An egg is the ovum of the chicken, a bird of the Phasianidae family. Also known as chicken egg or chicken ovum, it is sweet in taste and neutral in nature, with the effects of nourishing yin and moistening dryness, nourishing the heart and calming the spirit, nourishing blood and securing the fetus, and prolonging life. Eggs are a food loved by the general public. Fresh eggs are rich in comprehensive nutrition, and nutritionists call it a "complete protein model," hailing it as an "ideal nutrition library." The main nutritional components of eggs are:
1. Protein: Eggs are rich in high-quality protein. Every 100 grams of eggs contain 12.7 grams of protein, and the protein in two eggs is roughly equivalent to the protein in 150 grams of fish or lean meat. The digestibility of egg protein is also the highest among milk, pork, beef, and rice. The protein in fresh eggs is mainly ovalbumin (in the egg white) and ovovitellin (mainly in the egg yolk). Its amino acid composition is closest to that of human tissue protein, so its absorption rate is quite high, reaching 99.7%.
2. Fat: Every 100 grams of eggs contain 11.6 grams of fat, mostly concentrated in the yolk, mostly in the form of unsaturated fatty acids. The fat is in a milky, emulsified state and is easily absorbed by the human body.
3. Amino acids: Eggs are particularly rich in methionine, which is an essential amino acid that is lacking in grains and legumes. Therefore, mixing eggs with grains or legumes can increase the biological utilization of the latter. [美食中国]
4. Other micronutrients: Eggs also contain other important micronutrients, such as potassium, sodium, magnesium, and phosphorus. The iron content in the yolk is especially high at 7 mg/100g. Phosphorus is abundant in eggs, but calcium is relatively insufficient. Therefore, consuming dairy products and eggs together can provide complementary nutrition. Eggs are also rich in vitamins A and B. The nutritional value and health functions of eggs:
1. Brain-boosting and intelligence-enhancing
The lecithin, triglycerides, cholesterol, and vitellin in the egg yolk have significant effects on the nervous system and physical development. After being digested by the human body, lecithin can release choline, which can improve memory in all age groups.
2. Protecting the liver
The protein in eggs has a repairing effect on liver tissue damage. The lecithin in the yolk can promote the regeneration of liver cells. It can also increase the amount of plasma protein in the human body, enhancing the body's metabolic and immune functions.
3. Preventing and treating arteriosclerosis
American nutritionists and medical workers used eggs to prevent and treat atherosclerosis and achieved surprisingly good results. They extracted lecithin from eggs, walnuts, and pork liver and gave 4-6 tablespoons daily to patients with cardiovascular diseases. After 3 months, the patients' serum cholesterol levels decreased significantly, achieving satisfactory results.
4. Cancer prevention [美食中国]
Eggs contain a relatively large amount of vitamin B2, which can decompose and oxidize carcinogenic substances in the human body. The trace elements in eggs, such as selenium and zinc, also have anti-cancer effects. According to an analysis of cancer mortality rates worldwide, it has been found that the mortality rate from cancer is inversely proportional to the intake of selenium.
5. Delaying aging
Eggs contain almost all the nutrients the human body needs. One of the longevity experiences of many elderly people is to eat an egg every day. Many health-prescribing medicinal diets popular in China also rely on eggs. For example, eggs stewed with He Shou Wu, eggs stewed with pig's brain, egg congee, etc. When eggs are processed into salted eggs, the calcium content increases significantly, from 55 mg per 100g to 512 mg, about 10 times that of fresh eggs, making them especially suitable for people who want to supplement calcium.
6. Maintaining skin beauty
Eggs also contain a relatively rich amount of iron. 100 grams of egg yolk contains 150 mg of iron. Iron plays a role in the human body in hematopoiesis and transporting oxygen and nutrients in the blood. The ruddy beauty of a person's face is inseparable from iron. Insufficient iron can lead to iron-deficiency anemia, causing a person's complexion to become sallow and the skin to lose its beautiful luster. It can be seen that eggs are indeed one of the important foods for maintaining skin beauty. Which foods should not be eaten with eggs?
1. Eggs and milk
Milk contains lactose, which is a dimer of galactose and glucose, with galactose being its nutritional value. Eggs contain a lot of protein, which is broken down into amino acids. The absorption of amino acids consumes energy (active transport on the intestinal wall). At this time, the amount of glucose available in the blood is less, and galactose will be oxidized to provide energy. A certain protein in eggs will react with a certain nutrient in milk, reducing its nutritional value, so they should not be eaten together.
