Scientific understanding of trans fatty acids

Recently, the World Health Organization (WHO) reiterated its call for the "elimination" of trans fatty acids from food as soon as possible, stating that "trans fatty acids have no known benefit and pose significant health risks." So what exactly are trans fatty acids? Where does it mainly come from? What are the health risks? What should consumers think? The following scientific interpretation has been made.

Trans fatty acids are found in foods from both natural and processed sources.

Trans Fatty Acids (TFA) are unsaturated fatty acids that contain one or more non-conjugated trans double bonds in a carbon chain. There are two main sources:

01.

Natural source

Formed by the biological conversion of bacteria in the rumen of ruminants, this group of trans fatty acids is commonly found in the meat and dairy products of ruminants such as cattle, sheep and camels.

02.

Processing source

One is partial hydrogenation of unsaturated fatty acids (vegetable oils) to produce semi-solid, spreadable fats; the other is the high temperature processing of liquid fats for a long time (such as the refining and deodorization of vegetable oils), as well as the use of excessively high temperature oil (such as 220℃ above) for a long time frying, may also produce trans fatty acids.

According to WHO, excessive intake of trans fatty acids is one of the related factors for the risk of cardiovascular diseases, which can increase the serum total cholesterol (TCHO) level and low density lipoprotein cholesterol (LDL-C) level, and decrease the serum high density lipoprotein cholesterol (HDL-C) level. In adults, the daily energy supply of trans fatty acids is more than 1% (about 2.2 grams) of the total dietary energy, which may be harmful to health. That is why in 2018 WHO launched REPLACE, an initiative to eliminate trans fatty acids from partially hydrogenated fats and oils from processed sources worldwide by 2023.

Currently, dietary intake levels of trans fatty acids are low and the risk is manageable.

The elimination of trans fatty acids from processed sources is an inevitable trend in the food industry. Over the past two decades, China has taken a number of steps to reduce the health risks of trans fatty acid consumption by consumers. Specific projects include: technical research on replacing partially hydrogenated fats and reducing the production of trans fatty acids in vegetable oil refining through national scientific research projects; Continued improvements in oil and food production processes have reduced the production and use of trans fatty acids; push to reduce trans fat (acid) use through national standards for food safety, etc. At the same time, a risk assessment of dietary trans fatty acid intake among Chinese residents was conducted, and the results showed that the level of dietary trans fatty acid intake was low and the risk was manageable.

At present, margarine, shortening, cocoa butter substitute and other partially hydrogenated fats are almost no longer used as raw materials, and most refined vegetable oils have very low trans fatty acid content (that is, trans fatty acid energy supply ratio is less than 1% of total dietary energy). Therefore, consumers should not be overly concerned about the risks of consuming trans fatty acids.

Excessive consumption of trans fatty acids can be avoided by eating a sensible diet.

Consumers can avoid overconsumption of trans fatty acids by eating sensibly and checking food labels.

01

Rational diet

Follow a variety of diets and be careful to keep your daily intake of cooking oil to no more than 25-30g, while avoiding the use of repeatedly heated oil for cooking or frying food.

02

Read label

When buying prepackaged foods, check the nutrition facts list and try to choose foods that have no or low levels of trans fatty acids.