The sultana is a "white" (pale green), oval seedless grape variety also called the sultanina, Thompson Seedless (United States), Lady de Coverly (England), and oval-fruited Kishmish (Iran, Turkey). It is assumed to originate from the Asian part of the Ottoman Empire. In some countries, especially Commonwealth countries, it is also the name given to the raisin made from it or from larger seedless grapes; such sultana raisins are often called simply sultanas or sultanis. These are typically larger than Zante currants (which are actually a kind of dried grape, not currants in the botanical sense), and the Thompson variety is smaller than many seeded raisins. In the USA, the name "raisin" is applied to all dried grapes, so that the breakfast cereal known "Sultana Bran" in Australia and the United Kingdom is called Raisin Bran in the United States. Other types of raisins like Golden, Sundried and etc are coming from different drying process of Sultana raisins.
Another seedless grape variety from the former Ottoman Empire, the round-fruited Kishmish, is also dried to make a larger sultana raisin especially in Iran Empire.
Raisins can contain up to 72% sugars by weight, most of which is fructose and glucose. They also contain about 3% protein and 3.7%–6.8% dietary fiber. Raisins, like prunes and apricots, are also high in certain antioxidants, but have a lower vitamin C content than fresh grapes. Raisins are low in sodium and contain no cholesterol.
Data presented at the American College of Cardiology's 61st Annual Scientific Session in 2012 suggests that, among individuals with mild increases in blood pressure, the routine consumption of raisins (three times a day) may significantly lower blood pressure, especially when compared to eating other common snacks.