How to maintain health during the Grain in Ear season? A Traditional Chinese Medicine guide to diet and lifestyle for strengthening the spleen, removing dampness, clearing heat, and relieving summer heat.

Every year in the Gregorian calendarBetween June 5th and 7th, the sun reaches 75° ecliptic longitude.This time, "Grain in Ear" (芒种), is the third solar term of summer in the 24 solar terms, marking the official start of typical hot and humid weather (China Meteorological Administration). Hong Kong summers are both hot and humid. Traditional Chinese medicine believes that this climate easily leads to "summer dampness trapping the spleen," affecting the spleen and stomach's digestive function. Therefore, the focus of dietary adjustments at this time is..."Strengthening the spleen and removing dampness" and "Clearing heat and relieving summer heat"Two main directions.

The following is a summary of key points for diet and lifestyle before and after the Grain in Ear solar term: which foods are suitable, what to pay attention to with seasonal fruits (mango, lychee), and the characteristics of common summer fruits.The difference and preparation methods of mung bean water and mung bean soupThis article also covers topics such as how to sleep in the summer. All Traditional Chinese Medicine (TCM) content is clearly labeled as part of TCM theoretical frameworks, and verifiable official sources and modern research are provided to aid your own judgment.

What is Grain in Ear (芒种)? Its characteristics and physical changes.

"Grain in Ear" (芒种) is the ninth of the twenty-four solar terms and the third solar term of summer. Its name means "wheat with awns is ready for harvest, and rice with awns can be planted," hence it's also called "busy planting" (忙种). It marks the peak of the "Three Summers" (三夏) busy season in agriculture, encompassing summer harvest, summer planting, and summer management. Climatically, around Grain in Ear, southern China enters the plum rain season, characterized by abundant rainfall, significantly higher temperatures, and increased humidity. Most parts of the country experience this season.High temperature and high humidity coexist(China Meteorological Administration).

Hong Kong's lower latitude means that summer heat and humidity arrive earlier. Traditional Chinese medicine believes that people are prone to fatigue and loss of appetite during this time; skin and gastrointestinal problems are also more common. Clinical observations by Wu Mingzhu, a TCM practitioner in Taiwan, indicate a significant increase in patients seeking treatment for skin symptoms during this period, commonly including excessive facial oiliness, recurring acne, and atopic dermatitis flare-ups after sweating; cases of heatstroke have also increased, often accompanied by stiff neck and shoulders, nausea, and diarrhea (this is based on clinical observation, not research data).

From a modern perspective, these phenomena all have a real physiological basis:High temperatures increase sweating, leading to the loss of water and electrolytes (such as potassium and sodium); hot and humid conditions affect sleep quality and appetite; prolonged sun exposure and high temperatures increase the risk of heatstroke (heat exhaustion).Therefore, the adjustment of diet and lifestyle in summer is essentially to replenish water and potassium, maintain appetite, and reduce the burden on the body in terms of heat dissipation.

How does Traditional Chinese Medicine view "dampness" and "heat" in summer?

First, let me clarify: the following belong toTheoretical framework of Traditional Chinese MedicineThe concepts of "dampness" and "heat" in traditional Chinese medicine are concepts within a theoretical system, and are not the same as the edema, dehydration, and electrolyte imbalance in Western medicine. The two cannot be directly converted into each other.

The Chinese Medicine Department of the Hong Kong Department of Health, in its report "Traditional Chinese Medicine Health Preservation in Four Seasons—Summer Heat Prevention," points out:"The hot summer climate can easily damage the body's vital energy and fluids. Hong Kong's hot and humid summer climate can easily lead to dampness and heat affecting the spleen and stomach. Therefore, preventing heatstroke is an important way to maintain health in summer."The document also mentions that summer heat depletes qi and damages body fluids, or that summer dampness can impair the spleen and affect appetite. Therefore, summer diets should be light, soft, and easy to digest.

Within the framework of Traditional Chinese Medicine, the characteristics of summer climate can be summarized in three points:Summer heat is a yang evil, characterized by its heat; summer heat has an ascending and dispersing nature, easily damaging body fluids and depleting qi; summer heat is often accompanied by dampness.The characteristics of "dampness" are heaviness, turbidity, and stickiness, which easily "strangle the spleen"—in traditional Chinese medicine, the spleen is responsible for transporting and transforming fluids. Once it is strained, symptoms such as fatigue, abdominal distension, poor appetite, and loose stools will appear.

To put it more objectively: the concept of "dampness" in Traditional Chinese Medicine (TCM) lacks a corresponding quantitative indicator in modern medicine (for example, there is no test called a "dampness index"). However, it corresponds to everyday phenomena—In summer, appetite decreases, body feels heavy and tired, and the stomach is prone to discomfort.—It is true, and in terms of coping methods, the two systems actually have a lot in common: eat light and easily digestible foods, eat more fruits and vegetables with high water content, eat less greasy and fried foods, and avoid eating large amounts of cold foods at once. These suggestions are valid from any perspective.

