Like Americans who eat right and take herbal supplements to improve their health, many Pacific Islanders drink a beverage derived from the kava plant. However, considering the potential side effects of large amounts of kava, researchers are currently wondering just how these peoples can tolerate the plant.

A study published in the journal Chemical Research in Toxicology recently examined the contents of kava, which is an herb or pepper that has been used as a traditional medicine for centuries by people of the South Pacific.

The root of the plant, also known as Piper methysticum, is the part that some Pacific Islanders still render into beverages, which they drink during cultural rituals. The study notes that large amounts of kava extract can be unhealthy, but apparently the Islanders are all but immune to the effects of the plant.

Likewise, the authors conducted a review of 85 articles on kava and found no consensus on what it is about the plant’s biochemistry or its preparation that makes it potentially toxic.

Individuals who want safe herbal supplements may consider taking more common varieties, like saw palmetto for or ginkgo biloba for memory.