Tea is the second-most popular beverage in the world after water, but scientific research is beginning to show that it's not just good for drinking. Green tea, an unfermented form of the leaf, is particularly promising for its health benefits, and more than 150 clinical studies have tried to find out whether green tea has positive effects on the skin.
Anti-Aging
Green tea compounds have significant antioxidant and anti-inflammatory properties, with studies suggesting green tea extracts can help prevent ultraviolet radiation damage. Researchers at Emory University's Department of Dermatology in 2005 treated women who had moderate photo aging with either a combination regimen of 10 percent green tea cream and 300 mg twice-daily green tea oral supplement or a placebo for eight weeks. The women receiving the green tea showed significant improvement in the elastic tissue of their skin. In 2009, German researchers used green tea-filled cotton pads placed on skin in human subjects for 20 minutes a day before treating the skin with an array of light-emitting diodes. The combination of green tea plus the light therapy produced in one month the same rejuvenated skin, reduction in wrinkle levels and juvenile complexion that previously had taken 10 months of light therapy.
Psoriasis
A study published in the August 2007 issue of Experimental Dermatology investigated green tea's effects on psoriasis, a skin condition that causes thick, silvery scales and itchy, dry, red patches. The researchers found that topical application of a 0.5 percent solution of green tea extract significantly reduced the symptoms of epidermal pathology in mice with flaky skin, suggesting that the tea therapy may be beneficial in the treatment of psoriasis and similar skin diseases.
Skin Cancer
Skin cancer is the most common type of cancer in the United States, according to the Centers for Disease Control and Prevention. Several studies have looked at the possibility of green tea preventing or treating skin cancer. A study at the University of Alabama at Birmingham Department of Dermatology, published in the February 2010 issue of Cancer Prevention Research, showed that mice treated with green tea extract exhibited faster repair of UV-induced DNA damage. A study at the University of Maryland School of Medicine in 2009 found that green tea polyphenols reduced skin tumor cell survival by influencing the cell's regulatory mechanisms.
Sun Protection
Because skin cancer is often caused by overexposure to the sun's UVA and UVB rays, scientists and cosmetics companies are constantly trying to find ways to improve sunscreen products. A study published in Skin Research and Technology in 2009 treated human subjects with a sunscreen containing 2 percent to 5 percent green tea extracts prior to sun exposure, with later skin biopsies showing that the sunscreen exhibited marked photo protective effects.
Wound Healing
Scientists at Korea University's College of Life Sciences and Biotechnology investigated the application of chitosan green tea polyphenol complex on wounds. The complex exhibited enhanced healing properties on incision wounds by increasing the breaking strength of the wounds. In excision-type wounds, the green tea complex hastened the period of cell growth in the epithelial, or outer, layer of the skin.
References
- Journal of the American Academy of Dermatology: Green Tea and the Skin
- Skin Research and Technology: Protective Effects of Green Tea on Photoaging and Photommunosuppression
- Chinese Journal of Traumatology: Green Tea Polyphenol Complex as Compound for Wound Healing
- Photomedicine & Laser Surgery: Green Tea and Red Light--a Powerful Duo in Skin Rejuvenation
- Cancer Prevention Research: Green Tea Polyphenols Prevent UV-induced Immunosuppression
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