The Summer Solstice, also known as the “Summer Festival” or “Summer Solstice Festival.” Ancient people said: “The sun reaches its northernmost point, the longest day, and the shortest shadow, hence it is called the Summer Solstice. ‘To solstice' means to reach an extreme.” The Summer Solstice is the day when the sun travels farthest north, making it the day with the longest daylight hours and the highest angle of the sun in the Northern Hemisphere.
Tang Fang, a mentor in the Sixth Batch of National Experts in Traditional Chinese Medicine (TCM) Academic Experience Inheritance and Professor at Tianjin Medical University, believes that the spleen governs transportation and transformation, while the stomach governs reception and containment; the spleen promotes clearness, and the stomach descends turbidity. When the spleen and stomach coordinate in reception and transformation, promote clearness and descend turbidity, and balance dryness and dampness, they jointly complete the digestion and absorption of food and drink and the distribution of water and grain essence. The Summer Solstice is the time when yang energy is most abundant, and yin energy begins to grow. It is a season where diseases related to spleen deficiency and dampness entrapment are prevalent. It is also a period when weak, chronically ill, and elderly individuals are more likely to experience exacerbations of their conditions, the recurrence of chronic illnesses, and the onset of new diseases. Therefore, she advocates nourishing the spleen and stomach during the transition between yin and yang at the Summer Solstice, in accordance with the seasonal characteristics of yang predominating over yin, as the primary measure for adjusting yin and yang and preventing and treating diseases.
There are narrow and broad definitions of spleen and stomach diseases. Narrowly defined, these refer to diseases of the organs of the spleen and stomach. Broadly defined, they include diseases of multiple organs involved in the processes of reception, transformation, and conduction—i.e., diseases of the spleen-stomach system, affecting multiple levels and functions. Here, we will only discuss the principles of treating spleen and stomach diseases and emphasize the importance of nourishing the spleen and stomach.
Nourishing the Spleen and Stomach: Emphasizing Reinforcement and Regulation
Regardless of whether spleen and stomach diseases are due to deficiency, excess, cold, or heat, the basic pathogenesis involves spleen deficiency and internal stagnation. Treatment should reinforce deficiencies, expel dampness, and regulate qi. A healthy spleen resists evil influences, the expulsion of dampness facilitates spleen qi transport, and the movement of qi eliminates various evils. An abundant and harmonized spleen and stomach qi allows for the generation of blood and qi, and the nourishment of primordial qi.
Reinforcing Deficiencies
The spleen and stomach are the foundation of postnatal development, the source of the generation of blood, qi, and body fluids. All the zang-fu organs, limbs, bones, senses, and meridians depend on the spleen and stomach for nourishment. During the Summer Solstice, the climate becomes noticeably hot, and rainfall increases. Excessive dampness and heat characterize this season. Habits such as consuming raw and cold foods, favoring air-conditioned environments with low temperatures, and taking cold showers are most likely to injure spleen yang. What is spleen yang? Spleen yang refers to the transformation function of the spleen and the heat energy inherent in this process. For the spleen yang to function properly, it requires the warming and assistance of gate-of-life fire (kidney yang). If the spleen yang is damaged, the transport function of spleen qi becomes abnormal, leading to symptoms such as shortness of breath, poor appetite, abdominal distension, and diarrhea, forming a pattern of spleen deficiency. Reinforcing the spleen and promoting qi is the fundamental treatment principle for qi deficiency in spleen and stomach diseases.
According to TCM, “When external heat is at its peak, one should avoid damp heat and not be exposed to cold. Cold causes constriction and prevents the release of qi.” During the Summer Solstice, being in the transition between yin and yang, daily life should also involve protecting yang energy. As the weather gets hotter, sweating increases. Drinking a cup of hot tea can help. Hot tea aids sweat gland perspiration, achieving a cooling effect. Moreover, the bitter taste of tea can clear internal heat and retain body fluids, making it a prime choice for cooling off since ancient times. Besides, beverages like mung bean soup can also be consumed to alleviate heat.
