Author: Fan Zhihong
Associate Professor, Department of Nutrition and Food Safety, College of Food Science, China Agricultural University, Ph.D. in Food Science
Director of Chinese Nutrition Society, senior member of China Food Science and Technology Association, director of Beijing Popular Science Writers Association and other positions.
The main teaching and research directions are the impact of cooking and processing on the nutritional and health value of food, the design and development of nutritious food and nutritional recipes, and the impact of health factors on food selection, etc., and he is the chief editor and co-editor of 11 textbooks and published 116 papers.
Source: Fan Zhihong – Original nutritional information
It has been authorized to be reprinted by China Clinical Nutrition Network
Milk and soy milk, which look like milky white liquids, are breakfast food choices on the table, and they are also known as nutritious.
The Dietary Guidelines for Chinese Residents 2022 recommend drinking 300-500 ml of milk per day, while also consuming soy products equivalent to 25 grams of soybeans, including soy milk. 1 cup (250 grams) of traditional soy milk is about the equivalent of 12.5 grams of soybeans (1 serving of soybeans + 20 times the amount of water beaten soy milk, not too thick).
However, many people will be entangled, the appetite at breakfast is so big, soy milk and milk each cup is of course excellent, helpless concubines really can't drink ah...
Besides, both drinks have their own fans and opposition.
Proponents of milk say: milk is more comprehensive than soy milk! Milk can supplement calcium, soy milk cannot!
Proponents of soy milk say: soy milk is more suitable for Chinese stomach than milk! Soy milk is good for disease prevention, milk is useless!
Some people say: soy milk is not suitable for people with breast diseases! Some people also retorted: milk is not conducive to preventing breast cancer!
It is estimated that many people listen to these words, feel dizzy enough, and do not know how to choose.
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In fact, this may be caused by insufficient understanding of milk and soy milk. Are you suitable for drinking soy milk, or is it suitable for drinking milk? Knowing the difference means knowing what to choose. Regarding the comparison of the characteristics of soy milk and milk, it is estimated that this is the most comprehensive explanation you will ever find.
Let's start with what they have in common.
The similarities between milk and soy milk are actually much more than many people think.
- Both milk and soy milk provide protein. The protein content in milk is 2.9%~3.6%, roughly calculated by 3%; The protein content in soy milk depends on how many beans and how much water are added, ranging from 1.8% to 3.6%, and take a closer look at the protein content on the food label. Of course, if concentrated a bit, both can make a higher protein content.
- Both milk and soy milk provide fat. The fat in milk is cream, and the fat in soy milk is soybean oil. After these fats are emulsified by proteins and phospholipids, they form tiny fat microspheres that are suspended in the aqueous phase and scatter light, and as a result, they look like milky white liquid.
- Both milk and soy milk provide a lot of potassium. Don't think that milk only has calcium and no potassium, in fact, the potassium content is higher than the calcium content! Beans are classic high-potassium foods, so soy milk has a lot of potassium. According to the "China Food Composition Table (Standard Edition)", 100 grams of soy milk with 3.0% protein content contains 117 mg of potassium, while 100 grams of milk with 3.3% protein content contains 188 mg of potassium. So, for people with high blood pressure, both are good drinks.
- Both milk and soy milk contain a variety of B vitamins, vitamin E and vitamin K. Whole milk contains vitamin E and vitamin K, and skim milk contains very little. But skim milk still contains 8 B vitamins. Soy milk inherits the advantages of soybeans rich in vitamin E and vitamin K, and also incorporates the 7 B vitamins in soybeans.
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——Both milk and soy milk have a good sense of satiety. The protein and fat in milk and soy milk can promote gastrointestinal hormones such as cholecystokin, GIP, and GLP-1 to increase feelings of fullness. Although they are ingested in a liquid state, after entering the stomach, under the action of gastric acid, they will become clots, and the gastric emptying time is much longer than that of white porridge and sweet drinks with the same calorie value, so the satiety effect is more durable.
- Drinking milk and drinking soy milk will help suppress the rise of blood sugar after meals. Some literature has found that drinking milk or soy milk at the same time when eating white bread can reduce the postprandial blood sugar response. However, if you drink milk or soy milk 30 minutes before the meal and then eat bread, the effect will be even more remarkable. In the case of the same protein content, the blood sugar control effect of milk and soy milk is not much different.
- Milk and soy milk are both drinks with a low glycemic index, but both stimulate insulin production. Many people have heard that milk has a low glycemic index but a high insulin index. In fact, almost all high-protein foods can stimulate insulin by increasing the gastrointestinal hormones GIP and GLP-1, which is not exclusive to milk. Soy milk is also a source of protein, and soy protein also has this effect.
- Both milk and soy milk promote muscle gain. Whey protein, casein in milk, and soy protein in soy milk can all play a role in promoting muscle gain. Drinking a glass of milk or soy milk in time after exercise is beneficial to muscle synthesis. In terms of effect, milk protein is slightly better because it is rich in leucine, but some studies have compared the two and found that whey protein and soy protein have a muscle gain effect of only 20%.