How to eat to strengthen the spleen and remove dampness: ingredients and principles

The recommendations from the Department of Traditional Chinese Medicine Affairs of the Department of Health can be summarized into several principles:A light, soft, and easily digestible diet is recommended; avoid fatty, fried, and spicy foods; choose foods that clear heat, relieve summer heat, replenish qi and promote body fluid production, and invigorate the spleen and stimulate appetite.It also advises eating more foods that promote urination and bowel movements to help the body eliminate excess water. The document further reminds people to develop the habit of drinking plenty of water during the hot summer months, and to quench thirst with warm water, while limiting cold drinks.

Traditional Chinese medicine commonly uses foods that strengthen the spleen and remove dampness, including:

• Legumes: Mung beans, red beans, lentils, Job's tears (coix seed)
• VegetablesWinter melon, loofah, lotus leaf, Chinese yam (yam)
• otherLotus seeds, millet silk, water chestnuts, figs, and jujubes

From a nutritional perspective, these ingredients share common characteristics:It has a high water content, low calories, and contains potassium and dietary fiber.In summer, we sweat a lot, and potassium is lost through sweat. Eating more of these foods can help replenish potassium; dietary fiber also helps with bowel movements. In other words, even without considering traditional Chinese medicine theory, this dietary approach is reasonable.

What we need to be careful about is the "cold" aspect. Traditional Chinese medicine believes that mung beans, winter melon, bitter melon, etc., are of a cooling nature.People with weak spleen and stomach or insufficient yang energy should not consume large quantities at once.To avoid gastrointestinal discomfort or even diarrhea, it's advisable to consume these foods in moderation if you are prone to cold hands and feet, poor appetite, or diarrhea after eating raw or cold foods. Ideally, these foods should be cooked with rice or milder ingredients.

How to choose seasonal fruits: Pay attention to the weight of mangoes and lychees.

Seasonal fruits have always been a common choice for seasonal health maintenance. Mangoes and lychees are both fruits that are abundant in early summer. They are high in water content and rich in vitamin C, making them excellent fruit choices.It's quite sweet, so portion control is recommended, especially for people with inflamed skin.The following figures are calculated per 100 grams according to the USDA FoodData Central:

• mango(FDC ID 169910): Approximately 60 kcal of energy, approximately 83.5 g of water, approximately 15 g of carbohydrates (including approximately 13 g of sugar), 1.6 g of dietary fiber, 168 mg of potassium, 36.4 mg of vitamin C, 54 mcg of vitamin A (RAE), and 43 mcg of folic acid.
• litchi(FDC ID 169086): Approximately 66 kcal of energy, approximately 81.8 g of water, approximately 16.5 g of carbohydrates (including approximately 15 g of sugar), 1.3 g of dietary fiber, 171 mg of potassium, and 71.5 mg of vitamin C.

The advice to "eat less sweet fruit when you have skin inflammation" has corresponding directions in modern research.The relationship between dietary glycemic load and acne is currently the most well-supported finding.A study of 58 teenage boys found that...The group that followed a low glycemic index diet for 8 weeks showed improvement in facial inflammatory acne.(Reynolds et al.,Nutrients(Meixiong et al., 2010); another systematic review also indicated that high-glycemic foods and dairy products may participate in acne formation by affecting insulin, insulin-like growth factor-1 (IGF-1), and androgens (Meixiong et al., 2010).JAAD International(2022). It should be noted that these studies mostly focus on overall dietary patterns, rather than testing mangoes or lychees individually, so it is inappropriate to claim that "eating mangoes causes acne" as a necessary cause and effect.

In fact, mangoes and lychees are still fruits worth eating; the key is quantity. According to the Department of Health's "two plus three daily" recommendation, one serving of fruit is approximately equal to...Half a bowl of fruit pieces—In other words, about half a medium-sized mango or about 8 to 10 lychees would be close to one to two servings. For information on another safety risk associated with consuming large quantities of lychees on an empty stomach (lychee disease), please refer to […].Summer Heat Relief and Individuals with Hot or Cold Constitutions: Timing, Quantity, and Safety Precautions for Eating Ice〉。

Also, please noteMango allergyMangoes belong to the Anacardiaceae family. The sap from the peel and stem contains urushiol, which can cause contact dermatitis (commonly known as "mango mouth"). The treatment is to peel and cut the mango into pieces, and avoid contact between the sap and the skin around the mouth. People who are allergic to pollen, latex, cashews, or pistachios are more likely to experience cross-reactions.

Fruits and melons are excellent choices for cooling off in the summer: a list and safety tips for aloe vera.

