Knowledge of medicinal plants in danger as languages die out | Plants
Knowledge of medicinal plants is at risk of disappearing with the extinction of human languages, a new study has warned.
Indigenous languages contain vast amounts of knowledge about the ecosystem services provided by the natural world around them. However, more than 30% of the 7,400 languages on the planet should disappear by the end of the century, according to the UN.
The impact of language extinction on the loss of ecological knowledge is often overlooked, said the study’s lead researcher Dr. Rodrigo Cámara-Leret, a biologist from the University of Zurich. “Much of the attention is on the extinction of biodiversity, but there is a whole other picture which is the loss of cultural diversity,” he said.
His team examined 12,000 medicinal plant services associated with 230 indigenous languages in three regions with high levels of linguistic and biological diversity – North America, the northwest Amazon and New Guinea. They found that 73% of medical knowledge in North America was in a single language; 91% in the northwest of the Amazon; and 84% in New Guinea. If languages disappeared, so would the medical expertise associated with them. The researchers expect their findings in these regions to be similar in other parts of the world.
“The loss of language will have a more critical impact on the extinction of traditional knowledge of medicinal plants than the loss of the plants themselves,” Cámara-Leret said.
The areas with the most endangered languages are in the northwest Amazon, where 100% of this unique knowledge is supported by endangered languages, and in North America, where this figure is 86%. In New Guinea, 31% of languages were at risk. The anticipated loss of linguistic diversity “would significantly compromise humanity’s ability to discover medicines,” according to the article published in PNAS.
This knowledge includes the use of the latex of the plants to treat fungal infections, the use of the bark to treat digestive problems, the fruits for respiratory ailments, as well as natural stimulants and hallucinogens. “The list goes on and on, it’s quite impressive,” Cámara-Leret said. “Even the best plant taxonomists are amazed at the extent of indigenous cultures’ knowledge, not only of plants but also of animals and their interrelationships.”
It is impossible to know what has already been lost. More than 1,900 of the languages spoken now have fewer than 10,000 speakers and the UN has declared 2022-32 the International Decade of Indigenous Languages in recognition of this problem.
Jordi Bascompte, ecologist from the University of Zurich and second author of the paper, said European medical knowledge could represent the “tip of the iceberg”. Although many drugs are based on synthetic compounds, there may be many more chemical compounds provided by plants that could unlock the potential for new treatments. “Any idea, no matter where it comes from, can be useful,” he said.
The paper did not examine the extent to which medicinal services are considered effective in the Western sense, although researchers say that in many cases plants have been shown to be effective.
Much of the world’s linguistic diversity is safeguarded by indigenous peoples whose culture and livelihoods are threatened as barriers between groups are broken down. Unlike societies where information was written down in books and computers, most Indigenous languages transmit knowledge orally.
Government programs to boost language transmission, bilingual education and interest in cultural heritage would help communities retain their linguistic diversity, Cámara-Leret said. But the medical aspect is just one of many reasons to promote the conservation and diversity of languages around the world, he added.
University of Kent anthropologist and conservationist Dr Jonathan Loh, who was not involved in the research, said he was surprised at the degree of linguistic uniqueness in knowledge of medicinal plants. He has previously spoken of the parallels between linguistic and biological diversity, commenting that these have evolved in remarkably similar ways and that both face an extinction crisis.
He said it was important, however, not to focus on utilitarian arguments for the conservation of languages, cultural diversity and biodiversity.
“There may be valuable knowledge about medicines unknown to Western science contained in these languages, and that may be true to some extent, but that’s not the most important reason for keeping them,” said he declared. “Each indigenous language and culture is a unique evolutionary lineage that once lost is lost forever.”