Water chestnut (Eleocharis dulcis and Trapa natans) has a history of use in traditional medicine systems, particularly in Chinese and Ayurvedic medicine. In these traditions, water chestnut is sometimes used as a cooling food to help manage digestive complaints, including nausea and vomiting. Historical texts and some herbal compendia refer to its use in recipes or decoctions aimed at soothing the stomach and alleviating mild digestive disturbances. However, the documentation is largely anecdotal, and water chestnut is not a primary remedy for nausea or vomiting in most traditional pharmacopeias. Instead, it may be included as a supportive ingredient in broader digestive formulas.

There is very limited scientific research directly evaluating the effects of water chestnut on nausea or vomiting. No clinical trials or robust preclinical studies have been published that specifically assess its efficacy for these symptoms. Most contemporary references to its use for nausea rely on traditional beliefs rather than empirical evidence. As such, while water chestnut has a minor traditional association with easing digestive upset, the strength of evidence supporting its use for nausea and vomiting is weak, and it should not be considered a primary or evidence-based therapy for these conditions.