In hot weather, fruits and melons are a good choice for summer health maintenance in Traditional Chinese Medicine (TCM) because they are both hydrating and relatively mild. Below are some common types, categorized by TCM principles of "clearing heat, promoting diuresis, and relieving summer heat," supplemented with verifiable modern information:

Ingredients	Traditional Chinese Medicine perspective (clearly marked as Traditional Chinese Medicine theory)	Modern focus
winter melon	It has a sweet taste and neutral properties, clearing heat and dampness, strengthening the spleen and replenishing fluids; the peel of the winter melon promotes urination, and the seeds of the winter melon moisten the intestines.	High in water content and low in calories, it's an ideal food for hydration in summer.
loofah	Clears heat and promotes diuresis	High in water content and low in calories; suitable for making soup.
Momordica charantia	Bitter cold and cool summer	A meta-analysis of eight randomized controlled trials involving 423 patients with type 2 diabetes indicated that bitter melon supplementation had a positive effect on blood glucose and lipid levels (Zhang et al.).Heliyon(2024)
Cucumber	Clears heat and promotes diuresis	It contains approximately 951 TP4T of water and about 15 kcal/100g of calories. Its value lies in its low calorie and high water content.
watermelon	It is cold in nature and has the effect of clearing heat and relieving summer heat (also known in Traditional Chinese Medicine as "Tian Sheng Bai Hu Tang").	Low in calories, contains lycopene and citrulline; see separate article for serving size and storage instructions (see link below).
okra	Clears heat and promotes diuresis	In a randomized, double-blind trial, 60 patients with type 2 diabetes who consumed 10 grams of okra powder daily for 8 weeks showed a significant decrease in fasting blood glucose and insulin resistance (Moradi et al.).Phytotherapy Research(2020)
Aloe vera	Clears heat and promotes bowel movement	Food safety requires special attention; see below for details.

The doctor specifically advised that people with weak spleen and stomach should not eat too much at once.

Most of the above-mentioned fruits and vegetables are cooling in nature; Traditional Chinese Medicine reminds us...People with weak spleen and stomach or insufficient yang energy should not consume large quantities at once.To avoid causing gastrointestinal discomfort. In addition, if you are prone to diarrhea, it is better to let chilled fruits and vegetables come to room temperature before eating them.

Aloe vera: Before listing it as a "health-conscious choice," understand its food safety.

Aloe vera is often used as a food to clear heat and relieve constipation, but itThese are not common fruits and vegetables that can be consumed in large quantities at will.The anthraquinone compounds in aloe vera, namely aloin (aloe glycoside/aloe-emodin), are mainly found in...Green skin and yellow latex beneath itIt can stimulate intestinal peristalsis, potentially leading to abdominal pain and diarrhea. The National Center for Complementary and Integrative Health (NCCIH) in the United States...Aloe VeraThe page states that oral aloe vera gel has a stimulating laxative effect, and overall evidence for oral aloe vera is limited.

Based on these risks, the Food and Drug Administration of the Ministry of Health and Welfare in Taiwan has imposed clear restrictions on the consumption of aloe vera:Aloe vera must be completely peeled before processing and use; the daily dosage of the product, calculated as aloin, should not exceed 10 mg; products containing aloe vera should be labeled with warnings.At the same time, a reminderWomen who are menstruating, pregnant or breastfeeding, children under 12 years old, and those with gastrointestinal discomfort, abdominal pain, or kidney disease are advised against consuming products containing aloe vera.(Especially for pregnant women, there are concerns that anthraquinone compounds may stimulate uterine contractions).

Therefore, if you want to prepare aloe vera for consumption at home, be sure to do three things:Choose only clearly edible varieties (such as Aloe vera), thoroughly peel off the outer skin and remove the yellow sap, rinse thoroughly, and strictly control the portion size.Do not pick and eat wild aloe vera of unknown origin. Pregnant women, menstruating women, young children, and people with sensitive stomachs should avoid consuming it altogether.

Mung bean water: A gentle choice for clearing heat and relieving summer heat.

When it comes to cooling off in summer, mung beans are almost the most representative ingredient. Traditional Chinese medicine believes that mung beans...It is sweet in taste, cold in nature, and non-toxic. It enters the heart and stomach meridians and its functions are to clear heat and detoxify, relieve summer heat, and promote diuresis.Blue bean skin is more effective at clearing heat and removing dampness, while mung bean flesh is more effective at strengthening the spleen. This is also why "mung bean water" and "mung bean soup" have slightly different uses in traditional Chinese medicine—the skin is used to clear heat, while the flesh is cooked until tender to promote diuresis and detoxify.

The Compendium of Materia Medica records the following about mung beans.

