In Traditional Chinese Medicine, it is believed that the body maintains its health and vitality through the rise and flourishing of Yang energy. However, frequently consuming or coming into contact with cold foods in daily life can easily deplete this Yang energy, which is extremely detrimental to the body.
As the saying goes, "calamity comes from the mouth, and illness enters through it." Improper diet is the primary factor leading to the depletion of the body's Yang energy. Yang energy is a warm and热 energy, and it is most vulnerable to cold. Any food with a cold nature will cause damage to the body's Yang energy. Therefore, health preservation and maintenance should start with protecting the body's Yang energy. Likewise, any behavior that depletes Yang energy is harmful to the body.
Now, let's look at which foods are considered cold.
1. Fruits and Vegetables: Moderation is Key
Most fruits are considered cool-natured, such as watermelon, pears, and navel oranges. Many women who are dieting often skip staple foods and rely mainly on fruits and vegetables. Over time, this can lead to various symptoms of Yang deficiency and excessive cold. In clinical practice, we often see that many dieting women experience dysmenorrhea, light menstrual flow, delayed periods, or even amenorrhea. This is because they do not consume staple grains and meats, but instead eat large quantities of fruits and vegetables. As a result, not only do they fail to replenish Yang energy from grains and meats, but the excessive fruits and vegetables continuously deplete it, eventually leading to Yang deficiency and excessive cold. This cold evil lodges in the uterus, causing "uterine cold" and a series of menstrual disorders. Therefore, the more fruit you eat, the healthier it is not. Fruit consumption should be moderated: eat in moderation, for example, one piece of fruit per day like an apple or pear is sufficient. Also, avoid eating on an empty stomach; it's best to eat after a meal.
2. Green Tea: Drink in Moderation
Next is green tea. Although both are types of tea, black tea is warm-natured, while green tea is cool-natured. Green tea has the effect of clearing heat and reducing fire. Strictly speaking, moderate consumption can indeed make the upper part of the body, such as the throat, mouth, and head, feel refreshed and comfortable. But the problem with anything is excess. The *Neijing* (Inner Canon of Huangdi) says, "Disease arises from excessive use." Even the best things can cause harm if used excessively. Green tea is a cool-natured product. Drinking too much of it—for instance, some people hold onto a teapot all day, drinking several thermoses of tea—will deplete the body's Yang energy, leading to its deficiency. This way of drinking tea is more harmful than beneficial to health.
It is also important to note that tea should not be consumed on an empty stomach. Drinking tea on an empty stomach allows its cold nature to directly attack the lower energizer, damaging the true Yang. Many people experience palpitations and dizziness after drinking tea on an empty stomach, which is a manifestation of Yang deficiency with water泛滥 (water泛滥 is a specific TCM term, can be translated as "water泛滥" or explained as "water overflowing").
The correct way to drink tea is to have 3 to 5 cups after a meal. This aids digestion, clears heat, and does not harm the body.
3. Cold Drinks: Best to Avoid Them
First, there are cold drinks. In the summer, many people drink large amounts of cold drinks to beat the heat. Men might drink lots of iced beer, while women might crave ice cream and iced beverages. It's also a common habit for many to eat iced watermelon. After these cold elements enter the body, the body has to expend a great deal of Yang energy to counteract the damage they cause. Thus, the body's Yang energy is continuously depleted. From this perspective, the invention of the refrigerator is a technological advancement that does more harm than good.
4. The Misconception of a Glass of Cool Water in the Morning
I don't know when it started, but at least for the past 20 years, this health regimen has been popular: a glass of cool boiled water in the morning can regulate endocrine function and also aid in bowel movements. For a time, everyone followed suit, and many people drank cool boiled water upon waking. However, according to clinical surveys, many people who drink cool water in the morning gradually develop symptoms of Yang deficiency after a few months or half a year. Women may experience dysmenorrhea, delayed periods, or even amenorrhea, while men may suffer from stomach problems, joint pain, decreased sexual function, and others may develop allergic rhinitis or other lingering, hard-to-cure illnesses. This is because drinking cool water directly on an empty stomach in the morning severely damages the Yang energy of the lower energizer. This so-called health habit is actually quite harmful.
I had a patient, a 32-year-old man, who came to see me for allergic rhinitis. It was September, just the beginning of autumn. Every morning, he would have a runny nose and constant sneezing, accompanied by itchy and watery eyes, and he was especially sensitive to any breeze. At just 30 years old, he was already experiencing severe hair loss, with sparse hair on the top of his head, saying he lost over a hundred hairs a day. He also had symptoms of decreased sexual function. These issues had appeared for 2 years and were progressively worsening. I prescribed him medication to warmly tonify his Yang energy. After 6 doses, the eye itching, tearing, and rhinitis all disappeared. Feeling the significant effect, he continued to take the medicine from me. Later, he asked a question, saying, "My health was originally very good. You can see my work isn't too strenuous. Also, I don't smoke or drink, and I don't overindulge in sexual activity. How could my health have declined so severely in these two years?" I carefully inquired about his lifestyle habits. No drinking, no love for cold foods, no excessive sexual activity. Finally, when I couldn't find a reason, I told him to pay attention to his diet: no cold drinks, not too much fruit, and not too much cool water. He accepted this. As he was leaving the consultation room, he suddenly turned around and asked, "Can I still drink that glass of cold water in the morning?" I said, "You still drink cold water in the morning?" He said, "Yes, for 3 years. Isn't that supposed to be 'life water'?" Oh! I had finally found the reason for his depleted Yang energy.
By now, you should basically understand. Drinking cool boiled water on an empty stomach in the morning also allows the cold nature to directly attack the lower energizer, damaging the Yang energy, and is therefore detrimental to health.
5. Seafood: Eat in Moderation
Among foods and drinks, besides directly cold items like cold drinks, there are many foods and beverages that do not feel cold in temperature but are classified in Traditional Chinese Medicine as having a cold nature, such as seafood. Among seafood products, only a very few like fish, shrimp, and abalone are warm-natured; most are cold, such as crabs, clams, and oysters. These creatures, having lived in the cold sea water for a long time, naturally develop a cold nature. Therefore, when eating seafood like crab, one must not eat too much, and it must be eaten with ginger sauce to counteract its cold nature with the warmth of the ginger. Some people experience stomach pain after eating crab, which is because the cold nature of the crab damages the stomach's Yang energy.
There was a gentleman who came to see me for a stomach condition. He felt a strong sense of blockage in his stomach, would constantly burp and have food come back up after eating, and had intermittent stomach pain. He said this problem had lasted for over 4 years. Another very important symptom was that whenever his stomach was uncomfortable, a specific tendon on the top of his foot would hurt, and this was true for both feet. I took a close look and found this was exactly along the pathway of the Foot Yangming Stomach Meridian, indicating he had classic symptoms of stomach Yang deficiency. Upon further conversation, I learned that due to his work, he often had to accompany people for meals, frequently going to seafood restaurants. He himself was a great lover of crab and also had a habit of drinking cold drinks, sometimes drinking several bottles of iced beer in one meal. Over several years, these issues developed. Therefore, I prescribed him medication to warmly tonify his stomach Yang and advised him to avoid iced drinks and crab. After 3 weeks, his stomach symptoms disappeared, and the pain in his feet never returned.