2. Eggs and soy milk
Raw soy milk contains trypsin inhibitors, which can inhibit the activity of human proteases, affecting the digestion and absorption of protein in the human body. The egg white contains viscous protein, which can bind with trypsin in soy milk, hindering the breakdown of protein and thus reducing the human body's absorption rate of protein. [美食中国]
3. Eggs boiled with sugar
In many places, it is customary to eat poached eggs in sugar water. In fact, boiling eggs with sugar causes the amino acids in egg protein to form a compound with fructosyllysine. This substance is not easily absorbed by the human body and has adverse effects on health. Misconceptions about eggs
1. Eating eggs often leads to high cholesterol
Indeed, each yolk contains more than 200 mg of cholesterol, which accounts for 2/3 of the recommended daily intake of cholesterol. So, many people are scared by this data and exclude egg yolks from their daily diet. In fact, no scientific research can prove that people who eat more eggs have a higher probability of developing heart disease than those who eat fewer eggs. So far, after examining the eating habits of about 120,000 men and women and following them for many years, authoritative studies have shown that healthy men and women who eat an average of one egg a day do not have a higher risk of heart disease or stroke compared to those who eat only one egg a week or none.
These data clearly tell us: the high cholesterol in eggs is not directly related to the high cholesterol in our bodies. Because the yolk contains relatively rich lecithin, which is a powerful emulsifier, it can make cholesterol and fat particles extremely fine, allowing them to pass smoothly through the blood vessel wall to be fully utilized by cells, thereby reducing cholesterol in the blood. Moreover, the lecithin in the egg yolk can be digested to release choline, which enters the blood and then synthesizes acetylcholine, the main substance of neurotransmitters, which can improve brain function and enhance memory. Therefore, one cannot just predict a negative impact on the risk of heart disease just because of their high cholesterol content. [美食中国]
2. Eating raw eggs is more nutritious
Some people like to eat raw eggs, thinking that the nutrients are destroyed when eggs are cooked, and that eating them raw is more nourishing for the body. In fact, this method is not only useless but also harmful. First, eggs are produced by the chicken's ovary and cloaca, and the bacteria rates of the ovary and cloaca are very high, so the eggshell surface and even the yolk may be contaminated with bacteria. Eating them raw can easily cause parasitic diseases, intestinal diseases, or food poisoning. Second, raw eggs have a fishy smell that can suppress the central nervous system, reducing appetite and sometimes causing vomiting. Third, the raw egg white contains a substance called avidin, which prevents the human body from absorbing the biotin in the egg yolk. Cooking eggs can kill the bacteria inside and outside the egg and also destroy avidin.
The latest research shows that if raw eggs are eaten in large quantities for a long time, the avidin in the raw egg white will combine with biotin in the body to form a stable compound, preventing biotin from being absorbed by the intestinal wall. This can lead to mental fatigue, muscle aches, hair loss, skin inflammation, loss of appetite, weight loss, etc. When raw eggs pass through the intestine, they can easily ferment and spoil, sometimes producing nitroso compounds. These compounds are carcinogenic, so eggs should not be eaten raw.
3. Chicken embryo eggs are beneficial to health
Chicken embryo eggs refer to eggs that have been incubated but have not developed into chicks. Folk medicine believes that chicken embryo eggs have the effect of replenishing qi, and regular consumption can make the complexion ruddy, increase appetite, strengthen the body, and delay aging. It is said that chicken embryo eggs have a high protein content because during the incubation period, the nutrients in the eggs are not destroyed but are enhanced by incubation. In addition, they contain some components similar to "human placenta," which can improve gastrointestinal function and have the effect of increasing appetite and anti-aging.
However, most chicken embryo eggs sold on the market are eggs intended for hatching chicks, which are chicken embryos that have stopped developing and died in the shell due to improper temperature, humidity, or bacterial infection. The nutrients originally contained in these dead embryo eggs, such as protein, fat, carbohydrates, inorganic salts, and vitamins, have all or partially changed, and most of them have been used and consumed by the embryo, leaving very little nutritional value.
It has been determined that almost 100% of dead embryo eggs contain bacteria. Eating such stale dead embryo eggs is not only low in nutritional value but also easy to cause poisoning, leading to diseases such as dysentery, typhoid, and hepatitis. Therefore, chicken embryo eggs are low in nutritional value and easily contaminated by bacteria. If they are not heated thoroughly and are undercooked, they can easily cause food poisoning.
