Certain components in green tea have significant antioxidant properties and have been used in skin care preparations to treat aging skin. This study was performed to evaluate the effects of a combined treatment of oral green tea supplementation and skin cream on aging skin. For this study, 40 women were divided into two groups and given either green tea supplements or placebo for eight weeks. It was seen that those taking and applying the green tea supplements had improvement in elastic tissue content. However, clinically significant changes were not demonstrated.
Green tea contains certain compounds with well-documented anticancer, anti-inflammatory and antioxidant properties. These components also help in the regulation of certain proteins involved in skin damage and disease. It has been shown experimentally that the components in green tea could stimulate the aged skin cells to renew cell division. Although previous clinical studies have highlighted the use of green tea as mentioned above, no studies involving a sizable population have been conducted. This study is one of the very few to investigate both oral and topical application of a green tea supplement and study their possible effects on aging skin.
* This study involved 40 women with moderate aging of skin. They were not on any medication that could moderate the skin tone.
* There were two groups. Those in the intervention group were given 300 mg green tea supplements twice daily and were asked to apply a cream with 10 percent green tea extract to the face and arms, plus and use a cleanser and sunscreen. The placebo group was given the same without the green tea extracts. The study was done for eight weeks.
* Both groups were asked to stop using any new medications, including nonstudy topical treatments, or any new nutritional supplements and no other topical products on the treatment areas.
* Clinical examination of the skin and skin biopsies, at the beginning of the study and at the end, helped in the assessment of the influence of green tea.
* There were no significant clinical differences in both the groups when assessed by a physician.
* However, the biopsies obtained after the study showed improvements in the content of elastic tissue in the group treated with green tea extract.
* Many patients found the creams containing 10 percent green tea extract to be too drying and complained of irritation.
As both oral green tea supplements and topical creams were used in this study, it was not clear which mode of delivery was responsible for the improvement of skin. Neither group received only one or the other type of treatment. The duration of this study was short and the authors suggest a prolonged study for better results.
Although the study period of eight weeks was insufficient for this study, significant cellular differences were observed in those participants treated with green tea extracts. There was an increase in the content of elastin, a substance that gives elasticity to the skin and reduces wrinkles. This is also concurrent with the antioxidant properties of green tea extracts. As seen in this study, the eight-week duration could not have been sufficient for visible skin changes, although cellular changes were seen. Further studies involving more participants and a longer duration are needed to demonstrate the visible changes of green tea extracts on skin.
For More Information:
Double-Blinded, Placebo-Controlled Trial of Green Tea Extracts in the Clinical and Histologic Appearance of Photoaging Skin
Publication Journal: Dermatologic Surgery, 2005
By Annie E Chiu, MD; Joanna L Chan; Emory University, Atlanta, Georgia, Nu Skin International, Inc., Provo, Utah and Stanford University, Palo Alto, California and Harvard Medical School, Boston, Massachusetts