The old and new theory of healthy eggs

  Eggs have always been a popular and high-quality food. In the era of scarcity, it was used as a “nutrition” and only patients, pregnant women, the elderly or the wealthy could often eat it. The development of agricultural technology has made eggs a conventional food material, and ordinary people can also achieve “freedom to eat eggs”.
  As a result, the question of “Will eating too much eggs be harmful?” has become a concern.

  These studies are all epidemiological investigations. What they show is that “egg consumption is related to the incidence of diabetes”, and cannot prove that there is a “causal relationship” between the two.
Do you want to limit cholesterol

  Eggs are rich in cholesterol, and cholesterol in plasma is closely related to cardiovascular status-there are quite sufficient data showing that people with high blood cholesterol are much more likely to develop cardiovascular disease. Therefore, “limit cholesterol intake” seems logical. In 1968, the American Heart Association recommended: “The daily intake of cholesterol from food in adults should be controlled to less than 300 mg.” Eggs rich in cholesterol bear the brunt, “don’t eat more than 3 eggs a week.” These recommendations were quickly adopted by other countries in the world and written into dietary guidelines.
  Later studies found that cholesterol in our body is mainly synthesized by the liver, and cholesterol in the diet is basically not absorbed; saturated fat and trans fat in the diet stimulate the liver to produce cholesterol, and the cholesterol in it is actually There is no effect. There is very little saturated fat in eggs, only about 1.5 grams in a large egg-only a small part of the controlled intake, which is not worth tangling at all. The Harvard Medical School in the United States has conducted many studies to track the food composition and medical conditions of a large number of people. The results showed that among those who ate no more than one egg a day, the incidence of heart disease, stroke or other cardiovascular diseases did not increase.
  As more and more scientific evidence supports the above conclusions, “limiting dietary cholesterol” has become unnecessary. In 2015, this recommendation was formally deleted from the US Dietary Guidelines. “There is no need to limit the cholesterol in the diet”, and it has gradually been adopted by the nutrition guidelines of various countries.
Will eggs increase the incidence of diabetes?

  Cardiovascular health is only one aspect of human health. Eggs or cholesterol have no adverse effects on cardiovascular health, so what about other aspects? For example, the relationship between egg consumption and the incidence of diabetes has attracted many studies.
  In October 2020, researchers from China Medical University published a study in the British Journal of Nutrition. This study focused on 8,545 adults who participated in the China Health and Nutrition Survey from 1991 to 2009, and analyzed the relationship between their egg consumption and the incidence of diabetes. The data shows that by 2009, 947 cases of diabetes occurred among these 8,545 people. Among them, those who eat more than 50 grams of eggs per day (equivalent to 1 egg) have a 60% higher risk of diabetes than those who rarely eat eggs. Especially in women.
  This result is a bit surprising. But this is not the first, let alone the only study to explore the relationship between egg consumption and the risk of diabetes. As early as 2009, foreign studies revealed similar phenomena.
  In 2020, the “American Clinical Nutrition Research” published a review published by Harvard and other research institutions, which summarized data from three large-scale health studies in the United States, involving more than 210,000 people and an average tracking time of nearly 30 years. It was found that among those who did not have diabetes in the first place, a total of 20,514 diabetic patients occurred during the decades of follow-up. Compared with people who rarely eat eggs, people who eat one or more eggs a day have a 14% higher chance of getting diabetes.
  That paper also summarized 16 other epidemiological surveys, with a total number of close to 600,000, of which more than 40,000 diabetic patients appeared. Further analysis showed that in the United States, people who ate one or more eggs a day had an 18% increase in the risk of diabetes; in Europe, it had no effect; and in Asia, it even decreased by 18%.
  These are all officially published normative studies. We cannot say which studies are reliable, nor can we say that other studies are unreliable. In the field of nutrition, these results need to be summarized and analyzed.
  It should be pointed out that these studies are all epidemiological surveys, and what they show is that “egg consumption is related to the incidence of diabetes”, and cannot prove a “causal relationship” between the two. Although in data analysis, researchers will try to eliminate the influence of “confounding factors”, but in fact it is difficult to completely eliminate them. For example, in the issue of “U.S. Clinical Nutrition Research” that published Harvard’s large-scale review, a commentary by Canadian scholars was also published. In response to the three large-scale surveys, the comments pointed out: People who eat more eggs have a higher BMI (Body Mass Index, which is a commonly used international standard to measure the body’s weight and health), and exercise less, and at the same time Also use less lipid-lowering drugs; “Although the author carefully adjusted these confounding factors, low egg consumption may also be just a sign, which means that people have better health awareness and are more inclined to other healthy diets and lifestyles. These are difficult to be fully included in the variables of statistical analysis.” The
  comment also mentioned that there are some small-scale randomized controlled studies that found that eating more eggs did not increase fasting blood sugar and blood lipids-which is a routine of diabetes index.
  In addition, a survey involving 147,000 people from multiple countries did not show that the amount of eggs consumed was related to fasting blood sugar and blood lipids.
  In other words, it is not rigorous to conclude that “eggs increase the incidence of diabetes” based on the results of these current epidemiological investigations. Therefore, the review’s conclusion is: “Use of eggs in moderation (ie 1 per day) is a safe and affordable source of high-quality protein, which can be used as part of a healthy diet. A healthy diet emphasizes moderate intake of diversified food”.
How to eat is more important

  In terms of nutritional composition, there are few foods as excellent as eggs. In addition to high-quality protein, eggs also contain many nutrients that are easy to lack. For example, lutein and zeaxanthin are good antioxidants, which are helpful for eye health; choline is a material needed for brain and nerve health, especially for children, and it is also rich in vitamins and minerals. Moreover, its saturated fat and carbohydrate content are very low, as a part of “full nutritional balance”, it is easy to match with other foods.

  However, more important than eating a few eggs is how to eat eggs. In Europe and America, eggs are often eaten with butter, cheese, bacon, sausage, muffins, scones, French fries, bread, etc., or they are one of the raw materials for making pastries. While eating eggs, saturated fat and refined carbohydrates and sugars are also important factors that increase health risks. In addition to refined carbohydrates that directly increase the risk of diabetes, such a diet reduces fruits and vegetables, increases obesity, and indirectly increases the risk of diabetes.
  In China, many people like boiled eggs, steamed eggs, and poached eggs. These are good ways to eat eggs. Stalling eggs, green onion scrambled eggs, toon scrambled eggs, green pepper scrambled eggs, moss pork, egg soup, etc., are also good ways to eat. Relatively speaking, the methods of scrambled eggs, cakes, and baked desserts are relatively less nutritious and healthier.
  In general, judging from the current scientific evidence, eating one egg a day is still a prudent and healthy choice.