential fatty acids. However, the EU believes that as long as the intake of essential fatty acids is appropriate, it will not be affected.
The relationship between trans fatty acids and health effects such as obesity, cancer, diabetes, growth and development, reproductive health, Alzheimer’s disease, depression, violence tendency and other health effects is still unclear in the academic community. What is more clear is its association with cardiovascular disease. At the same time, the academic consensus is that trans fatty acids are not essential fatty acids for human body and have obvious potential health hazards.
In recent decades, studies have shown that excessive intake of trans fatty acids can increase the risk of cardiovascular disease, such as lowering “good” HDL cholesterol and increasing “bad” LDL cholesterol. However, there is not enough evidence that trans fatty acids can cause other harm.
It’s true to eat less trans fatty acids, but it’s almost impossible to eat any trans fatty acids at all, because they are found in cattle, sheep and dairy products. This is why the nutrition guidelines of various countries do not propose “removing trans fatty acids from the diet”. The recommendation of the American Academy of Sciences is to eat as little trans fatty acids as possible while ensuring adequate nutrition intake.
The harm of trans fatty acids to health is the result of long-term accumulation. As long as you don’t eat more, the health risk is controllable, and the key is to control the amount. In order to avoid the risk of excessive intake of trans fatty acids, the World Health Organization (who) recommended that the energy supply ratio of trans fat should be less than 1% in 2003. The energy supply ratio of trans fat refers to the percentage of energy provided by trans fat in total energy intake, which is about 2.2 g trans fat for an adult who needs 8400 kJ / d.