4. Red-shelled eggs are more nutritious than white-shelled eggs
Red-shelled eggs are laid by so-called free-range chickens, while white-shelled eggs are laid by White Leghorn chickens, commonly called commercial chickens. The egg white of red-shelled eggs is thick, while that of white-shelled eggs is thin, leading people to believe that red-shelled eggs are more nutritious. This has no scientific basis. When the two types of chickens that lay white and red eggs are fed under the same conditions, nutritionists compared the nutritional components of white and red eggs and concluded: the protein content in red-shelled eggs is 12.4%, while in white-shelled eggs it is 13%; the fat content in red-shelled eggs is 11.2%, while in white-shelled eggs it is 9.9%; the content of other nutrients is also almost the same.
But red-shelled eggs today are not necessarily laid by free-range chickens. Red-shelled eggs from chicken farms have red shells because other things are added to the chicken feed. Their nutrition is the same as white-shelled eggs, but because people prefer red-shelled eggs, the price can be higher. This is a means of adding value. Therefore, there is no need to insist on buying red-shelled eggs from chicken farms now.
5. The more eggs a postpartum woman eats, the better [美食中国]
Some postpartum women eat more than 10 eggs a day to strengthen their nutrition, but this is not good for their health. Medical research has found that excessive intake of protein increases the burden on the kidneys. Postpartum women have reduced digestive and absorption functions, reduced liver detoxification functions, and reduced kidney's ability to remove waste. Eating a large number of eggs will加重 the burden on the liver and kidneys, leading to adverse consequences. Excessive intake of protein can also break down abnormally in the intestines, producing large amounts of ammonia, hydroxyl, phenol, indole, and other substances. These chemicals are very toxic to the human body and can easily cause symptoms such as abdominal bloating, dizziness, dizziness, limb weakness, and coma. Modern medicine calls these symptoms "protein poisoning syndrome."
The intake of protein should be calculated based on the human body's ability to digest and absorb protein. Under normal circumstances, the protein supply is 1.0-1.5 grams per kilogram of body weight per day, accounting for about 15% of the total calories, and high-quality protein should account for 40%-50% of the total protein. During the entire puerperium, a postpartum woman only needs about 100 grams of protein per day to meet her nutritional needs. Therefore, eating about 3 eggs a day is enough for a postpartum woman. Which cooking method is more beneficial for retaining the nutritional value of eggs?
There are many ways to eat eggs. In terms of nutrient absorption and digestibility, boiled eggs are 100%, scrambled eggs are 97%, soft-fried eggs are 98%, hard-fried eggs are 81.1%, eggs beaten into boiling water or milk are 92.5%, and raw eggs are 30%-50%. Therefore, boiled eggs are the best way to eat them, but it is important to chew slowly, otherwise it will affect absorption and digestion. However, for children, steamed egg custard and egg drop soup are the most suitable, as these two methods can break down the protein, making it extremely easy for children to digest and absorb. The vitamin C content in eggs is not high, so it is best to eat them with a moderate amount of vegetables.
Who should not eat eggs? Although eggs are nutritious, the following people should be cautious when eating them.
1. When a patient has a high fever, do not give them eggs to supplement nutrition, because high fever patients have reduced digestive juice secretion and decreased activity of various digestive enzymes. At this time, it is not advisable to eat high-protein, hard-to-digest eggs. They can only eat light diets, otherwise it will cause indigestion symptoms such as abdominal bloating and diarrhea, which is not conducive to recovery. [美食中国]
2. Patients with nephritis should also be cautious about eating eggs when renal function is impaired and urine output is reduced. At this time, metabolic waste products in the patient's body cannot be fully excreted by the kidneys. If they eat more eggs, excessive protein intake will increase urea in the body, which will worsen the condition. When kidney patients have renal failure, they should avoid eating eggs.
3. The cholesterol and fat in the egg yolk are metabolized in the liver, which increases the burden on the liver. Therefore, patients with liver and gallbladder diseases should control their egg intake according to their condition.
4. Allergic to protein Some patients with allergic constitutions, due to a large intake of protein-rich foods such as eggs at one time, are prone to protein allergic urticaria, experiencing symptoms such as diarrhea, abdominal pain, and skin rashes. Therefore, such patients should avoid protein-rich foods.