How does Traditional Chinese Medicine explain the effects of food on health?

Four Qi: Cold, Cool, Warm, and Hot

"The Yellow Emperor's Neijing Su Wen: The Great Treatise on the Correspondence of Yin and Yang ": "Water is yin, fire is yang...... Yang is the Qi and the yin is the taste." It is pointed out that the yin and yang attributes of food develop the classification of cold, cool, warm and hot. "The Yellow Emperor's Neijing Su Wen: The Essence of the Great Treatise": "Treat the cold with hot, and treat the hot with cold" which emphasizes that treatment (including dietary adjustment) needs to reversely adjust the body's temperature according to the cold or hot nature of the food, indirectly indicating that food has cold or hot properties.

Five flavors: sour, bitter, sweet, pungent and salty

"The Yellow Emperor's Neijing Su Wen: The Essence of the Great Treatise": "The five flavors enter the stomach, and each one returns to his favorite attack...... sour enters the liver first, bitterness enters the heart first, sweetness enters the spleen first, pungent enters the lungs first, and saltiness enters the kidneys first." It point out the correspondence relationship between the five flavors, the five internal organs, and the five elements. Sour affects the liver, bitterness affects the heart, sweet affects the spleen, pungent affects the lungs, and saltiness affects the kidneys. "The Yellow Emperor's Neijing: Lingshu Five Flavors" talks about the laxative effect of the five flavors on the five organs, such as "the liver is green, and it is suitable to eat sweet...... The heart is red, and it is suitable to eat sour food", etc. Different flavors correspond to different viscera and produce specific effects. "The Yellow Emperor's Neijing Su Wen: The Generation of the Five Organs": "The heart desires bitterness, the lungs desire bitterness, the liver desires sourness, the spleen desires sweetness, and the kidneys desire saltiness, and these five flavors are combined." The five flavors correspond to the five internal organs, and point out the nourishment or influence of the five flavors on the internal organs.

Movement: rising, descending, floating, sinking

"The Yellow Emperor's 's Neijing Su Wen: The Great Treatise on the Correspondence of Yin and Yang": "The pure yang is the sky, and the turbid yin is the earth...... Clear yang comes out of the upper body, the turbid yin comes out of the lower body", implying the characteristics of rising (upward and outward) and sinking (downward and inward).  "The Yellow Emperor's Neijing" did not directly mention the "rise and fall" of food, and indirectly reflects the example of "rise and fall" focuses on the "body's qi".

"The Yellow Emperor's Neijing Su Wen: The Essence of the Great Treatise": "The high ones should be suppressed, the low ones should be raised... the knotted ones should be dispersed, and the lingering ones should be attacked." It proposes that the Qi should be regulated in reverse according to the severity of the disease (such as "lifting those who are sinking" and "lowering those who are rising"), and the "rising, descending, floating and and sinking" of food is derived from this. For example, rising foods can treat sinking symptoms due to qi deficiency of internal organs (such as rectal prolapse), while sinking foods can treat qi reflux and upward rushing symptoms of the body (such as vomiting).

Meridians/5 organs: lungs, spleen, liver, heart, kidneys

"The Yellow Emperor's Neijing Su Wen Xuanming Five Qi": "The five flavors: sour enters the liver, pungent enters the lungs, bitterness enters the heart, saltiness enters the kidneys, and sweetness enters the spleen, which is called the five flavors entrances." The five flavors correspond to the five internal organs, such as the sour food acts on the liver meridian, and the pungent food acts on the lung meridian. This is the theory of "returning to the meridians". "The Yellow Emperor's Neijing: Lingshu Five Flavors": "The liver is green, and it is suitable for sweetness...... The heart is red, and it is advisable to eat sour ......", which further combines the relationship between the five colors foods and the five viscera (such as sweetness soothing the liver urgency), implying the connection of "food-viscera-meridians". "The Yellow Emperor's Su Wen: The Generation of the Five Organs": "Color and taste are correspond to the five organs: white and acrid correspond to the lungs, red and bitter to the heart, black and salty to kidney, etc." For example, black food (such as black beans) enters the kidney meridian, and white food (such as lily) enters the lung meridian, providing a basis for the "color and taste relating to the meridian/organs", and pointing out that foods of different colors nourish and treat different internal organs.

Efficacy: Treats symptoms of exterior and interior, cold and heat, deficiency and excess, yin and yang.

