“I’m honoured to be part of a meaning ful project that seeks to make a lasting impact on our community through research. I’m hopeful that Hong Kong will once again reclaim its title as the Pearl of the Orient.”— Dr Wa-tat YAN
For centuries, pearl powder was treasured as something more valuable than a jewel. Crushed into the finest dust, it was believed to heal wounds, and cleanse the body of toxins. But did it truly work? Without science, the answer remained a mystery. In 2016, a research team from the School of Biological Sciences set out with global partners and local pearl farmers to put those age-old claims to the test. Their findings are striking: pearl powder can indeed help the body reduce heavy metals and protect vital organs.
In the process, they also gave new hope to Hong Kong’s pearl oyster industry, breathing life into a heritage once thought lost.
A Heritage of Pearls in Hong Kong
Once abundant in Hong Kong’s coastal waters, the Pinctada fucata, a pearl oyster prized for its beauty and medicinal value, thrived in the region’s warm seas and sheltered shores. Renowned for their quality, these pearls were treasured as far north as Peking, their value so great that historical records note that troops stationed in Tai Po to harvest and guard them. Sai Kung, too, was famed as a fertile ground. Today, however, this centuries-old legacy faces mounting challenges. Warming seas and rising acidity are making it harder than ever for oysters to form pearls.
“Pearl farming was attempted in Hong Kong back in the 1960s, but those early efforts eventually faded,” says Dr Wa-tat YAN, a PhD graduate from the School of Biological Sciences (SBS). “My research focuses on pearl oyster farming, and I want to revive that attempt by making use of the many idle fish rafts around Hong Kong.”
Together with Professor Billy Kwok-Chong CHOW, Chair Professor of Endocrinology at the SBS, the two now lead a research team at SBS dedicated to reviving Hong Kong’s pearl oyster heritage while exploring its modern scientific potential.
In the past, pearls formed naturally in the wild, but today most are cultivated. The process begins when researchers insert a small nucleus, usually from a freshwater mussel shell, into the pearl oyster. Over time, the oyster coats the nucleus with nacre, the lustrous substance also known as mother-of-pearl, gradually forming a pearl.
“The nacre layer is the key,” explains Chow. “It’s rich in calcium carbonate, proteins and amino acids, all the essential materials that give pearl powder its medicinal value in Chinese medicine.”
To help oysters adapt to rising sea temperatures, the team is training local fishermen in pearl oyster farming, collaborating with scientists in China to identify climate-resilient varieties, and exploring tropical species better suite to warmer waters.
“After about a year of cultivation, the pearls are harvested. At the farm, suitable shells are selected and taken to the lab, where they are cleaned, examined, and ground into powder for analysis.”
HKU researchers and fishermen collaborate on fish rafts to revive pearl oyster farming.
Putting Tradition to the Test
Once the nacre was processed into powder, the team put it to the test. Using laboratory rats, they conducted in vivo experiments to model exposure to heavy metals, specifically mercury, lead, and aluminium, followed by treatment with pearl powder.
The results are compelling. The powder consistently lowered the concentration of these metals in the blood, regardless of dosage. It aids in flushing the toxins out through urine and faeces, and more importantly, lessens signs of damage in the liver and kidneys, the organs most vulnerable to metal poisoning. It is evidence that echoes the claims of ancient texts.
“The results of our experiments have been nothing short of exciting!” says Yan. “The depth and brilliance of traditional Chinese medicine continue to amaze and inspire us.”
The promise of pearl powder does not end with proof. Building on their discoveries, the team has secured three patents and intellectual property rights to protect new applications, laying the groundwork for future collaboration with industry.
“Leveraging these patents, Dr Yan and I have established a startup, the Pearl Power Research Institute, so we can develop the technology not only for pearl oyster farmers, but also for Hong Kong,” says Chow.
“In a significant move, local fishermen have joined our HKU start-up as shareholders, enabling them to benefit directly from our research,” says Yan with excitement. “Our company is also committed to sourcing oyster shells exclusively from accredited local fish farms. We believe this initiative will not only increase fishermen’s incomes but also provide a sustainable and successful model for collaboration between academia and the primary sector.”
The team is now experimenting with various formulations for supplements and skincare products. If all goes to plan, they aim to launch three product lines within a year, focusing on detoxification, anti-oxidation, and gut health, all in easy-to-take pill form.
“I’m optimistic that we cannot only revive pearl oyster farming in Hong Kong, but also build a strong industry around pearl oyster powder,” adds Yan.
What began as an ancient remedy is now being reshaped by modern science. Through their work, the team is demonstrating how tradition and innovation can coexist, opening the door to new therapeutic possibilities and a renewed future for Hong Kong’s pearl oyster industry.
Video to learn more about the research
(video credit: HKU Knowledge Exchange Office)
Professor Billy CHOW
|  | Dr Wa-tat YAN
|  |
| < Previous | Next > |