Not long ago, the World Health Organization (WHO) issued an action-guided program called “Replacement”, which plans to completely eliminate industrial trans fats used in the global food supply chain, mainly partially hydrogenated vegetable oils, by 2023.
Fat is a triacylglycerol formed from fatty acids and glycerol. Fatty acids also have different names depending on the structure. Among them, trans fatty acids are one type of unsaturated fatty acids, and fats containing trans fatty acids are called trans fats.
There are two main sources of trans fat. One is derived from natural foods. Mainly from ruminants, such as cattle, sheep and other meat, fat, milk, its trans fat accounts for 2% to 5% of total fat. The second is derived from food processing. Among them, the hydrogenation and refining process of vegetable oil is the main source. In addition, in the process of frying, frying, cooking, and frying, the oil temperature is too high and the time is too long, and a small amount of trans fatty acid is produced.
According to China’s survey data, there are two types of foods with higher trans fat content: one is natural and margarine, butter, and the other is vegetable oil.
In addition, foods such as French fries and cakes will use hydrogenated oil, and the trans fat may be higher. The average trans fat content in other foods is generally lower.
So why use hydrogenated vegetable oil for food processing? In fact, hydrogenated vegetable oil was originally used as a “shortening oil” instead of animal oil. Because the liquid vegetable oil has a poor shortening effect, it is semi-solid at normal temperature after hydrogenation, which can meet the production process and people’s taste requirements. In addition, its chemical nature is relatively stable and can extend the shelf life.
When it comes to the harm of trans fat, in fact, it has the same metabolic pathway as ordinary fat. The main health hazard is that excessive intake will increase the risk of cardiovascular disease. As for other effects, such as obesity, cancer, diabetes, etc., there is still insufficient evidence to prove its impact.
The WHO proposal to stop using trans fats and publish the latest draft guidelines is also based on this. In the draft published by the WHO, several large pooled studies have shown that large intakes of trans fatty acids increase the risk of cardiovascular disease. Trans fatty acids are not essential fatty acids, so people should try to minimize their intake.
In fact, the health hazard of trans fat is the result of long-term accumulation, but you don’t have to worry too much about it. In this regard, WHO recommends that the energy supply ratio of trans fat should be less than 1%. For an average adult, it is about the equivalent of 2.2 grams of trans fat per day.
According to our survey, Chinese people consume an average of 0.39 grams of trans fat per day, which is equivalent to an energy supply ratio of 0.16%, which is far below the WHO recommendation. But you can’t relax your vigilance, because some urban residents have a trans fat supply ratio that exceeds the standard. Considering the large population base in China, we must pay attention to the impact of trans fat on people’s lives.
So how do you avoid excessive intake of trans fats? From the survey, refined vegetable oil is the most important source of trans fatty acids in our country. Therefore, we must first pay attention to the amount of vegetable oil used in cooking. The Chinese Dietary Guidelines (2016) recommends that the daily intake of vegetable oil should be controlled at 25 to 30 grams. Second, eat less processed foods containing hydrogenated vegetable oil, such as cakes.
It is particularly important to note that while focusing on trans fats, one cannot ignore the adverse health effects of saturated fat and excessive calorie intake.
The WHO program also pointed out that excessive intake of saturated fat will increase the risk of cardiovascular disease, and it is recommended that saturated fat intake not exceed 10% of the energy supply ratio. In addition, too much total calorie intake increases the risk of developing obesity and cardiovascular disease, as well as health.
Therefore, everyone should pay attention to food diversification, balanced diet, and moderate exercise, so as to better protect health.