The effects of foods can harmonize the body's yin and yang, replenish deficiency and eliminate excess, reduce fever and drive away cold, relieve exterior symptoms and treat interior symptoms.

3.1 Four Qi (Cold, Heat, Warm, Cool)

• Cold food (watermelon, mung bean, winter melon, loofah): It is used for heat clearing, fire relief, detoxification, suitable for heat constitution (dry mouth, constipation, diuretic). 
• Warm food (ginger, onion, green onion, chili): It is suitable for dissipating cold, warming yang, and invigorating blood, and is used for cold constitution (cold intolerance, diarrhea, and relieving the surface). 
• Neutral food (honey, rice, pork, yam): mild in nature, can strengthen the spleen and stomach.  

3.2  Five flavors (sour, bitter, sweet, pungent and salty).

• Sour (hawthorn, black plum): helps digestion and eliminates stagnation in body, astringent and and solidifies (antiperspirant, antidiarrheal).   
• Bitter (bitter gourd): clear heat and dampness (reduce fire, laxative).
• Sweet (maltose, red dates): nourishes and harmonizes the stomach, relieves pain (strengthens the spleen, moisturizes dryness).
• Acrid (green onion, ginger): Spicy (onion, ginger): Disperses qi and promotes circulation, induces sweat and relieves exterior symptoms (relieves exterior symptoms, promotes blood circulation).
• Salty (jellyfish, kelp): softening and dispersing lumps (reducing swelling and resolving phlegm).

3.3  Meridians/ Organs (lungs, spleen, liver, heart, kidneys).

Foods are classified according to their nourishing and therapeutic effects on specific organs or meridians:

• Lily and snow pear belong to the lung meridian: moisturize the lungs and relieve cough.
• Yam and chicken belong to the spleen meridian: strengthen the spleen and replenish qi.
• Rose and jasmine belong to the liver meridian: soothe the liver and regulate qi.
• Cypress seeds and pig heart belong to the heart meridian: nourish the heart and calm the mind.
• Walnuts and millet belong to the kidney meridian: nourish the kidney and strengthen the waist.

3.4  Movement: rise, fall, float and sink (rise means rising, fall means falling, float means divergence and sink means convergence. The movement of food is used to regulate the Qi in the human body). 

3.4.1  Floating food (movement: upward, outward) 

• Effect of food: affecting the upper part or surface of the human body.
• Food functions: dispersing and relieving exterior symptoms, raising yang and lifting the sunken, promoting the flow of qi and blood.
• Food examples (green onion, ginger, mint): dispel wind and cold, and raise Yang energy; (lotus leaf and cimicifuga heracleifolia): light and clear upward movement in nature, can cure dizziness and prolapse of internal organs.

3.4.2  Sinking food (direction: downward, inward)

• Effect of food: affecting the lower parts or internal organs of the human body.
• Food functions: relieve nausea and vomiting, promote bowel movements and urination, calm the nerves and soothe the mind.
• Food examples ( winter melon, coix seed) : diuretic and dehumidifying; (almonds, pears, and lilies): reduce qi and relieve cough, moisten the lungs and reduce internal heat.

Lifting foods can lift and are mainly used for sinking symptoms. For example, Astragalus and Cimicifuga heracleifolia can both elevate the Qi of the middle burner, so they are suitable for gastroptosis, uterine prolapse, and rectal prolapse caused by chronic diarrhea.

Descending foods can descend and inhibit, and are mainly used to treat symptoms caused by upward movement of qi and ascending fire and heat. For example, dried tangerine peel can reduce gastric qi and is therefore considered suitable for vomiting, while gentian is effective in reducing diseases caused by liver and gallbladder fire and heat inflammation.

Floating food can rise and disperse, and is mainly used for diseases on the body surface. Mint and burdock seed are both dispersing in nature, so they are suitable for dispersing wind-heat, clearing the head and eyes, and relieving rashes and sore throat.

Sinking foods can lower qi, promote diuresis and relieve constipation, and are mainly used for diseases of the internal organs or lower part of the body. For example, rhubarb, which promotes defecation, and akebia, which induces urination, are both sinking food.

4.1 Reconcile yin and yang

Heat syndrome (such as internal heat) is balanced with cold foods (pears, green tea).

For cold syndrome (such as uterine cold), use warm foods (brown sugar, longan) to warm and nourish.

