Water Shield Soup (Chuncai Geng): A Dietary Therapy for Emaciation
"Water Shield Soup (Chuncai Geng)" is an ancient dietary-therapy formula indicated for weakness of the spleen and stomach qi, inability to take food and drink, weakness of the limbs, and progressive emaciation. This formula originates from the Song-dynasty text Shengji Zonglu (General Records of Divine Assistance); in Puji Fang it carries the alternative name "Crucian Carp Soup" (Jiyu Geng).
The formula consists of: water shield (Brasenia schreberi) and crucian carp (wrapped in paper, roasted until cooked, then ground), each 4 liang (120 g), together with tangerine peel, fresh ginger, and scallion white, boiled into a soup (geng, essentially a porridge). It is taken on an empty stomach, once or twice daily.
Water shield is an edible aquatic herb. Its rhizome is small, its stems slender and highly branched; because its tender shoots look like fine threads, it is called water shield. It is native to southeastern China, especially the marshlands of the Yangtze River basin; the water shield from Hangzhou's West Lake and Jiangsu's Lake Tai is the most famous, and it is still sold in many online shops. The stems and leaves are rich in mucilage, giving a tender, smooth texture. Together with water bamboo (Zizania latifolia) and Japanese sea bass, it is known as one of the "three famous delicacies of the Jiangnan region." The ancients expressed longing for home as "the longing for water shield and perch," showing how popular this vegetable was in antiquity.
Water shield is both food and medicine, with no reported adverse effects or toxic side effects; it can be eaten safely. Traditional Chinese medicine holds that water shield is cold in nature, sweet in taste, and enters the spleen and stomach meridians. It nourishes blood, moistens the lungs, strengthens the stomach, clears heat, and stops diarrhea; it is used for ulcers and boils (yongju), furuncles, hot furuncles, and toxic swellings. Modern pharmacology has shown that water shield has antitumor effects, with some inhibitory activity against gastric and prostate cancers.
Crucian carp is rich in high-quality protein. Simmering water shield together with crucian carp into a soup, then adding tangerine peel, ginger, and scallion white—all of which strengthen the spleen and warm the stomach—provides not only high-quality protein but also improves appetite. It is no wonder that this "Water Shield Soup" can help a person gain weight.
Emaciation is usually a sign of chronic malnutrition. Food-based nourishment is preferable to drug supplementation, and this dietary formula, derived from the practical life experience of the ancients, is worth learning from today.