Many articles cite the *Compendium of Materia Medica* as stating that mung beans "can replenish vital energy and harmonize the five internal organs." However, the original text, as recorded in Li Shizhen's *Compendium of Materia Medica*, Volume 3, on grains, states:"When cooked, it reduces swelling, relieves bloating, clears heat and detoxifies... strengthens the stomach and intestines. When used as a pillow, it improves eyesight and treats headaches... replenishes vital energy, harmonizes the five internal organs, calms the mind, circulates through the twelve meridians, dispels wind, and moisturizes the skin. It is suitable for regular consumption. The broth can quench thirst."(See the original text of "Compendium of Materia Medica" on Wikisource).

Here are two common instances of citation bias that deserve attention:First, the original text reads "harmonize the five internal organs," not "harmonize the five internal organs"; second, the phrase "brighten the eyes and lower blood pressure," often cited in later generations, is not an original Chinese term.The original text only states "brightens the eyes and treats headaches and migraines." The concept of "blood pressure" did not exist in ancient times; "lowering blood pressure" is a modern interpretation added by later generations. It is inaccurate to regard "lowering blood pressure" as an original quote from the Compendium of Materia Medica.

Why is mung bean water green? Common explanations need to be corrected.

Regarding the color of mung bean water (or mung bean soup), there's a common explanation that it's because "mung beans naturally release chlorophyll during soaking." This explanation...Not accurateThe mung bean water is yellowish-green, mainly due to...Polyphenols (including flavonoids and tannins) dissolved from mung bean skinsThese substances will oxidize and polymerize when they encounter oxygen, alkaline water, or metal ions such as iron, causing the soup to gradually turn yellow-red or even reddish-brown. Boiling with weakly acidic water or purified water and covering the pot to reduce contact with air helps to maintain the green color (the same explanation can be found in popular science articles from the College of Food Science and Nutritional Engineering at China Agricultural University and relevant government popular science articles in Guangdong Province).

Interestingly, this science of "color" has recently seen direct animal studies. A study using a mouse heat stress model compared...Normal green mung bean soup and mung bean soup that has turned red due to oxidationThe results showed that mung bean soup helps regulate oxidative stress, inflammatory markers, and gut microbiota; and after the soup turned red,The total polyphenol and flavonoid contents decreased by approximately 181 TP4T and 171 TP4T, respectively.(Ran et al.,Nutrients(2026). This provides a modern interpretation of the traditional practice of "taking mung bean soup to avoid excessive oxidation," but it is still based on animal experiments and cannot be directly equated with human effects.

Nutritional value of mung beans and other studies

According to the USDA FoodData Central, 100 grams of dried mung beans (FDC ID 174256) contain: 347 kcal, 23.9 g protein, 1.15 g fat, 62.6 g carbohydrates, 16.3 g dietary fiber, 1,246 mg potassium, 189 mg magnesium, 132 mg calcium, 6.74 mg iron, and 625 μg folic acid. After cooking, due to water absorption and dilution, 100 grams contain approximately 105 kcal, 266 mg potassium, and 159 μg folic acid (FDC ID 174257). Therefore, mung beans are...High in potassium, high in fiber, and rich in folic acidIngredients.

In addition, laboratory studies have also been conducted on the active components of mung bean peel: C-glycoside flavonoids (isovitexin, vitexin) in mung bean peel have shown in in vitro and animal experiments to inhibit pancreatic lipase and α-glucosidase (Ruan et al.).Plant Foods for Human Nutrition(Sun et al., 2023); The conjugated polyphenols in the dietary fiber of mung bean peel also have α-glucosidase inhibitory and antioxidant activities (Sun et al., 2023).Food Research International(2022). An in vitro digestion study found that...The heating method affects the digestibility of mung bean starch.Heating can convert slow-digesting and resistant starches into fast-digesting starches, and removing proteins or lipids significantly increases starch digestibility and estimated glycemic index (Hou et al.).Plant Foods for Human Nutrition(2020). This aligns with the traditional experience that "mung bean soup should not be cooked for too long," but it should be noted that this study was conducted in vitro.

How to make mung bean water? Instructions and frequently asked questions.

Combining traditional Chinese medicine practices with the above research, you can make mung bean water at home as follows:

1. Wash the mung beans and remove any impurities.
2. Soak in warm water (about 60 to 70°C), or heat briefly over low heat.Polyphenols from mung bean skins dissolveThe soaking liquid/broth is ready when it turns a light green color.
3. Strain the mung bean water, let it cool, and then refrigerate it before drinking. The mung beans can be cooked separately into mung bean porridge or mung bean rice; don't waste them.

