During the first world war, the British government was looking for ways to help people stretch their limited food supplies. It found pamphlets from a noted 19th-century herbalist who said rhubarb leaves could be used as a vegetable along with the stalks.
The government duly printed its own pamphlets advising people to eat rhubarb leaves as a salad rather than throwing them out. There was one problem: rhubarb leaves can be poisonous. People reportedly died or became ill.