Expelling Dampness
The spleen and stomach play a vital role in regulating the body's fluid metabolism, summarized in TCM as “the spleen governs the transformation of dampness.” When the spleen functions vigorously and the transformation of dampness is normal, ingested fluids can be distributed throughout the body and excreted normally. However, when there is spleen qi deficiency or spleen yang deficiency, the regulation of dampness is disrupted, leading to the retention of dampness. If dampness accumulates in the skin, it can cause edema; if it accumulates in the lungs, it can form phlegm and fluid retention. Thus, TCM posits that “all dampness, swelling, and fullness originate from the spleen.” The spleen prefers dryness and dislikes dampness; spleen deficiency can generate dampness, which in turn produces pathological products like phlegm and fluid retention, further hindering the spleen. This is the main reason for the dysfunction of spleen and stomach transformation.
Research on the relationship between gastrointestinal inflammatory diseases and spleen dampness shows that the treatment of gastrointestinal disorders involving abnormal fluid metabolism often targets the spleen and stomach, primarily employing methods to transform dampness, including aromatic dampness transformation, bitter-warm dampness drying, and mild diuresis. As rainfall increases and humidity rises during the Summer Solstice, exposure to rain or prolonged residence in damp environments can allow dampness to enter through the pores. Dampness is a pervasive pathogenic factor that easily restrains the spleen. Since the spleen governs muscles, symptoms such as muscle pain, heaviness, and fatigue may arise.
Dampness restraining the spleen can also lead to diarrhea. Individuals who might already have a qi deficiency constitution, usually feeling cold and weak, can experience an interaction between internal and external dampness, leading to dysfunction of the spleen and stomach, resulting in diarrhea.
Additionally, some young women, who are inherently cold in constitution, are slender, cold-sensitive, and suffer from dysmenorrhea. If they indulge in cold drinks, the spleen and stomach cannot transform the cold, and with the presence of external dampness, cold and dampness can remain within the body, causing imbalances between cold and heat, increased vaginal discharge, fatigue, and lethargy.
During this season, foods like mung beans and Job's tears porridge, which eliminate dampness, can be consumed. Foods high in fat should be avoided, and people in southern regions can consume slightly spicy foods.
Regulating Qi
The spleen and stomach reside in the middle energizer and serve as the hub for the entire body's qi circulation. Spleen qi should rise to maintain health, while stomach qi should descend to ensure harmony. An orderly rise and fall of qi ensures smooth circulation, completing the cycle of ascending clearness and descending turbidity in the human body.
Functional gastrointestinal diseases and gastrointestinal motility disorders commonly occur during the Summer Solstice, characterized clinically by symptoms such as abdominal distension, abdominal pain, nausea, and vomiting. These fall under the TCM categories of “stagnant fullness,” “stomachache,” and “abdominal pain.” Treatment typically involves herbal formulas that use aromatic herbs to awaken the spleen and harmonize the stomach, focusing on regulating qi circulation and restoring the ascending and descending functions of the spleen and stomach.
During the Summer Solstice, overeating is discouraged as it burdens the spleen and stomach. Fresh fruits and vegetables should be consumed more frequently, and leftover meals should be avoided. According to TCM, “when the spleen is strong, diet and movement are promoted; when the spleen declines, movement slows down.” Many people feel drowsy and sluggish after eating, a condition that becomes more frequent during the Summer Solstice. Daily intake of herbs that lift and strengthen spleen qi can improve mental state.
Nourishing the Middle Energizer: Not Neglecting Liver Regulation
The liver is the hub of qi and governs free flow. The smooth rise and fall of spleen and stomach qi depends on the free flow of liver qi. The spleen and liver are interdependent and mutually constrain each other physiologically, but can influence each other pathologically.
Liver-spleen disharmony syndrome results from impaired free flow of liver qi and weakened transformation of spleen qi, leading to disharmony between the two organs and functional disorder. It is often caused by emotional distress, long-term depression, improper diet, or overwork. Clinically, it manifests as chest and rib-side fullness or stabbing pain, sighing, depression