Acerola is a small tree that grows in dry areas of the Caribbean and Central and South America. Traditionally, its fruit has been used to treat diarrhea, arthritis, fevers, and kidney, heart, and liver problems. Acerola contains 10–50 times more vitamin C by weight than oranges. Other important substances found in acerola include bioflavonoids, magnesium, pantothenic acid, and vitamin A.

Acerola is primarily marketed as a source of vitamin C and bioflavonoids. Because of these constituents, it has substantial antioxidantproperties.1 One study found that acerola significantly increased the antioxidant activity of soy and alfalfa.2 It is not clear, however, that this rather theoretical finding indicates anything of significance to human health. Other powerful antioxidants such as vitamin E and beta-carotene have proved disappointing when they were subjected to studies that could discern whether their actions as antioxidants translated into actual health benefits.

Like many plants, acerola has antibacterial and antifungal properties, at least in the test tube.3,4 However, no studies in humans have been reported.