The water chestnut is rich in protein and carbohydrates, but not high in calories. Traditional Chinese medicine considers the water chestnut a cold-natured food that can clear heat and reduce fire, while also providing nutrition. It is very effective for reducing fever in the early stages of illness; about 10 at a time is sufficient. It also has properties such as cooling the blood and detoxifying, promoting urination and bowel movements, transforming dampness and dispelling phlegm, and aiding digestion to relieve bloating.
In China's Qing Dynasty, the famous expert on warm diseases, Wu Jutong, created a renowned remedy for heat damage to body fluids and thirst called "Five-Juice Drink." This drink is made from the juice of water chestnuts, pears, lotus root, reed rhizome, and ophiopogon. These five juices are all sweet, cold, and cooling, nourishing the yin, making them suitable for patients in the early stages of fever or after a high fever has subsided. However, they are not suitable for consumption during a high fever. In seasons with many respiratory infectious diseases, eating fresh water chestnuts also helps prevent and treat diseases such as cerebrospinal meningitis, measles, pertussis, and acute pharyngitis.
Children often experience fevers in the winter, and water chestnuts are also very suitable for them. They not only help reduce fever but also promote the development of children's teeth and bones.
This is because the phosphorus content in water chestnuts is relatively high among root and stem vegetables. It promotes human growth and development and meets the needs of maintaining physiological functions. At the same time, it can also promote the metabolism of the three major substances in the body—sugar, fat, and protein—and regulate acid-base balance. British research on water chestnuts has also discovered a heat-labile antibacterial component called puchiin, which has a certain inhibitory effect on *Staphylococcus aureus* and *Escherichia coli*, and can also lower blood pressure. This substance also has a preventive and therapeutic effect on lung, esophageal, and breast tumors.
However, water chestnuts should not be eaten raw. As they grow in mud, their outer skin and interior may carry many bacteria and parasites. They must be washed thoroughly and cooked completely before consumption. Furthermore, cooked water chestnuts are sweeter.