According to Traditional Chinese Medicine, the five flavors—salty, sweet, sour, bitter, and spicy—correspond to the five Zang organs of the human body, each with its own function. When consumed in moderation, these five flavors nourish the five organs; however, excessive intake can disrupt the body's balance, damage the organs, and lead to disease. The "Peng Zu's Treatise on Nurturing Life and Health" states: "The five flavors should not be indulged in excessively; too much sour harms the spleen, too much bitter harms the lungs, too much spicy harms the liver, too much sweet harms the kidneys, and too much salty harms the heart." Conversely, this means that people with a weak spleen and stomach should eat less sour food; those with insufficient liver blood should eat less spicy food; people with kidney deficiency should not eat too many sweets; and those with heart issues must strictly control their intake of salty food.
Excessive sour harms the spleen. Sour flavor can nourish the liver, but too much sour food can cause an excess of liver Qi, which then overacts on the spleen and stomach, leading to their dysfunction. The spleen governs the muscles and its radiance is reflected in the lips. Therefore, consuming too much sour food can cause the lips to lose their luster and turn outward. It is recommended that people who often experience indigestion after meals, as well as those with symptoms of spleen deficiency such as loose stools and a weak voice, should eat less sour food.
Excessive sweet harms the kidneys. Sweet flavor can nourish the spleen, but excessive sweet food can cause an excess of spleen Qi, which then overacts on the kidneys. Since the kidneys govern the bones and store essence, and their radiance is reflected in the hair, eating too much sweet food can cause the hair to lose its luster and lead to hair loss. Those who often experience soreness in the lower back and knees, as well as tinnitus and hearing loss, often show signs of kidney essence deficiency and are advised not to eat too much sweet food.
Weak stomach? Eat less sour. Poor eyesight? Eat less spicy!
Excessive bitter harms the lungs. Bitter flavor can nourish the heart, but too much bitter food can overact on the lungs. Therefore, when we consume too many bitter things, it can damage lung function. The lungs govern the skin and body hair; eating too much bitter food can cause the skin to become dry and withered, and lead to hair loss. Those who are prone to coughing and producing phlegm often show signs of lung Qi deficiency and should try to limit their intake of bitter foods.
Excessive spicy harms the liver. Overindulging in spicy food can cause an excess of lung Qi, which then overacts on the liver. Since the liver stores blood and governs the sinews, eating too much spicy food can reduce the elasticity of the sinews. If blood fails to reach the nails, they can become brittle and prone to cracking. Therefore, those who frequently experience dizziness, a dull complexion, and blurred vision due to liver blood deficiency should eat less spicy food.
Excessive salty harms the heart. Salty flavor can nourish the kidneys, but eating too much of it can overact on the heart and damage its function. The heart governs the blood; consuming too much salty food can inhibit the production of blood, causing the vessels to congeal and the complexion to turn dark. Therefore, people who often experience symptoms of heart Qi deficiency such as palpitations, shortness of breath, and chest pain should eat less salty food.