Why do most foreigners like to eat raw vegetables? What are the nutritional values of raw vegetables and cooked vegetables?

The nutritional and health benefits of raw vegetables are mostly based on the habit of China people to cook most vegetables before eating, while in the western diet, most vegetables are eaten raw. From the point of view of nutrition and health care, it is better to eat vegetables raw. The advantage of eating vegetables raw is to retain the vitamins and trace elements in vegetables to the maximum extent. Vitamins, carotene and volatile oil in vegetables can stimulate resistance and improve the phagocytosis of immune cells. Eating vegetables raw can fight cancer. Many vegetables contain an interferon inducer, which can stimulate human normal cells to produce interferon, and then produce an antiviral protein, and this function can only be realized on the premise of eating raw. Antiviral proteins can inhibit the growth of cancer cells, effectively regulate the body's immunity and activate macrophages, thus playing a role in preventing cancer. For example, radish contains interferon inducer. The specific method of raw food is to eat 1 5g every day, chew slowly,1time every day, and stick to it for a long time. It provides a good opportunity for tooth chewing. Raw vegetables contribute to the health of the mouth and teeth. Full chewing can stimulate saliva secretion, help food digestion, and enhance the self-cleaning function of oral cavity, which is very important for oral health care of the elderly. A large number of practices have proved that "raw food therapy" is beneficial to insomnia, listlessness, memory loss, hypertension, fundus hemorrhage and other diseases. Eating 1-2 fresh tomatoes on an empty stomach every morning has an auxiliary effect on patients with heart and brain diseases; People with swollen throats can chew green olives or carrots. Experts suggest that you can eat raw vegetables in the following ways and insist on drinking homemade fresh vegetable juice every day. Let fresh vegetables cool, add vinegar appropriately and put less salt. Carrots, cabbages, beets, cauliflower, etc. It can be ground and fermented to produce active enzymes before eating. The advantage of vegetable cooked food is that it is beneficial to the absorption of carotene. Dark green and yellow vegetables are rich in carrots, and cooked food is better. For many vegetables rich in carotene, frying or cooking in clear soup will significantly improve the absorption and utilization of carotene. Cooked food can greatly reduce the size of vegetables, making it easy for people to eat about 300 grams of vegetables in one meal. If you eat vegetables raw, it will be difficult to meet the standard because of their big size and poor taste, thus limiting the supply of nutrients. It should be noted that although vitamin C in cooked vegetables is easily destroyed, there are other relatively stable nutrients (such as calcium and iron) and a large amount of dietary fiber in vegetables, which will not be lost due to heating. The loss rate of carotene and vitamin B2 in general cooking is also low, and these important nutrients can still play a role in human health after cooking. In the process of planting vegetables, due to the pollution of water, soil and environment, they are infringed by pesticides and fertilizers to varying degrees, and toxic pollution is inevitable. The benefits of cooking vegetables after heating are self-evident and healthy. Vitamin C, folic acid and bioactive substances with antiviral and anticancer effects contained in fresh vegetables are easily destroyed when heated. In cooked food, the principle of "high temperature for a short time" should be followed in order to protect nutrients and eliminate pathogenic bacteria. Adding salt before cooking to reduce the loss of vegetable juice, and adding a small amount of vinegar or tomato pieces to cooked food can improve the preservation rate of vitamin C. Whether raw or cooked food, we should pay attention to hygiene and eat it as soon as possible. In real life, many people, especially the elderly, like to buy a lot of cheap vegetables before the farmer's market closes and leave them at home for three to five days, which causes the original fresh vegetables to wither day by day until they turn yellow. They also know that this kind of food should not be eaten more, but they are reluctant to throw it away. As everyone knows, eating this kind of food often is not only poor in nutrition, but also harmful to health. This is because vegetables contain a nitrate substance, which is non-toxic, but after a period of storage, nitrate can easily be reduced to nitrite. When nitrite is combined with some protein substances in human body, it is easy to cause canceration of normal cells in human body and bring harm to human health. Therefore, it is recommended not to buy a lot of food at once, but to prepare for one or two days. This can not only prevent carcinogens from being produced during storage, but also prevent nutrient loss to the maximum extent.