——Milk and soy milk are prone to flatulence, and the principle of flatulence is also similar.
The cause of milk flatulence is lactose in it, and people with insufficient lactase secretion cannot fully digest it, and undigested lactose entering the large intestine can cause problems such as intestinal gas production, bowel sound, bloating, diarrhea, etc.
The cause of soy milk flatulence is the oligosaccharides contained in it, including raffinose, stachyse, verbasse, etc., which cannot be digested and absorbed by the human small intestine, and will also cause discomfort after entering the large intestine.
However, for people with normal digestive ability, in the case of small intake, lactose and these oligosaccharides are beneficial factors for the proliferation of beneficial bacteria in the intestines, and are also conducive to the absorption and utilization of a variety of minerals in food.
- Both milk and soy milk can help hydrate. Although milk and soy milk contain a variety of solutes, they have a moisture content of up to more than 87%. Pure water will be absorbed and utilized within about 20 minutes, but water with solute is absorbed slowly in the body. As the nutrients in milk and soy milk are gradually absorbed and utilized, water is slowly absorbed and utilized.
Studies have found that compared with drinking the same amount of water, after drinking milk, water stays in the body longer, which is the truth. Of course, this is talking about unsweetened milk and soy milk. Adding sugar increases osmotic pressure and reduces their hydrating effect.
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Let's talk about their differences.
- Vitamin AD and vitamin B12 are in milk, not in soy milk. This is because plant foods do not contain these vitamins. Soy milk contains a small amount of carotene, but it is still too small in terms of the amount converted into vitamin A.
——There is a lot of calcium in milk, and very little calcium in soy milk. Milk is the easiest natural food for calcium to use, with more than 100 mg of calcium per 100 grams of milk.
Although there is also a lot of calcium in soybeans, the content drops greatly after dilution with water. If the calcium content in 100 grams of soybeans is 200 mg, according to the traditional soy milk 1 kilogram of beans plus 20 kilograms of water, the calcium content per 100 grams of soy milk is about 10 mg. If it is made into thick soy milk, it is about 20 mg. Some soy milk contains only a few mg/100 g of calcium. Therefore, soy milk can not replace the calcium supplement effect of milk, and other plant milk can not, unless a lot of well-absorbed calcium is added.
——The proportion of saturated fat in milk is large, and the proportion in soy milk is very small. The fat in milk is cream, which contains about 40%~50% saturated fat, and most of the rest are monounsaturated fatty acids (the most fatty acids in olive oil). The fat in soy milk is soybean oil, of which more than 80% is unsaturated fatty acids, and saturated fatty acids account for only more than ten percent. Therefore, if you follow your doctor's advice to control saturated fatty acids, you can choose low-fat milk or skim milk, or choose soy milk.
——There are oligosaccharides and dietary fiber in soy milk, but not in milk. Dietary fiber is only found in plant-based foods (with the exception of shrimp and crab shells). There are also oligosaccharides in milk, but the content in milk is relatively low enough to produce effective health effects. Breast milk is rich in human milk oligosaccharides, which are an important part of the health effects of human milk and are extremely beneficial to the baby's intestinal health. More oligosaccharides in soy milk will produce flatulence, but when ingested in small amounts, it is beneficial to the intestinal health of most people.
——There are many antinutrients in soy milk, but not in milk. Soy milk contains antinutrients such as trypsin inhibitors, lectins, phytic acid, oxalic acid, saponins, etc., which can reduce the absorption and utilization efficiency of protein and a variety of minerals. Among them, phytic acid, oxalic acid and saponins are still retained after heating, but because some of them will combine with proteins, polysaccharides and other components, their biological effects on digestion and absorption are reduced. Lectin and trypsin inhibitors are mostly destroyed after heating. According to our actual measurements and relevant literature data in Japan,
Commercially available soy milk and soy milk made from household soy milk machines, in which trypsin inhibitor activity still has about 13% residue. Prolonged heating can further destroy trypsin inhibitors, but they contain heat-resistant components that retain about 5% of their activity even after prolonged heating.
Trypsin inhibitors are components that inhibit the proliferation of cancer cells, and a small amount of residual activity is beneficial to health in healthy people.
- Soy milk has soy isoflavones, milk does not. Everyone knows that soy isoflavones in soy milk are a kind of phytoestrogen, in the case of menopausal estrogen deficiency, supplementation of phytoestrogens is beneficial to reduce the discomfort of menopausal syndrome, and at the same time is conducive to the prevention of osteoporosis in middle-aged and elderly women. For men, epidemiological studies have found that the intake of soy isoflavones is beneficial in preventing prostate cancer in men. There is currently no evidence that Asian women's intake of normal amounts of soy milk and soy products increases breast cancer risk.