Traditional Chinese Medicine RecommendationsPeople with a constitution prone to dampness and heat, and a thick, greasy tongue coating, can drink only mung bean water without cooking the mung beans until they are very soft.To enhance its diuretic and detoxifying effects, the beans can be cooked until very soft. These two approaches differ, and it's not true that "cooking makes it harmful." The claim that "cooking releases starch, increasing dampness in the body" falls under the framework of Traditional Chinese Medicine. From a food perspective, while cooking until soft does cause starch to gelatinize and dissolve, and the soup to thicken, resulting in different textures and components, this shouldn't be considered a taboo.

If someone has a weak spleen and stomach and is prone to diarrhea, a common approach in Traditional Chinese Medicine is...Add white rice or a small amount of glutinous rice when cooking mung beans.(For example, a bowl of mung beans can be paired with one-third of a bowl of white rice) to balance the cooling properties of the mung beans with the neutral properties of the grains.

Who should be especially careful when drinking mung bean water?

• Those with weak spleen and stomach, cold hands and feet, and prone to diarrheaIt is advisable to drink in small amounts and avoid drinking it chilled.
• Patients with kidney disease or those who need to restrict potassiumMung beans are high in potassium (1,246 mg per 100 grams of dried beans). Consult a doctor or registered dietitian before drinking large amounts of mung bean water or eating mung beans.
• People currently taking traditional Chinese medicine or long-term medicationIt is advisable to consult a traditional Chinese medicine practitioner or pharmacist first.
• Pregnant women, young children and the elderlyIt is advisable to consume in moderation and at room temperature.

What's the difference between mung bean water and red bean water?

Red bean water (generally referring to adzuki bean water) was once very popular. Traditional Chinese medicine believes that both mung beans and adzuki beans have diuretic effects, but...Mung beans are more effective at clearing heat, while adzuki beans (red beans) are more focused on promoting diuresis and reducing swelling.The Compendium of Materia Medica also records that red beans "can promote diuresis and reduce swelling." For the purpose of relieving summer heat, mung beans are more effective at clearing heat; however, for reducing edema, red beans are more commonly chosen. For the actual effects and applicability of red bean water in reducing edema, please refer to […].Causes and Evidence of Edema〉。

Is it okay to eat refreshing desserts in the summer?

Aiyu jelly, grass jelly, mung bean soup, and mung bean and barley water are all familiar cooling foods that not only relieve summer heat but also improve mood. Traditional Chinese medicine reminds us of the importance of these foods...It has a cooling nature, and some people may experience diarrhea after consuming it.At this time, you might as well try "mung bean water", which also has a heat-clearing effect and is relatively less burdensome on the stomach and intestines.

Besides the issue of "coolness," there are two other points worth noting:Sugar and food safetyThese types of desserts often contain a lot of sugar; a single bowl may contain a significant portion of the daily recommended sugar intake. For a list of the most easily overlooked sources of sugar in our daily lives, please refer to [link to relevant information].Hand Shaken Drinks: Break Your Daily Sugar Intake in Just One Cup> Iced desserts also involve issues such as microorganisms and lactose; see < for details>.Summer Heat Relief and Individuals with Hot or Cold Constitutions: Timing, Quantity, and Safety Precautions for Eating Ice〉。

A practical compromise is:Use room temperature or slightly chilled instead of chilled, reduce or omit sugar, and control the portion size by serving half a bowl.This way, you can cool off in the summer without consuming too much sugar and coldness at once.

Summer routine: late to bed, early to rise, and short afternoon naps

Traditional Chinese medicine believes that summer living habits should follow the natural law of "long days and short nights". The Yellow Emperor's Inner Classic says "go to bed late and get up early, without being averse to the sun". Researchers at the Chinese University of Hong Kong also mentioned in their discussion on seasonal health preservation that in summer it is advisable to go to bed late and get up early, and eat more foods that clear heat and promote urination (watermelon, bitter melon, tomato, mung beans, cucumber, etc.).

It needs to be emphasized that "staying up late"It is not advisable to go past midnight.Furthermore, "going to bed late and waking up early" does not mean shortening sleep time—the overall sleep duration should still be sufficient. Long-term sleep deprivation or sleeping too little can actually affect immunity, mood, and metabolism.

As for a midday nap, traditional Chinese medicine has the concept of "midday nap," suggesting taking a short nap during the midday period.The time should be between 20 and 30 minutes.Taking a nap that is too long or too late can make you feel more tired after waking up and disrupt your nighttime sleep rhythm. This is also supported by epidemiological studies: a study involving 9,247 middle-aged and elderly people found that...Total sleep time of less than 6 hours and a high proportion of daily sleep time spent napping (≥0.4%) are both associated with an increased risk of hypertension.(Lin et al.,Clinical Cardiology(2023). For a more comprehensive understanding of the relationship between sleep duration and health, please refer to <Does excessive sleep pose health risks? Doctors explain the relationship between sleep duration and health.〉。

Daily care for skin and digestive system

Summer brings more skin and gastrointestinal problems, so in addition to diet, daily habits are equally important.

