Data published in Nutrients indicated that consumption of 300 mg per day and 600 mg per day of the Hydrangea extract for 12 weeks led to significant improvements in skin wrinkles, skin hydration, and skin texture, compared to placebo.
In addition, the statistically significant improvements in skin elasticity compared to placebo at the end of the three-month intervention period were only seen for the higher dose.
“Our randomized, double-blinded, placebo-controlled study demonstrated that oral WHS [hot water extract of Hydrangea serrata leaves] supplements produced significant anti-aging effects. Therefore, WHS has potential as a dietary supplement to protect against skin aging in the health functional food, targeting systemic factors regulating skin appearance,” wrote the researchers.
Building the science
According to the researchers, Hydrangea serrata leaves have been consumed as a tea and as medicine in the cultures of Korea, China and Japan. Products formulated with Hydrangea root are already commercially available in the US, mostly positioned to support urinary healthy.
The new study adds to earlier research from the same group, which investigated the potential skin health benefits of the Hydrangea serrata leaves extract in human cells and hairless mice (Han et al. Nutrients 2019, 11(3), 533).
Researchers from the Department of New Material Development at South Korea-based COSMAXBIO, which develops and provides ingredients to cosmetics brands around the world, continued to be involved in the research, which was led by scientists from Kyung Hee University in Seoul.
The South Korean researchers recruited 151 people and randomly assigned them to one of three groups: The WHS at 300 mg per day, WHS at 600 mg per day, or placebo for 12 weeks. Skin measures were taken after weeks four, eight, and 12 weeks.
The data showed that facial wrinkles showed that both Hydrangea groups experienced significant reductions in crow’s feet around the eyes after eight and 12 weeks, compared to placebo.
“[T]he improvement in skin wrinkles following WHS intake is consistent with the previous study, in which the expression of MMPs (MMP-1 and MMP-3) is downregulated by oral WHS administration in UVB-irradiated mice, thereby increasing the collagen content in the skin and reducing wrinkle formation,” wrote the researchers.
Moreover, both Hydrangea groups experienced statistically significant improvements in skin hydration after 12 weeks, compared to placebo.
Only the 600 mg per day dose led to significant improvement in overall elasticity, net elasticity, and ratio of elastic recovery to total deformation, compared to placebo.
“Although the underlying mechanisms by which WHS improves skin wrinkles, hydration, elasticity, texture, and roughness were not investigated in this clinical trial, we suggest that the WHS supplement may have a positive effect on collagen decomposition based on the previous in vitro and in vivo studies,” wrote the researchers.
“Additionally, these preventive skin aging effects of WHS may be mediated through the anti-oxidative activities of hydrangenol, an active-constituent of H. serrata.”
Importantly, the researchers added that the Hydrangea extract was found to be safe for human consumption at the dosage studied, noting that data from acute toxicology studies with rats have showed that oral consumption of this hot water extract of H. serrata leaves did not produce toxicity or mortality up to 5,000 mg/kg.
2020, 12(6), 1588; doi: 10.3390/nu12061588
“Oral Intake of Hydrangea serrata (Thunb.) Ser. Leaves Extract Improves Wrinkles, Hydration, Elasticity, Texture, and Roughness in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study”
Authors: Da-Bin Myung et al.