Now, any opinion that affirms or recommends drinking milk is likely to provoke criticism, citing invincible food safety issues. In sharp contrast to this, the per capita consumption of milk has increased year by year. This article first discusses a few basic questions about whether to drink milk, and then introduces the characteristics of various milks on the market.

Comparison of low-fat milk with ordinary milk, the former provides the same amount of calcium with less energy

　　1. Is milk suitable for drinking every day? Is it suitable for everyone? Can I drink?

　　This question is very easy to answer. Humans are mammals, and living on milk is a fundamental characteristic of these animals in their early life. Breast milk is a necessity during infancy, and the use of milk (formula milk powder) as a last resort can also raise the baby healthily. If you admit this, it is difficult to believe that milk is harmful to grown-up humans~ unless you can provide a large amount of sufficient evidence to prove that milk is harmful to adults.

　　 So far, there is very little evidence that milk is harmful to adults. Occasionally a few are insufficient to form a conclusion (see question 4 for details). On the contrary, there is a lot of evidence that milk (as part of a diverse diet) is good for adult health. In addition, the phenomenon of discomfort in abdominal distension after drinking milk (professionally referred to as "lactose intolerance") cannot be used as a reason to oppose drinking milk, or that milk is harmful to adults (see question 2 for details).

　　 Therefore, we can only think that milk is good for people, suitable for drinking every day, everyone (including young and adult mammals) can drink.

　　 2. What’s wrong with abdominal distension (lactose intolerance) after drinking milk? Can I still drink milk?

　　 milk contains very unique (Lack of other natural foods) lactose. This sugar has good nutritional effects (such as promoting mineral absorption, helping the beneficial bacteria in the large intestine, etc.), but it requires a small intestine to secrete a special "lactase" to digest and absorb it.

　　 Unfortunately, some adult small intestinal mucosal cells cannot secrete this kind of lactase, or the lactase activity is low (this is more common), and the lactose in milk cannot be digested and absorbed well. After the undigested lactose enters the large intestine, it is fermented by bacteria in the large intestine to produce gas (bloating); and due to the increase in osmotic pressure, the water in the large intestine increases (diarrhea), which in turn causes discomfort and abdominal pain. The severity of the symptoms depends not only on the degree of reduction in lactase activity, lactose intake, but also the influence of accompanying food and intestinal conditions, and it is also related to the individual''s ability to feel abdominal distension not suitable for abdominal pain. [Some babies also have lactose intolerance, and if there is no special feeding guidance, it often leads to serious consequences.]

　　Gene (DNA) research shows that humans 9000 years ago, like other animals, can only be digested during lactation Absorb lactose, and cannot digest and absorb lactose in adulthood. But since then, some changes have occurred in human DNA, so that adults also have lactase. This heritable change allows many adults to digest and absorb lactose. Simply put, people who are lactose intolerant carry the original gene (more common in Asians and Latin Americans), while people who can digest and absorb lactose carry new genes that have evolved (more common in Europeans).

Can 　　 lactose intolerance drink milk? The answer is yes, but some special choices are needed:

　　⑴Do not drink fresh milk and drink yogurt

After the fresh milk is fermented by lactic acid bacteria, most of the lactose is decomposed by lactic acid bacteria, which can significantly reduce the symptoms of lactose intolerance.

　　⑵ Don’t drink milk on an empty stomach

　　You can drink milk during meals or within 1 hour after a meal, or you can supplement it with cereals (such as steamed bread, biscuits, bread, etc.) ) Or meat and egg foods. In this way, the concentration of lactose can be "diluted" and the symptoms of intolerance can be reduced.

　　⑶A small amount of repeated milk

　　 can be started from a small amount (such as 50 ml) to let the gastrointestinal tract Get used to it slowly, then increase gradually.

　　⑷Select low-lactose milk

　　The so-called low-lactose milk is the decomposition of lactose (using lactase and other methods) during the production process, so the lactose content is low (≤2 %, GB28050-2011) milk. At present, there are two major dairy companies in the market.

　　 (The above measures refer to the "Guide to Healthy Diet of the Capital Citizens", edited by Beijing Municipal People''s Government)

　　3. Can milk be replaced by other foods?< /p>

　　 Infant milk is basically irreplaceable, and babies without milk cannot survive or develop poorly. Adults no longer depend on milk, and they can still live a healthy life even if there is no milk in the recipe. But in terms of nutritional value, milk can hardly be replaced by any other food (note the attributive "one").

　　Compared with other kinds of food, the nutrition of milk is more unique (such as protein, fat and sugar, etc.), but it contains high-quality protein, fat, vitamin A and zinc and other nutrients are easily found in Calcium is difficult to obtain from other foods (eg meat, eggs, fish, etc.). Milk has high calcium content and good absorption rate, which is difficult to compare with other foods. For example, soy milk, its calcium content is usually only one-twentieth of milk (that is, 20 cups of soy milk calcium is equivalent to a glass of milk).