——Some people drink milk and will have acne on their faces, but soy milk will not. Components such as IGF-1 in milk promote sebum secretion and increase the risk of acne worsening. In this regard, switching to skimmed, lactose-free milk is no better than regular whole milk. Soy milk has no effect on promoting sebum secretion.
——Some people drink soy milk will affect the menstrual cycle or premenstrual feeling, milk will not. For women of childbearing age who have not often drunk soy milk before, after suddenly drinking more soy milk every day, the phytoestrogens in it may temporarily affect the menstrual cycle, but after forming a new cycle, it does not affect health. Reactions to soy milk vary from person to person, with people who regularly consume soy products from childhood having little reaction, while people who have rarely been exposed to soy products before may be more sensitive.
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——People with high uric acid drink milk is conducive to reducing uric acid and preventing gout, soy milk cannot. Milk is a food with very low purine content, and the potassium, calcium, orotic acid and other components in it are beneficial to reduce uric acid levels. Therefore, patients with gout are suitable to drink milk every day during the attack and remission period. Soybeans are medium and high purine foods, although the content decreases after beating into soy milk, but because soy milk is a cup or bowl, the total amount of purines can still not be ignored. At the same time, components such as phytic acid and oxalic acid in soy milk will also affect the excretion of uric acid.
Some scholars in the mainland have done experiments that ingesting soy milk will cause a temporary rise in blood uric acid levels, but it will return to normal after 3~4 hours. Epidemiological investigations have shown that normal intake of soy milk and soy products in healthy people does not increase the risk of uric acid, but people who already suffer from gout or hyperuricemia are not recommended to drink large amounts of soy milk.
- People with different allergies to milk and soy. Milk and soy are both common food allergens. Acute allergy to cow's milk is usually found in infants under 2 years of age and, to a lesser extent, adults. But in adulthood, chronic allergies to cow's milk are still common. It is also not uncommon for adults with soy allergies to be available. Food allergy or intolerance testing is required to go to the allergy department of a tertiary hospital, and these problems can often be detected. Doing food elimination experiments one by one can also find out the chronic allergens of foods that cause you various discomforts. However, some people are allergic only to cow's milk or only to soy. For example, I did a test 3 years ago and the results showed that I had no allergy to milk at that time, but had a grade 3 chronic allergy to soybeans, including yellow, black and green soybeans.
What do you think? Seeing this, it is estimated that most friends have come to their own conclusions about whether it is suitable to drink milk or soy milk, or both.
Finally, to summarize:
Soy milk and milk are both drinks with good nutritional value, and if there are no adverse reactions, it is worth drinking frequently. Most people fit both. A glass of milk in the morning, a glass of soy milk in the evening, or a glass of soy milk in the morning, a glass of milk in the evening, according to your wishes.
People who need to control blood sugar, drinking a glass of milk or soy milk when eating starchy foods, or before, is beneficial to control the postprandial blood sugar response.
People who lose weight use milk or soy milk instead of sweet drinks and cold drinks, which not only increases nutrition, but also helps prevent fertilization. Under the same protein content, milk is more recommended, because calcium deficiency is more likely to occur obesity, and weight loss is also prone to lack of multivitamins.
Both pregnant and nursing mothers can drink it, but milk is more important because it can supplement the large amount of calcium needed during pregnancy and breastfeeding.
Menopausal women can drink both, milk increases calcium intake, and soy milk increases soy isoflavone supply. Taken together, it is better for bone health.
A few people need to choose one or the other.
For example, those who drink milk and are prone to acne are suitable for drinking soy milk instead, and at the same time can supplement a calcium tablet containing 200~300 mg of calcium. For example, gout patients are more suitable for drinking milk, especially during gout attacks, fish, meat, seafood river fresh, soy milk, tofu are temporarily not suitable for eating, but you can safely drink two or three cups of skim milk to help supply high-quality protein, calcium and water.
There are also some people who may not be suitable for both.
For example, people who are allergic to both milk and soy should not drink both. Some people with thyroid disease and irritable bowel can also temporarily refrain from drinking milk and legumes if advised by a doctor.
In addition, people who have poor digestion and are prone to bloating should also pay attention to drinking less, after all, both contain ingredients that may cause flatulence. However, this does not hinder the nutrition of milk and soy, because you can also drink yogurt, eat cheese to replace milk, or eat tofu, dried tofu to replace soy milk. If you eat a small amount and many times, it is not easy to have an uncomfortable reaction.
There are also some friends who have no physiological taboos to both milk and soy milk, but they don't like the flavor of one or the other. Here's a suggestion by the way: milk soy milk mixed drinking, have you tried it? It not only dilutes the soy milk flavor, but also masks the smell of milk, and the flavor is better and worth tasting! If you add a little honey and salt, you can replenish energy, protein and hydration at the same time, and replace various sweet drinks and sports drinks after summer exercise, which is very good for restoring physical strength and increasing muscle.