Skin: Sweating is a key factor

Sweating is a normal mechanism for heat dissipation, but in humid and hot weather, sweat remains on the skin's surface for extended periods, leading to problems. Studies indicate that in patients with atopic dermatitis...Sweat retention, blockage of sweat gland ducts, and sweat seepage into skin tissue are associated with itching and worsening of symptoms.One mechanism is the weakening of the tight junctions of sweat glands, allowing sweat to seep into the dermis, creating a so-called "endocrine response of sweat," which triggers stinging and itching sensations (Murota et al.).Allergology International, 2018; same team,Experimental Dermatology(2019). This also explains why people with atopic dermatitis are particularly prone to itching when it's hot, sweaty, or emotionally stressed.

The countermeasure isWipe away sweat or rinse off as soon as possible, keep clothes dry and breathable, and change clothes frequently.To avoid sweat remaining on the skin for extended periods, it's advisable to reduce the intake of high-sugar and high-glycemic foods, avoid fried foods, and refer to […].Can eczema and acne be improved with supplements? The roles and boundaries of zinc, probiotics, and vitamin D.To learn about common skin care concepts, refer to the UK National Health Service (NHS) guidelines.Atopic eczema>and<AcneThe page also contains useful instructions.

Digestive system: Eat light meals, eat regularly, and pay attention to food safety.

Hot weather makes food spoil easily, increasing the risk of gastrointestinal infections. Besides eating more light and easily digestible foods, it's also important to ensure ingredients are fresh, thoroughly cooked, and kept at room temperature for extended periods. For a deeper understanding of Traditional Chinese Medicine's concepts of the spleen and stomach, and the properties of hot and cold foods, please refer to […].How does Traditional Chinese Medicine (TCM) regulate the digestive system? Daily health maintenance methods including diet, acupressure, and food therapy.>; the basic principles of a balanced diet can be found in <Balanced Diet: Understanding the Six Food Groups〉。

When should you seek medical attention?

Summer health maintenance is a form of routine care and cannot replace medical treatment. If the following symptoms occur, you should seek medical attention as soon as possible:

• Suspected heatstrokeSymptoms may include dizziness, headache, nausea, shortness of breath, and confusion. If body temperature rises to extreme levels (generally above 40°C), generalized convulsions or loss of consciousness may occur. Immediate cooling and calling the police are necessary. 999 Seeking assistance from the Centre for Health Protection, Department of Health, Hong Kong.
• skin problemsSymptoms include redness, swelling, itching, persistent worsening of pimples, oozing, pus formation, expansion of the affected area, or fever.
• Gastrointestinal problemsSymptoms include: persistent diarrhea or vomiting, signs of dehydration (dry mouth, decreased urination, dizziness, fatigue), bloody or black stools, and severe abdominal pain.
• other: Any symptoms that persist for several days without improvement or affect daily life.

also,Patients with chronic diseases (heart disease, high blood pressure, kidney disease, diabetes), pregnant women, the elderly, infants and young children, and overweight individualsThose at high risk of heatstroke should take extra care during hot weather. If you plan to make significant changes to your diet (such as drinking large amounts of mung bean water, consuming aloe vera, or any traditional Chinese medicine dietary therapy), it is recommended that you consult a doctor, registered dietitian, or traditional Chinese medicine practitioner first.

Frequently Asked Questions

When is Grain in Ear (芒种)? Is the date the same every year?

Grain in Ear (芒种) is the ninth of the twenty-four solar terms and the third solar term of summer. It doesn't fall on a fixed day, but rather according to the sun's ecliptic longitude reaching 75°, therefore it occurs annually around [date missing] in the Gregorian calendar. Between June 5th and 7thThe event lasts for about 15 days, until before the summer solstice.

What exactly does "strengthening the spleen and removing dampness" mean?

"Strengthening the spleen and eliminating dampness" is a concept in Traditional Chinese Medicine (TCM). TCM believes that the spleen governs the transformation and transportation of fluids. In summer, damp heat easily "strangles the spleen," leading to fatigue, abdominal distension, poor appetite, and loose stools. "Eliminating dampness" involves adjusting diet and lifestyle to help the body restore normal fluid metabolism. It's important to note that "dampness" in TCM is not a measurable indicator in modern medicine and should not be confused with concepts like edema or dehydration. Practical application involves eating light, easily digestible foods, consuming plenty of high-water-content fruits and vegetables, and reducing oily and fried foods.

Does mung bean water really have a cooling effect, or is it just a placebo effect?

