Does It Work? Are Poinsettia Plants Poisonous?

BACKGROUND:Poinsettia plants are closely connected with Christmas. Their scientific name is Euphorbia pulcherrima, the second word is Latin for "the most beautiful".

The plant gets its English name from Joel Roberts Poinsett, an American physician, botanist and politician. He was the first US Minister to Mexico, and while there found the plant. He introduced it into the US in 1828 and from there it eventually made its way to Europe.

In Mexico, the plant is known as the " flor de Noche Buena" or Christmas Eve flower. The connection with Christmas comes from a story about a young Mexican child (or maybe two, depending on the version). She was too poor to afford a gift for Jesus's birthday, and could find only some weeds. She placed these at the manger in her village, only to be ridiculed by other children who had expensive gifts. Suddenly the weeds burst into beautiful poinsettias.

The story was a reminder that Christmas is about giving honour to a Child, not the cost of the gifts. The star-shaped leaves later came to represent the Star of Bethlehem, while their redness reflects the blood shed by Jesus at his crucifixion.

The Aztecs used poinsettias to make a red dye, and a remedy to reduce fevers. It also had a reputation for stimulating milk production and causing abortions. No research has been published on these uses. The focus instead has been on concerns about poinsettia’s toxicity.

EVIDENCE FROM STUDIES

In 1920, a two-year-old child was reported to have died in Hawaii after eating a poinsettia plant. That report has never been confirmed, but it helped to earn the poinsettia a place in a 1944 book called Poisonous Plants of Hawaii. The author, a physician, described it as highly poisonous. He later admitted that he had never confirmed the accuracy of his information.

Nevertheless, his claim was cited by one author after another, lending credence to the notion that poinsettias were poisonous, especially for children. Press reports occasionally reported further poisonings, and various groups in the US called for warning labels to be put on poinsettias. In the 1980s, poinsettias were banned in nursing homes in parts of the US because of these fears.

At the same time, numerous laboratory tests failed to identify any toxins of the plants. For ethical reasons, researchers could not give the plant to children just to measure its toxicity.

In the 1990s, a review of US Poison Control Centre records was conducted. More than 22,000 reports of poinsettia ingestion were examined, almost all involving children. No fatalities were found. Instead, in 92 per cent of the cases, no effects of any kind were observed. In 96 per cent of the cases, no treatment was given. Those who were treated with conventional responses did not fare any better than those who were not treated. A very small number of people had used the plant in suicide attempts. They were not successful.

It has been estimated that a 20kg child could probably eat 500 bracts without problems. This was after studies on animals found that giving them large amounts had no adverse effects. Not that this is recommended either!

PROBLEMATIC ASPECTS

While the oral ingestion of poinsettias has produced little verified harm, skin exposure has occasionally been problematic. People with latex allergy can also be allergic to poinsettia sap and leaves. While this usually produces skin irritation, two Japanese infants with latex allergy had severe allergic reactions after touching poinsettias. Those with latex allergy should avoid poinsettias.

RECOMMENDATIONS

The use of poinsettias to treat any condition is not supported by traditional or scientific evidence. However, their beauty and colour can lift the spirits, and remind us of the story that underlies this festive time. While there is no reason to be worried about little ones chewing on the leaves, it would be just as well to keep them out of reach anyway.

Dónal OMathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics. He is a senior lecturer in the School of Nursing, Dublin City University