The Food and Drug Administration (FDA) has issued a warning advising consumers to avoid consuming herbal teas containing star anise, following reports that at least 40 people, including 15 infants, became ill after drinking teas brewed with the fruit.
According to the FDA, the cases have occurred over the past two years and symptoms have included serious neurological effects, such as seizures, as well as vomiting, jitteriness and rapid eye movement. All the affected individuals recovered, however, without complications.
While the FDA did not identify the part of the plant that was used in the 'brewed teas', it appears that at least some of the reported cases were associated with the plant's flowers. It is generally only the dehydrated fruit of star anise that is found in commerce.
The agency added that it had also been unable to identify the particular species of star anise that was used by the affected individuals. The true star anise - Illicium verum - identified by the FDA as 'Chinese star anise', is generally recognized as safe (GRAS) for use in foods. However, other species, such as Japanese star anise or shikimi - I. anisatum - and native North American species such as Florida anise - I. floridanum - are known to be toxic.
Scientists have reported notable morphological differences between the fruit of true star anise and that of Japanese star anise when these articles are examined in whole form. In addition, the composition of the volatile compounds in these two species is said to differ considerably.
The non-toxic I. verum species has been found to contain significant amount of anethole - a sweet naturally occurring oil often used in the alcoholic beverage industry - while safrole - a carcinogen banned by the FDA - is either absent or is found in only trace amounts. I. anisatum on the other hand has been found to be high in safrole.
No mention was made of dietary supplements containing star anise and the American Herbal Products Association (AHPA) stated that it has been informed that none of the reported cases have been associated with dietary supplement products.