The National Center for Food Safety Risk Assessment released "Re-knowing Trans Fatty Acids" on March 18, 2013, which answered questions about trans fatty acids in food. I think the more important points are:

　　 1. Although hydrogenated oils widely used in food processing have been criticized for containing trans fatty acids, “refined vegetable oils are the most commonly consumed by Chinese people in trans fatty acids Main source".

　　Except for a few edible oils such as virgin olive oil, virgin linseed oil, and sesame oil, the vast majority of edible oils (whether produced by leaching or squeezing) are refined vegetable oils. This is because most vegetable oils are inedible without refining (has toxicity or very poor flavor). Refined vegetable oils are widely used in food processing, as well as in the catering industry and home cooking. For the content of trans fatty acids in common vegetable oils, please refer to the literature below.

　　 Moreover, "the oil temperature is too high and the time is too long during the process of food frying and frying will also produce a small amount of trans fatty acids." But how much trans fatty acids will be produced in the cooking process (mainly heating temperature and time), I don''t have data on this.

　　Note that most brands of coffee mates on the market do not contain trans fatty acids or are very low in content.

　　 2. Although compared with other countries, the intake of trans fatty acids in residents of large cities in China is not high (for data comparison of various countries, see the figure below), the average energy supply ratio is only 0.34% [lower than the world 1% recommended by the World Health Organization (WHO), but this does not support the point of view of some media reports that trans fatty acids have no effect on the health of Chinese people and are not worthy of attention.

　　 This is because the average intake (or median) of trans fatty acids does not represent all or most people, which is like the average income of Chinese people cannot represent the actual income of all or most people. Income is the same. If the average intake is lower than the WHO limit, it does not mean that everyone''s intake of trans fatty acids is lower than the WHO limit. Therefore, what we really should pay attention to is not (or more than) the average intake, but how many people have a trans fatty acid intake that exceeds the WHO limit (which roughly means harmful). Of course, this proportion (approximately 0.42% of residents in large cities) is fortunately not high.

　　 In short, "We cannot take this lightly, because there are still some urban residents (about 0.42%) whose trans fatty acid supply ratio exceeds 1%."

　　3. Many foods are obviously added with hydrogenated oil, why do you indicate the content of trans fatty acid is "0"? The key to the problem is what is "0".

　　According to the "General Rules for Nutrition Labeling of Prepackaged Foods" implemented on January 1, 2013, if the trans fatty acid content in 100 grams of food is less than 0.3 grams, it can be marked as "0". There are two possibilities for the content of trans fatty acids in a food to be less than 0.3 grams. One is that the food contains very little hydrogenated oil; the other is that although the food contains more hydrogenated oil, the hydrogenated oil used in it contains trans Less fatty acids. Different hydrogenated oils have a high content of trans fatty acids, some as high as 30%, and some less than 0.3% (ie "0"). Interestingly, according to US standards, foods with less than 0.5% trans fatty acids are "0".

　　The World Health Organization (WHO) recommends that the energy supply ratio of trans fatty acids should be less than 1% [the energy supply ratio of trans fatty acids refers to the percentage of energy provided by trans fatty acids to the total energy intake of the diet] , Roughly 2 grams per day [2000×1%÷9=2.2]. If a food is marked with a trans fatty acid content of 3%, that is, 100 grams of the food contains 3 grams of trans fatty acid, then obviously if you eat 100 grams of the food, the trans fatty acid intake (3 grams) will exceed the standard.

　　 4. What are the main harms of trans fatty acids?

　　Researches in recent decades have shown that excessive intake of trans fatty acids can increase the risk of cardiovascular disease (atherosclerosis) Sclerosis, coronary heart disease, hypercholesterolemia). There is much evidence in this regard, which is very convincing. There are some studies showing that excessive intake of trans fatty acids is related to other diseases such as diabetes, hypertension, cancer, etc., but the evidence is not very convincing. Considering the large number of applications of hydrogenated oils (often containing more trans fatty acids) in the food processing industry, it is understandable to treat the hazards of trans fatty acids carefully to protect the corresponding enterprises.

　　 In fact, some natural foods also contain trans fatty acids, such as ruminants, such as meat, fat, milk and dairy products such as cattle and sheep. Are these natural sources of trans fatty acids harmful to health? The “Expert Interpretation of Trans Fatty Acid Management and Related Knowledge” released by the Ministry of Health in November 2010 stated that “the natural trans fatty acids in food have not been found to have adverse health effects. There are even studies showing that natural trans fatty acids may be beneficial to human health."

　　The National Center for Food Safety Risk Assessment published "Re-understanding of Trans Fatty Acids" on March 18, 2013, stating, "There are also some studies showing that natural trans fatty acids and processed trans fatty acids have health effects. The effect is similar." This seems to imply that the trans-fatty acids from processed sources are very harmful or beneficial to health.

　　5. How to avoid excessive intake of trans fatty acids?

　　First of all, given that refined vegetable oils are the most important source of trans fatty acids ingested by Chinese, vegetable oils in cooking should be properly controlled的DOSES. Daily vegetable oil intake should be controlled at 25-30 grams ("Chinese Resident Dietary Guidelines 2007"), and we actually eat nearly 40 grams per day on average, and about 60% of people exceed 30 grams.

　　Second, processed foods containing hydrogenated vegetable oils, such as wafer biscuits, sandwich biscuits, butter bread, crisp bread, pie, various crisps, etc., have a relatively high content of trans fatty acids, and should not be consumed excessively. .