4.2 Tonifying the Deficiency and Eliminating the Excess

Replenish the deficiency: For qi deficiency, use astragalus and millet to replenish qi; for blood deficiency, use spinach leaves and pig liver to replenish blood; for yin deficiency, use black sesame and lily to replenish yin; for yang deficiency, use cordyceps and mutton to replenish yang.

Purge the excess: If there is excessive dampness, use coix seed and red bean to remove dampness. If you have a cough with phlegm, you can use seaweed and kelp to reduce phlegm and relieve cough. If there is blood stasis and pain, use peach kernel and rice vinegar to promote blood circulation, remove blood stasis and relieve pain.

Tonifying Qi, tonifying blood, replenish yang, replenish yin, regulating Qi, activating blood circulation, warming the interior, digesting food, removing dampness, clearing away heat, resolving phlegm, relieving exterior symptoms and astringing, etc.  

Based on the food classification methods: four properties and five flavors, rising and falling, meridians and effects, we can derive applications for physical health. 

Chinese yam: sweet, neutral, spleen, lung, kidney meridians

Efficacy: Replenishes Qi, nourishes the spleen and lungs, produces fluid and moistens the lungs, strengthens the kidneys and stops spermatorrhea.

Application:  a. Spleen Qi deficiency. Used for loss of appetite, fatigue, and loose stools.

b. Lung Qi deficiency. Used for chronic cough and asthma

c. Kidney Qi deficiency. Used for nocturnal emission, increased leucorrhea, frequent urination, etc.

Lily: sweet, cold, lung and heart meridians.

Efficacy: Nourishes lung yin and relieves cough, clears the heart and soothes the mind.

Application:  a. Lung yin deficiency. Used for dry cough and hemoptysis.

b. Heart yin deficiency. Used for persistent low fever, irritability, insomnia and dreaminess caused by heart fire.

Cinnamon: pungent, sweet, hot, kidney, spleen, heart and liver meridians.

Effect: replenishing fire and yang, dispelling cold and relieving pain, warming and unblocking meridians

Application:  a. Kidney Yang deficiency. Used for aversion to cold, soreness of waist and knees, impotence, and frequent urination.         

b. Spleen and kidney yang deficiency syndrome. Used for stomachache, abdominal pain, poor appetite and loose stools.

c. Qi stagnation syndrome caused by blood stasis and cold stagnation. For various pains, such as arthritis and back pain

Lotus seeds: sweet, astringent, neutral, spleen, kidney and heart meridians.

Efficacy: Nourishes the spleen and stops diarrhea, nourishes the kidney and consolidates essence, nourishes the heart and calms the mind.

Application:  a. Spleen Qi deficiency syndrome. Used for loss of appetite and chronic diarrhea caused by spleen deficiency.

b. Kidney Qi deficiency syndrome. Used for spermatorrhea and spermatorrhea caused by kidney deficiency.

c. Heart qi deficiency . Used for symptoms such as irritability, palpitations, insomnia caused by weak heart.

Pumpkin seeds: sweet, neutral, stomach and large intestine meridians.

Effect: Deworming

Application: Parasitic diseases: used for tapeworm infestation, ascariasis and schistosomiasis.

Hawthorn: sour, sweet, slightly warm, spleen, stomach, and liver meridians.

Efficacy: Digests food, eliminates stagnation, promotes qi and removes blood stasis.

Application:   a.  Food stagnation and qi stagnation syndrome. Used for abdominal distension, poor appetite, abdominal pain, diarrhea, indigestion and other symptoms.

             b.  Blood stasis syndrome. Used for postpartum abdominal pain and lochia caused by blood stasis

Honeysuckle: sweet, cold, lung, heart and stomach meridians.

Efficacy: Clears away heat, detoxifies, and dispels wind-heat.

Application:  a.  Wind-heat syndrome: used for fever, slight aversion to wind-heat, and sore throat caused by exogenous wind-heat.

b.  Heat evil syndrome: used for high fever, thirst, and drowsiness. Evil heat invades the lung qi system.

c.  Others: used for carbuncle, enteritis and dysentery.

Traditional Chinese medicine selects appropriate food ingredients based on individual constitution and symptoms to achieve the purpose of disease prevention and health enhancement. By understanding the theories of the Four Qi and Five Flavors, the Meridians, and Motion Directions, we can use our daily diet more effectively to maintain our health.