Carambola, also known as starfruit, is the fruit of Averrhoa carambola, a species of tree native to the Philippines, Indonesia, Malaysia, India, Bangladesh and Sri Lanka. The Portuguese word carambola, first known use 1598, was taken from Marathi karambal derived from Sanskrit karmaphala. The fruit is popular throughout Southeast Asia, the South Pacific and parts of East Asia. The tree is also cultivated throughout non-indigenous tropical areas, such as in Latin America, the Caribbean, and the southern United States. The fruit has distinctive ridges running down its sides (usually five but can sometimes vary); in cross-section, it resembles a star, hence its name. The entire fruit is edible and is usually eaten out of hand. They may also be used in cooking and can be made into relishes, preserves, and juice drinks. Gastronomy The entire fruit is edible, including the slightly waxy skin. The flesh is crunchy, firm, and extremely juicy. It does not contain fibers and has a texture similar in consistency to that of grapes. Carambolas are best consumed shortly after they ripen, when they are yellow with a light shade of green or just after all traces of green have disappeared. They will also have brown ridges at the edges and feel firm. Fruits picked while still slightly green will turn yellow in storage at room temperature, but will not increase in sugar content. Overripe carambola will be yellow with brown spots and can become blander in taste and soggier in consistency. Ripe sweet type carambolas are sweet without being overwhelming as they rarely have more than 4% sugar content. They have a tart, sour undertone, and an oxalic acid odor. The taste is difficult to compare, but it has been likened to a mix of apple, pear, grape, and citrus family fruits. Unripe starfruits are firmer and sour, and taste like green apples. Ripe carambolas may also be used in cooking. In Southeast Asia, they are usually stewed in cloves and sugar, sometimes with apples. In China, they are cooked with fish. In Australia, they may be cooked as a vegetable, pickled, or made into jams. In Jamaica they are sometimes dried. Unripe and sour type carambolas can be mixed with other chopped spices to make relishes in Australia. In the Philippines, unripe carambolas are eaten dipped in rock salt. In Thailand, they are cooked together with shrimp. The juice from carambolas is also used in iced drinks, particularly the juice of the sour varieties. In Hawaii they are used to make sherbet, while in the Philippines they can be used as seasoning. In India, the juice is bottled for drinking. Benefits Carambola is rich in antioxidants, potassium, and vitamin C; and low in sugar, sodium, and acid. It is also a potent source of both primary and secondary polyphenolic antioxidants. Averrhoa carambola has both antioxidant and antimicrobial activities. Scavenging of nitric oxide (NO) by the fruit extract is dependent on concentration and stage of ripening. Extracts showed antimicrobial activity against E. coli, Klebsiella spp., Staphylococcus aureus, and Pseudomonas aeruginosa. Risks Carambolas contains caramboxin and oxalic acid, both substances are harmful to individuals suffering from kidney failure, kidney stones, or those under kidney dialysis treatment. Consumption by those with kidney failure can produce hiccups, vomiting, nausea, and mental confusion. Fatal outcomes have been documented in some patients. Recent research has identified caramboxin as a neurotoxin which is structurally similar to phenylalanine, and is a glutamatergic agonist. Drug interactions Like the grapefruit, carambola is considered to be a potent inhibitor of seven cytochrome P450 isoforms. These enzymes are significant in the first-pass elimination of many medicines, and, thus, the consumption of carambola or its juice in combination with certain prescription medications can significantly increase their effective dosage within the body. Research into grapefruit juice (its potent enzymes) for instance, identified a significant effect (requires change in dose or other side effects) on common medications when taken concurrently by the patient, including statins, which are commonly used to treat high cholesterol and cardiovascular illness, and benzodiazepines (a sedative tranquilizer drug family that includes diazepam).