There is currently controversy about the best time to drink milk.
According to research by medical experts in the US and UK, milk contains two previously unknown hypnotic substances. One is tryptophan, which promotes sleep by synthesizing serotonin, and its effect can often induce sleep after just one glass. The other is a natural morphine-like substance with anesthetic and sedative effects. Therefore, drinking milk in the morning will inevitably inhibit the cerebral cortex, affecting daytime work and study. Additionally, drinking milk on an empty stomach in the morning is not conducive to digestion and absorption. This is because milk's protein must be broken down by the stomach and small intestine into amino acids before it can be absorbed. In the morning, on an empty stomach, the stomach and intestines empty quickly, so the milk is excreted to the large intestine before it can be digested. Therefore, nutrition experts believe that milk is best consumed in the evening or half an hour before bedtime.
However, recently many professionals have pointed out that drinking milk at night can easily lead to "internal heat" (a concept in traditional Chinese medicine), which is actually detrimental to sleep. Instead, they advocate drinking milk in the morning.
Therefore, the issue is still somewhat controversial, and the time to drink milk should be determined based on your own situation and the personal effects you experience after consuming it.
Scientific Consumption
1. Do not drink raw milk. Fresh milk should be heated to a high temperature to prevent illness.
2. 80% of the protein in milk is casein. When the pH of milk is below 4.6, a large amount of casein will coagulate and precipitate, making it difficult to digest and absorb. In severe cases, it may lead to indigestion or diarrhea. Therefore, acidic beverages like juice should not be added to milk.
3. Some people like to use milk instead of plain water to take medicine. In fact, milk significantly affects the body's absorption of drugs. Milk can easily form a coating on the surface of the drug, causing calcium, magnesium, and other minerals in the milk to react chemically with the drug to form insoluble substances, thereby affecting the release and absorption of the drug's efficacy. Do not drink milk one hour before or after taking medication.
4. It is not advisable to drink cold milk, as cold milk can affect gastrointestinal motility, causing mild diarrhea and preventing most of the nutrients in the milk from being absorbed and utilized by the body.
5. It is not advisable to heat milk at high temperatures for a long time. The protein in milk, under high temperature, will change from a sol state to a gel state, leading to precipitation and a decrease in nutritional value.
6. Milk and (dark) chocolate should not be eaten together for two reasons:
First, the components in chocolate can destroy the calcium in milk, preventing its absorption. This means some of the nutrients in milk cannot be ingested; in other words, part of the milk is drunk for nothing.
Second, the components in milk can affect the beneficial effects of chocolate's components, such as its antioxidant and anti-thrombotic properties, which cannot be expressed when milk is present.
Common Misconceptions About Drinking Milk
01. Milk must be boiled: The temperature required to pasteurize milk is not high. 3 minutes at 70°C or 6 minutes at 60°C is sufficient. If boiled, the temperature reaches 100°C, causing the lactose in the milk to caramelize, and caramel can induce cancer. After boiling, calcium in the milk will precipitate as calcium phosphate, reducing its nutritional value.
02. The thicker the milk, the better: So-called "thick milk" refers to adding too much milk powder and too little water, making the concentration exceed the normal standard. Some parents add milk powder to fresh milk, fearing it is too dilute. The concentration of milk for infants and young children should be proportional to their age, increasing gradually with each month. If infants and young children often drink overly concentrated milk, it can cause diarrhea, constipation, loss of appetite, or even refusal to eat. Over time, it can lead to acute hemorrhagic enteritis.
03. The more sugar added, the better: Sugar is added to increase the calories supplied by carbohydrates, and the amount must be controlled. Generally, 5-8 grams of sugar are added per 100 ml of milk. Too much sugar in a baby's body can cause water retention, making muscles and subcutaneous tissue soft and weak, leading to a chubby appearance but poor physical resistance, and it can become a risk factor for some diseases.
Sucrose is the best type of sugar to add to milk. After entering the digestive tract, sucrose is broken down by digestive juices into glucose, which is absorbed by the body.
There is no need for parents to specially buy glucose for their children. Glucose has a low sweetness, and using too much can easily exceed the recommended amount, and children may refuse to drink it because it's not sweet enough.