　　In addition to dairy products, soy products such as tofu and dried tofu, green leafy vegetables such as canola, spinach, Chinese cabbage and shrimps, sesame paste and other "partial door" foods also contain more calcium, so if the recipe does not contain Milk, should increase the supply of calcium-containing foods such as soybean products and green leafy vegetables, supplement calcium if necessary (such as pregnant women and children).

　　 In short, through careful diet matching, you can get comprehensive nutrients even without drinking milk. In this sense, milk can be replaced like any other kind of food. But this does not mean that there is any food that can replace milk.

　　4. There are reports that milk is harmful to health or unhelpful, how do you view these opinions?

　　 Such reports or opinions appear from time to time. For example, a recent group of American surgeons said, “The slogan about milk helping to strengthen the bones of children is actually an ineffective placebo.” They think it’s time to remove the food milk from the child’s school lunch program Too.

　　 has controversy on most scientific issues, even major issues such as evolution and dinosaur extinction; scientific research on the same issue often leads to different or opposite conclusions. This is normal, and the argument is actually a part of scientific research, a very important part. The scientific knowledge we learn and accept is usually the conclusion basically accepted by most researchers (mainstream scientists). Therefore, the attitude towards milk and any other serious scientific issues will not be completely changed by a report, a research, or the opinions of several people.

　　 At present, health organizations including the World Health Organization, the United Nations Food and Energy Organization, the United States Department of Agriculture, the United States Centers for Disease Control and Prevention, and the Chinese Ministry of Health all affirm the important role of milk for adolescent bone health. These understandings range from theoretical analysis (milk is rich in protein and calcium, etc.) to large-scale epidemiological investigations. The evidence is abundant and sufficient, at least so far it cannot be overturned.

　　 Of course, there are some blunt propaganda, such as "a cup of milk strengthens a nation" and "milk is the closest food to ideals".

　　5. How much milk is appropriate to drink each day?

　　For ordinary adults, I think the Chinese Dietetic Association’s “Dietary Guidelines for Chinese Residents 2007” recommends daily Drinking 300 grams of milk is more reasonable. This amount of milk helps to balance the dietary structure and get more calcium. People with dyslipidemia or obesity are advised to use low-fat or skimmed milk.

　　 Certain special populations, such as children, adolescents, pregnant women, nursing mothers, the elderly, osteoporosis patients or high-risk individuals should drink more milk, such as 500 grams or more per day. At this time, low-fat milk or skimmed milk is more desirable, to avoid excessive fat intake.

　　The above amount of milk is only a rough recommended amount, not a "minimum intake" or "maximum intake limit". In fact, the minimum daily milk intake is difficult to determine. Question 3 has already been discussed. Milk and other foods are not compulsory to eat. Careful collocation of other foods can largely compensate for the shortage of milk.

　　Similarly, the daily maximum limit of milk is also difficult to determine. Out of the ancient wisdom of "too much time", it is generally believed that, like many other foods, excessive intake of milk is also harmful. Saturated fat and cholesterol are obvious harmful factors, which are harmful to the cardiovascular system. In addition, a survey did find that too much milk (800 grams, 1,000 grams or more per day) poses a health risk.

　　6. What are the characteristics of various types of dairy products

　　★Low lactose milk

　　 has been as mentioned above, yes Refers to milk with lactose ≤ 2%, especially suitable for lactose intolerant people (abdominal distension after drinking milk). Because I am lactose intolerant, I have a soft spot for this type of milk.

　　★Low-fat milk and skimmed milk

　　According to the "General Rules for Nutrition Labeling of Pre-packaged Foods"【GB 28050-2011], low-fat milk requires a fat content ≤1.5% (1.5 g/100 ml), skim milk requires a fat content ≤0.5% (0.5 g/100 ml). This type of fat-reducing milk is suitable for people who lose weight, have abnormal blood lipids, or drink more milk.

　　 I personally value low-fat milk (as shown in the picture). Because it can provide the same amount of calcium (100 mg) and similar protein (2.9 PK) with less energy (181 PK 284) 3.1 or 2.9), which is beneficial for those who are afraid of fat or fat.

　　★Skimmed milk powder

　　Skimmed milk powder has lower fat content (fat≤1.5%, milk powder 100g contains 1.5g fat, please note that it is solid milk powder instead of liquid milk), but I generally Not recommended. Because skim milk powder needs to add more sugar, remove fat and add a lot of sugar (filling volume and weight, reduce cost, improve taste), saying that it is healthier is far-fetched.

