The benefits of eating raw fruits and vegetables from an enzyme perspective

Author: Cui Yihui, registered dietitian, master of medicine

Reviewer: Zhu Wenli, Professor and Master Supervisor, Peking University Health Science Center

The smallest structural unit of the human body is the cell. The total number of cells in the human body from head to toe is 60 trillion to 100 trillion. Such a huge group of cells is not static, but is "moving" every moment. Only when cells can "move" and have active metabolism can the vitality of the human body be maintained. Various biochemical reactions are continuously carried out in each cell of the human body 24 hours a day, so the human body is compared to a huge "chemical factory".

All chemical reactions in the huge and sophisticated "chemical factory" of the human body must involve an important substance, that is, enzymes (of course, enzymes also need assistants, which are what we often call coenzymes, such as B vitamins, which are a very important type of coenzyme). How important are enzymes? In short, once enzymes are lacking, these chemical reactions will proceed very slowly or simply stop working. A scientist expressed the significance of enzymes in this way: "If the human body is compared to a light bulb, enzymes are like electric current. A light bulb will only light up when it is powered on. Without enzymes, the human body is just a light bulb that will not light up."

Some scientific studies have shown that there are more than 20,000 enzymes in the human body. There are two sources of these enzymes: one is synthesis by the human body, which can be called endogenous enzymes; the other is obtained through food, which can be called exogenous enzymes. According to the different division of labor, endogenous enzymes are mainly divided into two categories: digestive enzymes and metabolic enzymes. Digestive enzymes are responsible for the digestion of food, especially the digestion and absorption of the three important nutrients of protein, fat and carbohydrates. Metabolic enzymes are responsible for maintaining various metabolic activities of human cells. We produce 1 trillion to 2 trillion new cells every day, and at the same time, almost the same number of old cells die. Metabolic enzymes play a huge role in this metabolic process.

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The total amount of enzymes that the human body can produce every day is fixed. If one type of enzyme is synthesized more, the amount of the other type of enzyme will decrease. Under normal circumstances, the proportion of digestive enzymes in the human body is less than that of metabolic enzymes, and the ratio of the two needs to be maintained in a relatively stable equilibrium state to ensure the healthy operation of the human body. If the consumption of digestive enzymes increases due to adverse factors in the environment (such as water pollution and food additives) or bad dietary habits (eating high-sugar foods, high-fat foods, foods containing trans fatty acids, etc.), the body will tend to synthesize more digestive enzymes, thereby affecting the number of metabolic enzymes synthesized, and the balance between the two will be broken. In the long run, the healthy balance of the human body will also be broken. The exogenous enzymes that the human body obtains through food are basically food enzymes with digestive effects. Therefore, when the intake of exogenous enzymes is sufficient, the digestive enzymes in the body will be saved, so that the body can concentrate on synthesizing enough metabolic enzymes, thereby ensuring that the various metabolic activities of the human body can proceed in an orderly manner. However, due to the lack of sufficient knowledge about enzymes, as well as the Chinese cooking methods and bad eating habits, we rarely have the opportunity to obtain exogenous enzymes from food to save digestive enzymes in the body. Because one of the characteristics of enzymes is that they are not heat-resistant, when the temperature is greater than 55°C, the enzymes will be destroyed and inactivated, so whether it is steamed rice, fried or boiled vegetables, or boiled soup or porridge, the enzymes in them have "disappeared".

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On the one hand, the enzymes in the human body are consumed wantonly, while the body's ability to produce enzymes decreases with age, and the "holding amount" of "enzymes" is decreasing year by year; on the other hand, eating habits and cooking methods make it difficult for us to directly obtain exogenous enzymes. Therefore, even if the quality of life of modern people has improved, they are more likely to be in a sub-healthy state. Whether it is human aging or sub-health, it is related to the adequacy of the "enzyme reserves" in the body. Knowing these "dilemmas" of enzymes, what do we need to do for ourselves in our daily diet? You can set a small goal first, starting with the following 3 points.

❖ Do not be picky about food and reduce unnecessary processing steps. Especially for fruits and vegetables, try to eat them raw or use a food processor to make fruit and vegetable juice or smoothies.

❖ Make your diet colorful and varied. Eat 3 different colored vegetables and fruits every day and 5 different colored vegetables and fruits every week.

❖Try to eat fresh vegetables and fruits in season.

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