- A new study has found that concentrations of essential minerals inside rhino horns are too low to provide consumers with any health benefits, questioning their use in traditional Chinese medicine.
- The scientists also revealed that rhino horns contained potentially toxic minerals; the lack of quality control testing and regulatory oversight makes it even more pressing to address the sales of rhino horn derivatives for consumption.
- Researchers say that efforts to reduce consumer demand for rhino horn products must run in parallel with protection.
Fancy a taste of your own toenails? That’s what vendors in Vietnam or China could say when offering powdered rhino horn. This coveted “trophy” is made up of keratin, the same structural protein as human nails and hair. And a new study in Scientific Reports finds it about as nutritious, despite claims to the contrary, underlining the scientific consensus that consuming rhino horn has no real health benefits.
In parts of Asia where traditional Chinese medicine is deeply rooted, people have been consuming rhino horn for millennia. Medical texts from the 16th century show that rhino horn has been touted as a cure for ailments ranging from fever and rheumatism to snakebites and even demonic possession.
“Rhino horns have a long history of being sold as part of TCM [Traditional Chinese Medicine] by doctors who … believe that rhino horns … will dispel heat and clear toxins from the body,” said study lead author Terri Roth, head of the Center for Conservation and Research of Endangered Wildlife (CREW) at Cincinnati Zoo & Botanical Garden in the U.S.
Yet the new research revealed that while beneficial minerals were present in rhino horn, they only occurred in very low concentrations — not enough to impart any kind of benefit.
The trade in rhino horn has long been the main threat to rhino populations in Africa and Asia, where poachers kill the animals and cut off their horns with a machete or chainsaw — sometimes while the animal is still alive. This makes understanding the components of rhino horn all the more important.
‘Implausible’ health benefits
To get at the heart of what rhino horn consumers are ingesting, the study’s authors quantified the minerals in shallow and core samples of horns from captive white (Ceratotherium simum) and black rhinos (Diceros bicornis), both native to sub-Saharan Africa. The white rhino is near-threatened, and the black rhino is critically endangered.
“The few reported studies on rhino horn’s medicinal properties focused primarily on antipyretic [fever-reducing] activity, and published results are contradictory,” the researchers write, warning of the recent expanded use of rhino horns to treat severe diseases for which medical care may be needed.
After examining the horn samples for various minerals like sodium, sulfur, copper and iron, the scientists found both essential and potentially toxic elements present. Of the 12 essential minerals they detected, concentrations were substantially lower than in a much cheaper daily vitamin. As such, the health benefits of eating rhino horn appear “implausible,” their study reads.
Toxic minerals, too, were found in such low concentrations that they likely wouldn’t pose a major human health risk at typical doses. But there’s a caveat.
Roth’s team found that samples harvested from the exterior surface of the horn contained higher concentrations of many potentially toxic minerals and metals, in line with the levels found in the rhino’s environment — particularly in the soil. Soil composition varies greatly from one location to another, making it hard to predict the components that adhere to rhino horns.
Roth cited arsenic as an example. In what she calls “clean” rhino horns, arsenic concentrations likely wouldn’t be harmful to human health. In soil-contaminated samples, however, they could exceed the levels allowed by regulators of human food and pharmaceuticals.
“You may be paying a lot of money for a sample containing dirt,” she said.
Wild rhino horns would contain even greater amounts of contaminated material than the captive ones used in the study, pointed out Olivia Smith, communications manager at U.K.-based NGO Helping Rhinos. And given its current illegality, there’s no quality control testing or regulatory oversight of horn-based products, making consuming rhino horn a perilous bet.
“Any medicine, either botanical, mineral or animal products, if used improperly, could cause harm to our patients,” commented Lixing Lao, the president of Virginia University of Integrative Medicine and co-chair of the Coalition of Wildlife Protection in TCM.
“The contribution of this study brings us awareness about this product,” he added. “For consumers who have no knowledge of Chinese medicine, it could pose more risks and be harmful if they take these products by themselves.”
From status symbol to ‘handful of dirt’
Demand for rhino horn is driven nearly exclusively by Asian countries, predominantly Vietnam and China, where demand fuels poaching on the other side of the globe or, as Lao summed it up: “Endangered animal issue is a global problem. If an extinction of animals happened in one place, it would affect the other part of the world.”
In 2022, the number of rhinos across Africa increased by 5.2% to 23,290, but poachers slaughtered at least 561 African rhinos, including 448 in South Africa alone. The country, home to more rhinos than any other, saw the poaching figure rise to 499 in 2023.
