Broad bean-Vicia faba L.-Poisonous plant

Broad bean

General poisoning notes:

Broad bean (Vicia faba) is a cultivated plant that is grown occasionally in Canada. The beans are used as human food and are being evaluated as a protein supplement for livestock. Broad beans are not poisonous to humans in the conventional sense, but they cause favism in susceptible individuals. These individuals have a genetically transmitted, male sex-linked deficiency to the enzyme glucose-6- phosphate dehydrogenase. Certain groups such as Oriental Jews, Mediterranean Europeans, Arabs, Asians, and blacks may have the deficiency. The disease can cause death in severe cases. Livestock, including swine, have also been poisoned from ingesting high quantities of beans. Dietary broad beans can also cause metabolic problems in poultry. It is important to note that nonsusceptible persons who eat broad beans are not at risk (Kingsbury 1964, Cooper and Johnson 1984, Cheeke and Schull 1985, Roy and Spencer 1989).

Nomenclature:

Scientific Name: Vicia faba L.

Vernacular name(s): broad bean

Scientific family name: Leguminosae

Vernacular family name: pea

Geographic Information

Plant or plant parts used in or around the home.

Notes on Poisonous plant parts:

Susceptible individuals who ingest raw or partly cooked seeds and inhale pollen can be poisoned (Cooper and Johnson 1984).

Toxic parts:

Pollen, seeds

Notes on Toxic plant chemicals:

Two glycosides, convicine and vicine, and their respective aglycones, isouramil and divicine, are implicated in favism. In individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, a cycle is prevented that would normally reduce the oxidants so that they cannot attack the red cell membrane (Cheeke and Schull 1985).

Toxic plant chemicals:

convicine
vicine

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Chickens

General symptoms of poisoning:

Egg production, reduced

Notes on poisoning:

Unprocessed broad beans contain factors that lower the rate of chicken growth and alter the size of liver and pancreas. Dietary broad beans have a marked influence on the metabolism of laying hens. Vicine, which is thermostable, causes a reduction in the number of ova, in egg weight, in fertility, and in egg hatchability (Cheeke and Schull 1985).

Humans

General symptoms of poisoning:

Abdominal pains, collapse, death, dizziness, Heinz bodies, hemoglobinuria, icterus, jaundice, methemoglobinemia, temperature, elevated, vomiting.

Swine

General symptoms of poisoning:

Abdominal pains, appetite, loss of constipation, depression

Notes on poisoning:

Broad beans are used as animal feed as silage or are added to feed. However, in one case in Poland, pigs were poisoned after eating broad beans as one-third of their diet. Symptoms included depression, reduced activity, flatulence, and constipation. Postmortem examination revealed inflammation of the alimentary tract and pale yellow liver and kidneys (Cooper and Johnson 1984).