"Milk is cold in nature, and drinking it will damage the spleen and stomach for people with cold body"?

Rumor: "Milk is cold in nature. Drinking it will damage the spleen and stomach and cause diarrhea in people with cold body."

Some people on the Internet say: "Milk is cold in nature, and people with cold constitution should not drink it. Drinking it will cause stomachache and diarrhea." Many people believe this.

Rumor analysis: Not true.

Ancient people had limited knowledge of the specific digestion process of food in the human body. From an empirical perspective, they believed that "eating cold food will make your stomach uncomfortable", so they thought that "milk is cold in nature". But in fact, the so-called "milk is cold in nature" may just be a reaction to poor lactose absorption. Some people are also intolerant to A1β-casein. Just choose the product that suits you.

Milk has always been recognized as a high-quality source of nutrition, with good quality, low price and easy access. However, there are some rumors about milk on the Internet: "Milk is cold", "Milk is high in moisture", "Milk hurts the spleen and stomach", and the evidence is that many people get diarrhea after drinking milk.

But is this really the case?

The so-called "milk is cold" may just be a reaction to lactose malabsorption

The ancients had limited knowledge of the specific digestion process of food in the human body. During their observations, they found that some people often experienced symptoms of gastrointestinal discomfort such as diarrhea after drinking milk. From an empirical point of view, they believed that "eating cold things will make the stomach uncomfortable", so they thought that "milk is cold in nature".

Since the mid-20th century, scientists have begun to notice problems with lactose digestion in different populations, and they have found that lactase activity varies between individuals and between different age groups.

Specifically, the human body needs to rely on lactase to break down lactose, but for many adults, the activity of lactase decreases with age. When lactase activity is insufficient, the unbroken lactose will directly enter the large intestine, where it will be fermented by intestinal bacteria to produce gases (such as hydrogen), lactic acid and other substances. The accumulation of these substances can lead to a series of uncomfortable symptoms, including bloating, abdominal pain, diarrhea, increased flatulence, etc. This is what is now commonly referred to as "lactose intolerance."

In fact, to be more precise, most people suffer from lactose malabsorption.

Copyrighted stock images, no reproduction is authorized

Statistics show that about 68% of people in the world have lactose malabsorption, but the proportion is relatively higher in East Asia. However, this does not mean that Chinese people are not suitable for drinking milk. This is mainly because milk was popularized relatively late in my country, and many people have not developed the habit of drinking milk since childhood. On the one hand, the body does not retain enough lactase, and on the other hand, the tolerance of the intestine is relatively low. Once drinking, they feel uncomfortable, and their favorability for milk is inevitably reduced.

Some studies have shown that for some individuals, gradually increasing the intake of milk or other lactose-derived foods can improve their lactose tolerance, a phenomenon known as "induction of lactose tolerance." However, this does not work for everyone.

Feeling uncomfortable after drinking milk may also be caused by A1β-casein intolerance

On the other hand, if some people still experience gastrointestinal discomfort after drinking lactose-free milk, it may be related to A1 β-casein intolerance.

In 2017, a clinical study involving 600 subjects in China who self-diagnosed themselves as lactose intolerant showed that some people's milk-related gastrointestinal symptoms may originate from A1β-casein rather than lactose.

In addition, some children may have milk protein allergy. According to UTD data, nearly 2% of children under 4 years old may have milk protein allergy. However, as they grow older, most children's milk protein allergies can be relieved spontaneously.

Some people also recommend boiling milk at high temperature in order to solve the problem of milk's "cold nature" from a physical perspective. But in fact, the milk commonly sold in supermarkets has been sterilized at high temperatures. As for people with lactose malabsorption, whether the milk is boiled at high temperatures or not, the lactose content in it will not be reduced, and you may still have diarrhea after drinking it. Boiling milk at high temperatures may lead to the loss of some nutrients (such as vitamins), and the lactose in the milk may produce a slight caramelization reaction at high temperatures, affecting the taste and color of the milk.

Drinking milk is more recommended

According to the recommendations of the "Dietary Guidelines for Chinese Residents (2022)", in general, adults consume 300 to 500 grams of milk and dairy products per day. For people with lactose malabsorption, first avoid drinking milk on an empty stomach. Then, you can try to "control the single milk intake and increase the frequency of milk intake", such as drinking 250 ml a day, but drinking continuously without interruption, to see if you can "desensitize". If it doesn't work, you can also choose lactose-free milk that has been lactose-decomposed or milk with lactase pre-added. Drinking fermented dairy products such as yogurt is also a good choice.

For people who are intolerant to A1β-casein, in recent years, A2β-casein milk and yogurt labeled as A1β-casein-free have also been sold, so just be careful when buying. If you are both lactose intolerant and A1β-casein intolerant, you should also pay attention to the choice of variety, intake, intake time and frequency.

Copyrighted stock images, no reproduction is authorized

Finally, what you really need to be careful about when drinking milk is not to take it with the following types of medicines:

1. Gastric mucosal protective agents and antacids

Taking medicines containing metal ions such as aluminum hydroxide, magnesium hydroxide, and calcium carbonate together with milk may reduce the efficacy of the medicine and affect the absorption of nutrients in milk.

2. Antibacterial drugs

Eating antibiotics such as norfloxacin, levofloxacin, ciprofloxacin, etc. with milk may reduce the efficacy of the drugs.

3. Drugs for the treatment of cardiovascular diseases

Certain drugs for treating cardiovascular disease may interact with calcium, protein or other components in milk, affecting the absorption, metabolism or effectiveness of the drugs.

Looking in the mirror of rumors

The belief that certain foods are "cold" is mainly based on the "experience" that the ancients observed and summarized from some life phenomena. However, due to the limited level of scientific development at that time, people had limited understanding of the structure and working principles of the human body, and this empirical evidence was not necessarily accurate. For example, the belief that "milk is cold and will cause diarrhea" is related to the lactase activity in different human bodies through modern scientific research.

Author: Likely Popular Science Creator

Review｜Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center

Liu Ziqi, Chief Pharmacist, The First Affiliated Hospital of Harbin Medical University