Heating sugar and milk together can cause lysine in the milk to react with the sugar at high temperatures (80°C-100°C), forming a harmful substance called glycosylated lysine, which is very dangerous for children. Therefore, you should first let the boiled milk cool to lukewarm (40°C-50°C) before adding the sugar to dissolve it.
04. Avoid taking medicine with milk
Milk can significantly affect the speed at which the body absorbs drugs and can easily form a coating on the drug's surface. Calcium, magnesium, and other mineral ions in the milk can react with the drug to form insoluble substances, which not only reduces the drug's efficacy but may also harm the body. Therefore, it is best not to drink milk one to two hours before or after taking medication.
05. Feeding babies with yogurt: The antibiotics produced by lactic acid bacteria in yogurt, while inhibiting the growth of many pathogens, also destroy the conditions for the growth of beneficial normal flora in the body and can affect normal digestive function. For infants with gastroenteritis or premature babies, feeding them yogurt may cause vomiting and necrotizing enteritis.
06. Adding orange or lemon juice to enhance flavor: Orange and lemon are both high in fruit acid. When fruit acid encounters the protein in milk, it can denature the protein, reducing its nutritional value.
07. Adding rice congee or porridge to milk: Milk contains vitamin A, while rice congee and porridge are mainly starch-based. They contain lipoxidase, which can destroy vitamin A. Children, especially infants, who do not get enough vitamin A may experience delayed development and become weak and sickly.
Using condensed milk instead of fresh milk: Condensed milk is too sweet and must be diluted with 5-8 times its volume of water. When the sweetness is acceptable, the concentration of protein and fat is half that of fresh milk, which cannot meet the growth and development needs of a baby. If the amount of water is adjusted so that the protein and fat concentration is close to fresh milk, the sugar content becomes too high, which can easily cause diarrhea in children and make it difficult to add complementary foods later.
Harmful Ways to Drink Milk
Milk with chocolate
Some people think that since milk is a high-protein food and chocolate is an energy food, eating them together must be very beneficial. This is not the case. Liquid milk combined with chocolate causes the calcium in the milk to react with the oxalic acid in chocolate to form "calcium oxalate." Thus, the originally nutritious calcium becomes a harmful substance, leading to calcium deficiency, diarrhea, delayed development in children and adolescents, dry hair, easy fractures, and an increased incidence of urinary tract stones.
Taking medicine with milk for two benefits at once
Some believe that taking medicine with something nutritious is beneficial, but this is extremely wrong. Milk can significantly affect the speed at which the body absorbs drugs, causing the drug concentration in the blood to be significantly lower than in those who take it without milk, over the same period. Taking medicine with milk can also easily form a coating on the drug's surface, causing calcium, magnesium, and other mineral ions in the milk to react with the drug to form insoluble substances. This not only reduces the drug's efficacy but may also harm the body. Therefore, it is best not to drink milk one to two hours before or after taking medication.
Adding rice congee or porridge to milk
Some people think this can complement the nutrients. In fact, this practice is very unscientific. Milk contains vitamin A, while rice congee and porridge are mainly starch-based and contain lipoxidase, which can destroy vitamin A. Children, especially infants, who do not get enough vitamin A may experience delayed development and become weak and sickly. Therefore, even for nutritional supplementation, the two should be eaten separately.
Milk must be boiled
Usually, the temperature required to pasteurize milk is not high. 3 minutes at 70°C or 6 minutes at 60°C is sufficient. If boiled, the temperature reaches 100°C, causing the lactose in the milk to caramelize, and caramel can induce cancer. Secondly, after boiling, calcium in the milk will precipitate as calcium phosphate, reducing its nutritional value.
Placing bottled milk in the sun to increase vitamin D
Some people learned from advertisements that to supplement calcium, you also need vitamin D, and that getting more sun is a good way to get it. So they placed bottled milk in the sun. In fact, this is not worth it. The milk may gain some vitamin D, but it loses vitamin B1, vitamin B2, and vitamin C. These three nutrients can decompose in sunlight, causing them to be partially or completely lost. Moreover, the lactose in the milk can ferment in the sun, causing it to spoil.