Traditional Chinese medicine (TCM) considers mung beans to be cooling in nature, capable of clearing heat and detoxifying, relieving summer heat, and promoting urination—this is the TCM description of their effects. From a modern perspective, current animal studies have observed that mung bean soup helps regulate oxidative stress, inflammatory markers, and gut microbiota under heat stress (Ran et al., 2026), providing a research direction for traditional experience. However, these are still animal experiments and cannot be directly equated to human effects. It can be understood that mung bean water is a low-calorie, sugar-free, and refreshing drink that helps replenish fluids. Combined with some laboratory evidence supporting its active ingredients, it is reasonable to consider it a daily summer beverage.

Why do some people say that mung bean water "releases chlorophyll"?

This statement is inaccurate. The yellowish-green color of mung bean water mainly comes from the dissolving of the mung bean skins.Polyphenols (flavonoids and tannins)It's not chlorophyll, but rather the phenols themselves. These polyphenols oxidize and polymerize when they encounter oxygen, alkaline water, or metal ions, causing the soup to turn from green to reddish-brown. Therefore, to maintain the green color, use purified water, add a few drops of lemon juice, or cover the soup to reduce air contact.

Is it bad if mung beans are overcooked?

No. Whether to cook it until soft or not is a matter of preference: drinking only the broth is for its cooling properties; cooking the beans until soft allows them to be used for their diuretic and detoxifying effects, and mung beans themselves also have nutrients (protein, potassium, folic acid, dietary fiber). The starch dissolving and thickening of the broth after cooking until soft is a normal change and should not be considered a contraindication. The idea that "cooking until soft increases dampness" is a traditional Chinese medicine explanation, not a conclusion from modern nutrition. People with weak spleen and stomach can add white rice or a small amount of glutinous rice to the broth to alleviate the coldness.

What's the difference between mung bean water and red bean water?

Traditional Chinese medicine believes that both mung beans and red beans have diuretic effects, but mung beans are more focused on clearing heat, while red beans are more focused on promoting diuresis and reducing swelling. For relieving summer heat, mung beans are more suitable; for reducing edema, red beans are more commonly chosen. For the actual effects and applicable situations of red bean water, please refer to the dedicated article on edema on this website.

Do mangoes and lychees make your skin worse?

It's incorrect to say that "eating this will definitely cause acne." Currently, the most widely accepted evidence is...Overall Dietary PatternHigh glycemic load and dairy products may be associated with acne, while low glycemic index diets have been shown to improve acne in studies. Mangoes and lychees are high in sugar, so people with inflamed skin or recurring acne should limit their intake; moderate consumption is generally fine for most people, as the fruits themselves provide vitamin C, potassium, and dietary fiber.

Can I grow my own aloe vera to eat?

It is not recommended to consume aloe vera indiscriminately. There are many varieties of aloe vera, but only a few are edible (such as Aloe barbadensis). The yellow sap from its peel and subcutaneous layer contains aloin (anthraquinones), which can irritate the intestines, causing abdominal pain and diarrhea, and may also stimulate uterine contractions. Authorities in Taiwan stipulate that aloe vera must be completely peeled before consumption, and the daily intake of aloin should not exceed 10 mg. Pregnant women, breastfeeding women, menstruating women, children under 12 years old, and those with gastrointestinal discomfort or kidney disease should avoid consumption. If you wish to consume aloe vera, choose a clearly edible variety and process it thoroughly. Certain groups should avoid it altogether.

Will staying up late and waking up early in the summer lead to insufficient sleep?

"Going to bed late and waking up early" is a traditional Chinese medicine recommendation to align with the longer days and shorter nights of summer. However, "going to bed late" should not exceed midnight, nor does it mean you can shorten your sleep. Overall sleep duration should still be sufficient; otherwise, it will affect immunity, mood, and metabolism. If you feel tired during the day, you can make up for it with a short nap.

How long should a nap be?

General recommendations 20 to 30 minutesA nap that is too long can make you feel more tired after waking up and may interfere with nighttime sleep; some studies have also found that a high proportion of daily sleep time spent napping is associated with an increased risk of hypertension (Lin et al., 2023). Napping time should also not be too late, avoiding napping close to evening.

Who should be especially careful when drinking mung bean water?

People with weak spleen and stomach, prone to diarrhea, and cold hands and feet should drink it in small amounts and avoid drinking it iced; patients with kidney disease or those who need to restrict potassium should consult a doctor or nutritionist before drinking large amounts of mung beans, as they are high in potassium; those who are taking Chinese medicine or long-term medications should consult first; pregnant women, young children and the elderly should drink it in moderation and at room temperature.

