Green tea (Camellia sinensis) is the most consumed tea around the world. Could this be down to it’s youth promoting, anti-ageing constituents?! The tea contains naturally occurring compounds called polyphenols, which act as potent antioxidants. It’s produced from fresh leaves in a way that preserves the antioxidant potential unlike black tea where a high degree of oxidation (Destroying antioxidants) occurs.
Catechins (pronounced: ca-teh-kins) make up some of polyphenols present in green tea and the most abundant one being EGCG (epigallocatechin-3-gallate), which has been extensively researched in relation to skin health and provides many benefits when consumed as a drink or topically applied
A primary cause of skin aging is the imbalance between ROS (reactive oxygen species)/ DNA damaging free radicals and level of antioxidants present.
How does EGCG work on skin health?
- EGCG has been widely studied for many characteristics that promote skin health such as antioxidant and anti-inflammatory activity.
- Studies have shown that EGCG can up regulate the production of hyaluronic acid (molecule that keeps skin hydrated) in keratinocytes (skin cells), thereby providing moisture to the epidermal layer and maintaining a firm skin barrier.
- It inhibits the degradation of hyaluronic acid in the epidermis and increase the hydration retention capacity of the skin barrier.
- It can inhibit the enzymes collagenase (Breaks down collagen) and elastase (breaks down elastin).
- It has the ability to scavenge and neutralise free radicals that cause skin ageing!
- It reduces sebum production and inhibits growth of p-acnes (the bacteria responsible for acne)
- Green tea also has an anti-androgen effect. EGCG inhibits the enzyme that coverts testosterone into DHT, a potent androgen and key player in acne severity.
- The anti cancer properties of EGCG have been widely studied for their ability to inhibit skin tumour growth.
Topical application of EGCG ~ How well does it penetrate the skin?
The topical use of polyphenols, depend on their ability to penetrate the skin. In general, polyphenols are hydrophilic (affinity for water) and hardly penetrate the epidermal barrier. However, penetration has been improved with the use of liposomes!
What are Liposomes and how do they work in skincare?
Liposomes are used as a ‘carrier’ to take the active ingredients across the skin layers, assist in penetration and deliver it to the site of action! They do this by encapsulating, protecting and delivering the ingredients to the right place in the skin and are then slowly released providing a long lasting effect.
Benefits of topical application
The topical administration of catechins can decrease UV induced changes in the epidermis and studies have shown that EGCG regulates melanin pigmentation and might be used as a whitening ingredient in cosmetics.
It also holds great promise for acne sufferers. A human clinical study shows that topical application of 1 and 5% EGCG significantly improves acne in 8 weeks.
So whats the best way to prepare green tea?
The traditional way of preparing teas is brewing leaves in hot water at a temperature of 70 – 100°C.
For the best extraction of antioxidant compounds from green tea it is recommended to employ low temperatures since over 90°C the potent anti-ageing polyphenols are destroyed!
It’s evident that consumption of green tea holds many great benefits in relation to skin health and can slow down the rate in which our skin ages. Now go put that kettle on!
- Dokhani, A. Amini, J. Gortzi, O. et al. (2017). ‘Enhanced Efficacy and Bioavailability of Skin-Care Ingredients Using Liposome and Nano-liposome Technology, Modern Applications of Bioequivalence & Bioavailability, (2).
- Grant, P. Ramasamy, S. (2012). ‘An Update on Plant Derived Anti-Androgens’, International Journal of Endocrinology and Metabolism, (2), pp. 497-502.
- Hong, YH. Jung, EY. Noh, DO. et al. (2014). ‘Physiological effects of formulation containing tannase-converted green tea extract on skin care: physical stability, collagenase, elastase, and tyrosinase activities’, Integrative Medicine Research, (3), pp. 25-33.
- Khan, N. Mukhtar, H. (2007). ‘Tea polyphenols for health promotion’, Life Sciences, (7), pp. 519-533.
- Kim, E. Hwang, K. Cho, JY. (2018). ‘Skin Protective Effect of Epigallocatechin Gallate’, International Journal of Molecular Sciences, (1), pp.173.
- Lantano, C. Rinaldi, M. Corradini, C. (2015). ‘Effects of alternative steeping methods on composition, antioxidant property and colour of green tea, black and oolong tea infusions’, Journal of Food Science and Technology, (12), pp. 8276-8283.
- Saric, S. Notay, M. Sivamani, RK. (2017). ‘Green Tea and Other Tea Polyphenols: Effects on Sebum Production and Acne Vulgaris’, Antioxidants, (1), pp.1
- Yoon, JY. Kwon, HH. Min, SU. et al. (2012). ‘Epigallocatechin-3-Gallate Improves Acne in Humans by Modulating Intracellular Molecular Targets and Inhibiting P.acnes’, Journal of Investigative Dermatology, (2), pp.429-440.