Ergot is a disease of grains caused by a fungus known as Claviceps purpurea. The fungus produces reproductive structures called sclerotia which replace some of the normal kernels of the grain and are poisonous. Each sclerotium is a small, compact mass of fungus with a tough, dark purple or black covering. There are many reports describing the dangerous and even fatal effects of eating food contaminated with ergot sclerotia, which contain toxic alkaloid chemicals. However, some of the alkaloids have medical benefits when used in pure form and in very small doses.
Ergotism is the name used for poisoning by ergot sclerotia. There are two types of ergotism: convulsive ergotism and gangrenous ergotism. Symptoms of convulsive ergotism include headaches, nausea, vomiting and diarrhea followed by muscle spasms, tingling, numbness, hallucinations, delusions and seizures. In gangrenous ergotism, blood vessels going to the arms, legs and ears constrict, reducing blood flow. As a result, body tissue may die and the victim may experience burning pain. Fingers, toes and ear lobes may be destroyed, turn black and fall off, and in extreme cases tissues in the arms and legs may die too. Ergotism affects humans who eat grain products containing material from ergot sclerotia, and also affects animals that graze on contaminated grains.
Ergot often occurs in rye, which was a commonly eaten grain in Europe in the middle ages. People at this time thought that the black rye kernels were unimportant, and ground them with the rest of the rye grain to make flour for bread. As a result, episodes of ergotism were common. Gangrenous ergotism used to be called Saint Anthony’s Fire. The “fire” was the burning sensation that the sufferers experienced. Monks built hospitals in the name of Saint Anthony to help the victims of the disease.
Two beneficial alkaloids made by the ergot fungus are ergotamine and ergonovine. Ergotamine acts as a vasoconstrictor (a substance which constricts, or narrows, blood vessels). This is why ergotamine has been used in the past to reduce blood flow from the uterus after a baby is born. Today ergonovine is used to prevent bleeding after childbirth or a miscarriage.
The main use of ergotamine today is to treat some cases of migraine. Researchers know that during a migraine attack blood vessels in the head are expanded and there is an abnormal production of chemicals around the blood vessels, but migraines are a poorly understood disorder. Ergotamine has several effects in the body and may help to relieve a migraine not only by constricting blood vessels in the head but by other methods as well.
A neurotransmitter is a molecule that either transmits a nerve impulse from the end of one neuron (nerve cell) to the start of the next neuron, or stops the nerve impulse from being transmitted. Neurotransmitters are released from the first neuron and join to receptors on the second neuron in order to exert their effect. Ergotamine affects the activity of specific neurotransmitters at the receptors on neurons.
A doctor’s instructions must be followed carefully when taking ergotamine, since there is a slight chance that it can decrease blood flow to the hands, feet or other body areas. The risk is increased if ergotamine is used in combination with certain other medications. Ergotamine use needs to be spread out; the medication isn’t supposed to be taken regularly, so it’s not prescribed for a person who has frequent migraines. In addition, ergotamine isn’t prescribed for pregnant women since it causes uterine contractions.
Ingesting an entire ergot body, or a section of the ergot body, is dangerous. Luckily, modern farmers are well aware of the dangers of the ergot fungus to both humans and farm animals and are vigilant with their crops and with the grasses that their animals eat. However, even today there are occasional reports of people or animals getting sick from eating grains or grain products contaminated with ergot fungus.