To avoid stomach difficulties, experts recommend drinking water one hour after eating fruits. The fiber in litchis can increase how long it takes for your body to digest food, so you should wait at least an hour after eating a litchi before drinking any liquid. Litchis are high in acid and sugar, and low in calcium, vitamin C, and iron. They are best eaten fresh but can also be stored for several weeks in the refrigerator. Litchis were first cultivated in India more than 5,000 years ago, but they became popular only recently in Europe and America. Believed to have medicinal properties, they are used by some as an eye drop for treating conjunctivitis. Today, litchis are widely grown throughout the world and used primarily for their delicious fruit. There are many varieties of litchi, most of which are native to China. The two main types are the Tainong and the Taihu. The Tainong has smooth skin while the Taihu has rough skin that is often split into three parts: yellow flesh with red tips inside out petals. Litchis contain antioxidant compounds called polyphenols that may help prevent cancer and cardiovascular disease.