Assertion: comfrey | /r/ObjectUse | used as food
Facets:
value: in the past
type: TEMPORAL
value: from earthworms
type: OTHER
Source sentences:
text: From earthworms to fish to birds to mammals and humans — Comfrey is used as food and medicine.
text: Although comfrey has been used for food in the past, recent evidence suggests that it contains carcinogenic compounds and can cause liver damage.