Data Sources and Health Disclaimer

Source:

• China Meteorological Administration.Grain in Ear (芒种) - one of the 24 traditional Chinese solar terms> (Date of Grain in Ear solar term, 75° longitude of the sun, and climate characteristics).
• Department of Health, Hong Kong, Chinese Medicine Affairs Division.Traditional Chinese Medicine Health Preservation in Four Seasons—Summer Heatstroke Prevention> (Summer heat damages body fluids, summer dampness impairs the spleen; summer diet should be light, drink plenty of water, and consume appropriate amounts of chilled drinks).
• Hong Kong Chinese Medicine Council.Official website(Hong Kong's Chinese Medicine and Registered Chinese Medicine Practitioner System).
• Centre for Health Protection, Department of Health, Hong Kong.Beware of heatstroke in the hot summer> (Heat exhaustion and symptoms of heatstroke, body temperature threshold of 40℃, key populations, and six preventive measures).
• Student Health Service, Department of Health, Hong Kong.Dental care(General recommendations for oral and dietary hygiene, see further reading).
• The National Center for Complementary and Integrative Health (NCCIH) of the United States.Aloe Vera> (There is limited evidence regarding the stimulant laxative effect of oral aloe vera gel).
• Taiwan Food and Drug Administration, Ministry of Health and Welfare (reprinted from local health bureau).Understanding Aloe Vera> (Aloe vera must be completely peeled before consumption; the daily intake of aloin should not exceed 10 mg; warnings must be clearly stated; consumption is not recommended for certain groups).
• Wikisource.Compendium of Materia Medica, Grains III (Mung Beans)(The original text on mung beans states: "It replenishes vital energy, harmonizes the five internal organs... When used as a pillow, it can improve eyesight and treat headaches and dizziness.")
• USDA FoodData Central.Mung beans, mature seeds, raw (FDC ID 174256)、Mangos, raw (FDC ID 169910)、Litchis, raw (FDC ID 169086)(Nutrients in mung beans, mangoes, and lychees).
• Ran H et al. A Comparison Between Normal and Reddened Mung Bean Soup: Beneficial Effects on the Regulation of Oxidative Stress, Inflammation, and Gut Microbiota in Mice with Heat Stress-Induced Damages. Nutrients. 2026. PMID 42514422。
• Ruan JC et al. In vitro and in vivo Inhibitory Activity of C-glycoside Flavonoid Extracts from Mung Bean Coat on Pancreatic Lipase and α-glucosidase. Plant Foods Hum Nutr. 2023. PMID 37351712。
• Sun N et al. Purification, composition and activity of bound polyphenols from mung bean coat dietary fiber. Food Res Int. 2022. PMID 36461233。
• Hou D et al. In Vitro Starch Digestibility and Estimated Glycemic Index of Mung Bean (Vigna radiata L.) as Affected by Endogenous Proteins and Lipids, and Exogenous Heat-Processing Methods. Plant Foods Hum Nutr. 2020. PMID 32815037。
• Zhang X et al. Effects of Momordica charantia L. supplementation on glycemic control and lipid profile in type 2 diabetes mellitus patients: A systematic review and meta-analysis of randomized controlled trials. Heliyon. 2024. PMID 38784554。
• Moradi A et al. The effect of okra (Abelmoschus esculentus) on lipid profiles and glycemic indices in Type 2 diabetic adults: Randomized double blinded trials. Phytother Res. 2020. PMID 32706159。
• Reynolds RC et al. Effect of the glycemic index of carbohydrates on Acne vulgaris. Nutrients. 2010. PMID 22253996。
• Meixiong J et al. Diet and acne: A systematic review. JAAD Int. 2022. PMID 35373155。
• Murota H et al. Sweat in the pathogenesis of atopic dermatitis. Allergol Int. 2018. PMID 30082151。
• Murota H et al. Why does sweat lead to the development of itch in atopic dermatitis? Exp Dermatol. 2019. PMID 31152459。
• Lin L et al. Associations of siesta and total sleep duration with hypertension or cardiovascular diseases in middle-aged and older adults. Clin Cardiol. 2023. PMID 36510696。
• The UK's National Health Service (NHS)Atopic eczema、Acne(Skin care advice).

Health Disclaimer:This article is for general health and nutrition information only. The Traditional Chinese Medicine (TCM) content presented is a compilation of TCM theoretical frameworks and should not replace professional medical diagnosis, treatment, or individual nutritional advice. Everyone's constitution, health condition, and disease risk are different; dietary and lifestyle adjustments should be tailored to individual circumstances. If you have a chronic illness (heart disease, high blood pressure, kidney disease, diabetes, etc.), are pregnant, breastfeeding, elderly, infant, overweight, or are currently taking prescription medications or TCM, consult a doctor, registered dietitian, or TCM practitioner before adjusting your diet or consuming any dietary therapy. If you experience suspected heatstroke symptoms (dizziness, headache, nausea, shortness of breath, confusion, or body temperature exceeding 40°C), immediately cool down and call 999 for help. If symptoms persist or worsen, seek medical attention as soon as possible.