“Currently, all international media blame TCM as the one that’s responsible for the extinction of endangered animals in the world,” Lao said, flagging potential reputational damage “if the TCM community does not act to protect the endangered animals.”
Globally, the persistent decimation of rhinos has led to the extinction of multiple subspecies. Today, the northern white rhino (Ceratotherium simum cottoni) is functionally extinct, with just two females left. Both the Javan and the Sumatran rhinos are listed as critically endangered, with likely little more than 50 individuals left each. Recently, investigators in Indonesia arrested poachers accused of killing around a third of the world’s Javan rhinos. The biggest threat to the Indian rhinoceros (Rhinoceros unicornis), currently listed as vulnerable, is also poaching for its horn.
For Smith, Africa’s rhino statistics “certainly are a mixed bag.” But unlike for the Javan and Sumatran rhinos, she’s optimistic that with international support, “the African rhino species have a sustainable future in their natural habitats.”
Dave Balfour and Sam Ferreira, respectively the chair and the scientific officer of the African Rhino Specialist Group at the IUCN, the global wildlife conservation authority, told Mongabay in an email that even though poaching persists, the future of African rhinos looks more upbeat.
“Fortunately, rhinos breed well in Africa if given the chance,” Roth said. “However, it is not yet time to let down our guard in Africa or Asia.”
“Sadly, there are buyers who are now … banking on the extinction of the species so that they may capitalize” — the rarer the animal becomes, the more value its horns hold, Smith explained. “To combat this will take an entirely different approach, in which all commercial value must be removed from the horn.”
Increasingly, wealthy consumers are buying rhino horns not as a fever medicine, but as a mythical detoxifier for an excessive lifestyle, or as a status symbol, making their consumption “totally disconnected from the desire to treat illness,” Roth said.
On the other hand, “if the gift of rhino horn is equated with a handful of dirt, perhaps people will find something more suitable when trying to please or impress someone else,” she added.
Reducing consumer demand to reduce poaching
Conservationists have deployed many creative initiatives to deter rhino poaching. Researchers in South Africa have recently injected radioactive material into rhino horns, so they can be picked up by radiation detectors at international border crossings.
Dehorning is another solution, where a rhino is regularly tranquilized and its horn cut off to make it less valuable as a poaching target. But even this doesn’t guarantee immunity to poaching. Besides, rhinos need their horns to assert dominance, defend themselves, steer their calves and forage in compact soils for hidden grasses.
According to Roth, it’s best to have many actions in play, given that the wildlife conservation landscape is changing constantly.
“Protecting wild rhinos from poachers is an absolute priority, but in so doing, we are only treating the symptoms of the problem,” she said.
Some organizations have therefore made tackling consumer demand for horns a priority, but it’s a strategy for the long haul.
“Changing long-held traditional beliefs takes years, sometimes generations, so while these longer-term efforts are put into action, it is vital we maintain anti-poaching efforts to buy the rhino enough time for demand reduction strategies to take effect,” Smith pointed out. “Without the immediate work being done to protect rhinos, there would be none left by the time demand reduction programs saw results. And alternatively, without the long-term goal of ending the demand, we will be stuck in a never-ending loop of intensive, and expensive, rhino protection.”
Smith said that she wishes more people would make the link between the live rhinos grazing peacefully in the wild and the horn powder, but added that it isn’t realistic.
“As long as the use of rhino horn is legitimized by governments within countries that have the highest demand for rhino horn, not only will there be cracks in the market for poached horn to slip through, but the power of messaging around not using horns will be diluted,” Smith pointed out.
Roth explained that she hopes her study will make people think twice about rhino horn consumption, but added that she’s “not naive enough” to think that scientific results will substantially sway public opinion. “In today’s world, people choose to believe science that supports what they want to do while disregarding that which doesn’t.”
Still, if there’s a chance that the absence of health benefits overturns even just a few people’s beliefs, scientists know that they ought to share it.
Banner image: Targeting demand for rhino horn-based products must complement efforts to protect rhinos from poaching. Image by Geranimo via Unsplash.
Citation:
Roth, T. L., Rebolloso, S. L., Donelan, E. M., Rispoli, L. A., & Buchweitz, J. P. (2024). Rhinoceros horn mineral and metal concentrations vary by sample location, depth, and color. Scientific Reports, 14(1). doi:10.1038/s41598-024-64472-z.
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