Some people are accustomed to use the color of food to illustrate the nutritional and health value of food, and come up with such things as "red food nourishes the heart", "yellow food nourishes the spleen", Conclusions such as "green food nourishes the liver", "white food nourishes the lungs" and "black food nourishes the kidneys".

　　 Actually, food color and nutrition are not necessarily related. In terms of white food, milk, flour, Chinese cabbage and lard should all be white food, but the nutritional characteristics of the four are quite different.

　　 In terms of the nature of their origin, the four are also completely different: milk is animal milk, flour is plant seeds, Chinese cabbage is cruciferous vegetables, and lard is animal fat. Although they belong to white food, they have little in common. Other white foods such as white fungus (fungus), tofu (beans), pear (fruit), garlic, have very little in common, so "white" is used to describe their "pulmonary" or "pulmonary" "The effect is very inappropriate. It cannot be said that "white food nourishes the lungs" because a few white foods such as "lily" and "pear" have the effect of "cleaning the lungs". In fact, some Chinese medicine practitioners have also recognized this problem, and the advice they have drawn is "white multiple".

In addition to white food, other colors also have the same problem. The tomatoes, red peppers, carrots, watermelons, etc. in "red food" have some things in common because they belong to the same vegetables and fruits-β-carotene is more abundant, saying that they "fill the heart" can barely be explained, but "red meat" ", the animal''s internal organs are also red, but because it contains more saturated fat and cholesterol is not conducive to heart health. On the contrary, for cardiovascular health, "white meat" (that is, white meat such as poultry, fish and shrimp) is more recommended. "Black foods" such as black fungus, shiitake mushrooms, black beans, black sesame, kelp, seaweed, soft-shelled turtle, sea cucumber, etc. are also very different from each other, and their nutritional characteristics are very different. The nutritional characteristics of common green vegetables in "green food" are more consistent (not because of the color, but because they belong to vegetables and contain more chlorophyll), but green beans are different.

　　 In fact, the color of animal food (meat and egg milk) mainly depends on the content of hemoglobin (or heme) and myoglobin, so its color is relatively single, less changes, most of them are not " "White" means "red", and occasionally there are "black" (black-bone chicken and soft-shelled turtle, whose color comes from "melanin") and "yellow" (egg yolk, whose color comes from carotenoids), and there is almost no green. The colors of plant foods (cereals, beans, vegetables, fruits) mainly come from chlorophyll and hundreds of carotenes. The color is rich in changes, red, yellow, white, black, purple, green, orange, colorful. Chlorophyll and most carotenoids (except β-carotene) have little nutritional significance. In addition, even the same variety of plants, their colors will be very different, such as yellow corn and white corn; red heart radish, white heart radish and green heart radish; green eggplant and purple eggplant; yellow soil sweet potato and white soil sweet potato... You can''t always say that red heart radish "buxin", white heart radish "bunch lung", green heart radish "bu liver"? Sometimes, the same food has different colors, such as eggs (white and yellow), eggplant (skin purple soil) White), pork belly (red and white), banana (outside yellow inside white)..., how are the functions of these foods determined according to color?

　　 is precisely because the color of food and nutrition are not necessarily related, An overview of the dietary guidelines issued by countries (localities) in the world, including the "Dietary Guidelines for Chinese Residents 2007", does not guide the practice of dietary nutrition according to the color of the food. "Dietary Guidelines for Chinese Residents 2007" is only when choosing vegetables, it is recommended to choose dark (green and red and yellow colors) vegetables, because dark vegetables have more vitamins. For most other types of food (animal foods, beans, oils, and cereals), color cannot be used to determine their nutritional and health value. What''s more, there is a large proportion of processed foods in people''s diets at present, and the colors of processed foods can be made "artificially", and the value of pigments lies here. Choosing processed foods based on color (that is, "five colors versus five organs") is not only ridiculous in theory, but also harmful in practice.

　　Conclusion: The color of food is not necessarily related to its nutritional characteristics and health value. Even if the nutritional characteristics of certain foods (such as green vegetables) have a certain relationship with their color, it is only an individual phenomenon, and individual phenomena are not The general rule is that it is unreliable to choose food according to its color. When healthy people choose food, they should follow the recommendations on food classification in the "Dietary Guidelines for Chinese Residents 2007" ("Pagoda") in order to obtain comprehensive and balanced nutrition. Certain diseases (such as heart disease, liver disease and kidney disease, etc.) when choosing food, especially cannot be based on the color of the food, the food should be selected according to the clinical nutritional treatment principles of the disease.

　　 Off topic: Some authors are willing to use "red, yellow, blue, white and black", "one two three four five", "one leg two legs three legs four legs" when doing nutritional science promotion In terms of genre, I think that this is "acceptable" and easy to accept by the audience, and may indeed play a good role in practice. But fundamentally speaking, it is actually harmful to others. Sometimes it is equivalent to spreading misunderstandings or fallacies in disguise. I urge all those who promote nutritional science to take the Chinese Dietary Guidelines 2007 issued by the Chinese Nutrition Society as the standard, and try not to compile and act on something that is true and false, mixed with right and wrong.