The white mulberry leaf extract to be studied is an patented ingredient commercially available as Reducose.
The ingredient has undergone several research and clinical trials by British lifescience company Phynova, which is also the supplier of the ingredient.
Vixxol has been acting as Reducose’s distributor in the South Korean market since late 2022.
Speaking to NutraIngredients-Asia, Andy Kim, CEO of Vixxol, said that the aim of the trial was to provide scientific evidence for the company’s application of health functional claims with the South Korean regulator.
Currently, Reducose is used as a food ingredient and is unable to make health functional claims.
With clinical trial evidence, the company can then submit the trial results and apply for claims related to reducing postprandial blood glucose level with the Ministry of Food and Drug Safety (MFDS). The ingredient could also be the first mulberry leaf extract approved to make post-meal blood glucose reduction claims.
The trial, to be conducted from May 2025, is a 12-week double-blind, randomised, placebo-controlled study involving 100 individuals.
These individuals will need to fulfill certain recruitment criteria, including fasting blood glucose of between 100 and 125mg/dL and two-hour postprandial blood glucose of between 140 and 199 mg/dL.
During the trial, the intervention group will take 250mg of Reducose together with a meal each day for 12 weeks.
The key objective is to examine the effect that Reducose has on reducing post-prandial blood glucose level.
As such, the researchers will be measuring the changes in their blood glucose related biomarkers, such as the two-hour postprandial blood glucose level (OGTT), fasting blood glucose levels, and glycated haemoglobin (HbA1c) levels.
The study will also assess changes in insulin-related biomarkers, including the insulin resistance index HOMA-IR and serum insulin levels, and lipid profiles including total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides levels.
Of interest is also assessing the impact of Reducose on the body’s GLP-1 secretion levels, and other metabolic biomarkers such as adiponectin and leptin.
Blood glucose management awareness growing in South Korea
So far, Reducose is used in five health functional foods products in South Korea. These products are all from local Korean brands.
While some of the products use Reducose at the clinically effective amount of 250mg, some use it as a secondary ingredient at a lower dose.
Some of Vixxol’s partners using Reducose at the clinical dose include “Multidown Inner Maker” by E.L Rise and “Dang SSG-SSac Probiotics” by Balance Day. Both products are in the stick pack powder format.
Once Reducose is approved for making health functional claims by the MFDS, Kim believes that there would be more interest in using Reducose at the clinical dose, since the ingredient can make health claims.
Blood glucose management is a growing health functional foods sector in South Korea.
“Major boost will come after we have an official health claim from MFDS, which we expect to have in end of 2026 or early 2027,” said Kim, adding that the trial would take a year to complete, and the dossier review by the regulator would take about 180 days.
In fact, even without having the ability to make health claim, sales of Reducose has been increasing double digits yearly over the past three years.
“We began our partnership with Phynova in late 2022 and had our first product launched in early 2024, followed by four additional products in the same year.
“This year, we expect another two products to be launched and our volume to almost double from last year,” said Kim.
He believes that an increased awareness of metabolic health and a growing number of diabetic patients in South Korea are some of the key factors driving interest in supplements that support blood glucose management.
He pointed out that there are 3.8 million diabetic patients in South Korea and the number has been increasing by 4.5 per cent yearly since 2019.
As many as 15 million are at the pre-diabetic stage.
The market size of blood sugar management products in South Korea is also expanding, reaching 58.5bn won in 2023. The total market size of South Korea’s dietary supplement market said to worth 6.2tr won.
“As compared to the entire Korean dietary supplement market, blood sugar management is considered a small segment.
“However, if you look at the growth rate of the Korean dietary supplement market back in 2023, it actually plateaued and declined. Yet, the blood glucose management segment had grown double digit at 14 per cent,” said Kim.
The types of ingredients used have also evolved over the years, diversifying from “first-gen” ingredients such as banaba leaves and fibre to probiotics and mulberry leaf extract.
Across Asia-Pacific, Reducose is used as one of the main ingredients in products sold by Nestle.
Examples include the no-sugar Oolong tea containing 750mg of the extract launched in China last year, as well as a milk powder for supporting sleep and glucose management.
Australia’s eimele is another brand that also uses Reducose in its Calibrate Reds powdered drink for weight management. The product is also formulated with Morosil Moro Red Sweet Orange extract.
Other upcoming clinical studies
So far, Reducose is backed by findings from 11 clinical trials, with four more clinical studies to be conducted this year.
In the UK, Phynova is commencing the REMET Study in partnership with Oxford Brookes University, and backed by a competitive grant awarded by Innovate UK.
Also a 12-week, double blind, placebo-controlled study, the trial will evaluate blood glucose parameters, insulin response sensitivity, body composition parameters, blood lipids, blood pressure, satiety, adiponectin, leptin, inflammatory markers, and the microbiome.
Another trial, known as the ClariPhy study, will evaluate the impact of Reducose on cognitive function, energy, sleep, mood/emotional distress over a six-week period.
In the US, a study will be conducted on menopausal women. Known as the Calm-R study, it will assess at whether Reducose can help with menopausal symptom management, as many of the symptoms have a root in glucose/insulin responses, according to Andrew Gallagher, global head of science at Phynova.
According to a trial funded Nestle Health Science, a company which is using the ingredient in several of its products, showed that the supplementation of Reducose could reduce postmeal blood glucose spike.
The study was conducted on its product Nutren GlucoSmart sold in Malaysia. The product also contained fibre, vitamin D, and chromium.
The findings, published in Diabetes Therapy, showed that individuals supplemented with Reducose had their blood glucose spikes lowered by 15 to 20 per cent as compared to the control group.
The ingredient is said to work by blocking enzymes in the upper digestive system that break down sucrose and carbohydrates into glucose for about an hour.
With fewer numbers of sucrose and carbohydrates broken down, the process lowers post-meal blood sugar and insulin excursions.
