Is plant-based meat healthier than animal-based meat?

Plant-based meats are slightly inferior to animal meats in providing essential amino acids, but they are still an acceptable choice for most people.

Most people like to eat meat because it is the best source of protein. Humans' love for meat is written in their genes.

Among the three major nutrients, the only function of carbohydrates is to provide energy, and the main function of fat is the same. Only protein can not only provide the energy needed for metabolism, but also undertake many important physiological functions. For example, the main component of enzymes is protein, and the main component of muscles is also protein. In addition, unlike carbohydrates and fats, proteins can not be easily stored and saved for later use, so we must consume a certain amount of protein every day.

However, protein is a bit special. Our body does not consume protein directly, but must first break it down into amino acids before it can be used by the human body. There are 20 kinds of amino acids that make up protein, and in theory they can be converted into each other. However, there are 9 kinds of amino acids that the human body cannot synthesize independently and can only obtain from food. They are called essential amino acids for the human body. Therefore, to evaluate the quality of a food protein, we must not only look at the content, but also whether it contains these 9 essential amino acids for the human body. The vast majority of proteins from animal sources meet this condition, and the ratio of amino acids is similar to that required by the human body, so animal protein is considered to be a higher quality protein, including dairy products. Proteins from plants often lack some of these amino acids. For example, most beans lack methionine, so if a person only eats a certain kind of plant food, there will be problems.

Although the protein quality of most plant foods is not high, it does not mean that a person must eat meat to survive. Because different plant foods lack different amino acids, they can be combined to get the full range. For example, most grains contain methionine, so if a person eats rice or flatbread with some lentils or chickpeas, it will be fine.

Nowadays, people's living standards have improved, and the requirements for food nutrients have also changed. Not only do they require high protein content, but they also require that the nine essential amino acids are also required to be easier to digest. Because the digestibility of proteins from different sources is different in the human body, this results in the essential amino acids contained in some foods not being well absorbed and utilized by the human body.

In order to reflect this difference, the Food and Agriculture Organization of the United Nations (FAO) has developed a new amino acid evaluation system called "Digestible Essential Amino Acid Score" (DIAAS in English). This evaluation system selects pigs (rather than mice) that are more similar to the human physiological structure as experimental animals. The experimenters first fed different foods to the pigs, then took samples from the pigs' ileum to analyze the absorption of various amino acids, and then converted them into human needs of different age groups. According to the conversion results, foods with more than 100 points are rated as "excellent", which means that this food performs well in providing essential amino acids for the human body and can even be used to balance some foods with poor performance. Conversion results between 75 and 100 points are rated as "good", which means that this food is still a reliable source of essential amino acids for the human body, but it cannot be used to make up for other foods with poor performance.

According to this standard, most animal meat is an excellent source of protein. The problem is that the poultry and livestock farming industry is not very environmentally friendly and consumes too much land and feed. Beef in particular not only has the lowest feed conversion rate, but also the methane produced by cattle rumination is a greenhouse gas with a greenhouse effect 25 times that of carbon dioxide. Therefore, many environmentalists are calling on humans to reduce animal meat consumption and replace it with plant meat.

Among the more popular plant-based meat brands, the most well-known ones are soy burgers and pea burgers from the United States, and new pork from Hong Kong, China. Are these artificial meats nutritionally different from real meat? This is the question that Hans Stein, a professor in the Department of Nutrition at the University of Illinois, wants to answer.

Professor Stein is a staunch supporter of the DIAAS system and has used it to test many animal meat brands. This time, he and his colleagues used the DIAAS system to compare two plant-based burger patties from the United States, as well as pork burger and beef burger patties from several different brands. The results showed that burger patties made from real meat all scored high, while soy burger patties scored high for children over 3 years old, but not suitable for infants under 3 years old. Pea burger patties scored 83 points for children over 3 years old, which is a good level, but not suitable for infants under 3 years old.

The reason why children under 3 years old are singled out and counted as one category is because children in this age group have a very high demand for amino acids. If their intake is insufficient, it will affect brain development, causing the children to "lose at the starting line."

Taking into account that hamburgers are usually eaten with bread, Professor Stein and his colleagues measured the DIAAS values ​​of complete hamburgers and found that real meat burgers still scored over 100, which is an "excellent" level, while soy burgers only scored 86 points for children over 3 years old, which does not meet the "excellent" standard.

Professor Stein wrote a paper on the results of his research and published it in the European Journal of Nutrition on September 3, 2021. The article believes that animal meat performs quite well overall in providing essential amino acids for the human body, while plant meat is inferior in comparison.

It must be pointed out that the above conclusions are only for essential amino acids for the human body, and animal products are indeed stronger in this regard. However, plant meat is healthier than animal meat in some other aspects, such as lower saturated fat content and lower cholesterol content. These advantages may not be so important for people in developing countries who just meet their basic needs, but they are very important for people in medium-developed countries and above who often have overnutrition.

More importantly, plant-based meat is more environmentally friendly. For most people in middle- and upper-developed countries, appropriately reducing animal meat consumption and switching to plant-based alternatives is still a win-win choice.