　　 But the above-mentioned low-fat milk and skimmed milk (both refer to liquid milk) generally do not need to add sugar, because water is the main component, the removal of fat will not significantly reduce the volume or weight.

　　★Pasteurized milk ("fresh milk")

　　according to the national standard for pasteurized milk【GB 19645-2010], pasteurized milk has two major characteristics, one is that the sterilization temperature is lower (compared with ultra-high temperature sterilized milk); one is that milk powder cannot be used (ultra-high temperature sterilized milk can be used). Therefore, it has less vitamin loss and higher nutritional value.

　　★Ultra-high temperature sterilized milk

　　According to the national standard of UHT milk【GB 25190-2010], the main feature of ultra high temperature sterilized milk is that the sterilization temperature is higher (at least 132 ℃), so the shelf life is very long. But vitamin loss may be more, and the nutritional value is slightly lower than pasteurized milk.

　　Ultra-high temperature sterilized milk is divided into two types according to different raw materials. One type uses raw milk (or goat’s milk) as raw material and does not add milk powder, which is called “pure milk”; the other type is based on Milk powder is the main raw material and is called "reconstituted milk". It is generally believed that the nutritional value of "reconstructed milk" is slightly lower than that of "pure milk".

　　★Modified milk

　　 This kind of milk has a variety of patterns, breakfast milk, walnut milk, children’s milk, ladies’ milk, etc. are all modulated milk [GB 25191-2010]. They are produced from milk or milk powder as the main raw material (not less than 80%), and then added with other raw materials (such as grains, vegetable powder, additives, etc.), so their nutritional value is low, and the protein content is ≥2.3% (ordinary milk ≥2.9%)

　　★yoghurt

　　yogurt is fermented milk【National Standard GB 19302—2010] One of the two main types (the other is flavored fermented milk, see below). The raw material is milk or milk powder, which is made by special strain fermentation (not reheated after fermentation). Not only the protein content is high (≥2.9%), but also live bacteria (beneficial bacteria).

　　 Containing live bacteria (beneficial bacteria) is the biggest feature of yogurt. The nutritional advantages of yogurt are all related to live bacteria and their fermentation process. Such as fermentation makes the protein easier to absorb; fermentation synthesizes new vitamins; fermentation makes lactose into lactic acid, which not only eliminates lactose intolerance, lactic acid also helps digestion, improves the absorption rate of calcium and iron; live bacteria support the growth of beneficial bacteria in the large intestine ( It cannot be simply understood that the live bacteria in yogurt directly reach the large intestine and remain alive).

　　★Flavored fermented milk

　　This is currently the most popular "yoghurt" product on the market, but strictly speaking, they are not pure yogurt. In addition to milk (more than 80%), its raw materials are also added with fruits and vegetables, cereals, food additives (such as sugar, gums, flavors, etc.), nutrient fortifiers, etc. The protein content is low (≥2.3%), and the nutritional value Lower than yogurt.

　　Of course, they are also produced by special bacterial fermentation, most of them also contain live bacteria (not reheated after fermentation), and also have the nutritional advantages brought by the aforementioned live bacteria. However, it should be noted that some products are heated after fermentation, the shelf life is extended, and there is no need to refrigerate, but the nutritional advantages brought by live bacteria are gone.

　　★Cheese and processed cheese

　　 cheese is also called cheese (national standard GB 5420-2010], in theory, it is a product of milk fermentation and concentration (moisture removal). It is said that one pound of cheese is equivalent to eight pounds and ten pounds of milk. But in fact, it is difficult to buy this kind of pure cheese on the market (consumers do not like its taste), the most common one on the market is "reprocessed cheese" (the taste is more popular, and consumers are rushing because of the unknown truth) ).

　　process cheese【National Standard GB 25192—2010] It is produced on the basis of a small amount of cheese (≥15%, pay attention to this very low ratio), adding a large amount of other raw materials (such as emulsifying salt, sour agent, soybean phospholipid, preservatives, etc.), its nutritional value is far Not as good as cheese. You like its flavor is understandable, but if you think its nutritional value is high (equivalent to a few pounds of milk), then it is too confusing.

　　 "Fresh cheese" is easy to see on the product label and keep your eyes wide when buying.

　　★Other

　　Condensed milk [GB 13102—2010], cream [GB 19646—2010], whey powder and whey protein powder [GB 11674-2010] and milk powder for pregnant women, milk powder for middle-aged and elderly people [GB 19644-2010] are also common dairy products.

　　★★★emphasis

　　There are a lot of milk drinks (such as nutrition express, fruit milk, wahaha calcium milk, etc.) and yogurt drinks (such as sour milk) , Yogurt, etc.), they are beverages rather than milk, and the protein content is more than 1%. The nutritional value is not the same as that of milk. It is not a milk recommended by the dietary guidelines and cannot replace milk.