Collagen and green tea in relation to skin protection

Collagen and green tea are often promoted in the media as ‘healthy’ and ‘cure-alls’, So, how important are they for a healthy skin?

Collagen is a long fibrous structural protein constituting roughly 70 – 80% of the dry weight of our skin.  It forms fibrous bundles with great tensile strength – these are what provide strength and elasticity in tissues found in the body including ligaments, tendons, cartilage and skin.  As we age, not only do levels of collagen fall, but also the distribution of collagen fibers alters; instead of a smooth even distribution of collagen fibrils they become increasingly distributed in large, bundle-like aggregates, sparsely arranged through the dermis [5].  The dermis provides the strength and structure of the skin.

Matsuda et al showed in 2006 that ingestion of hydrolyzed collagen (collagen broken down in to smaller, much more easily digested pieces- also called collagen peptides-, giving up to 95% bioavailability with no toxic effects [12]) enhances the formation of collagen fibrils in the dermis.  This study also showed an increase in the number of fibroblasts – these are the cells that make collagen and are themselves important in skin structure. [7,13].

There is support for these findings. A well known British product containing hydrolyzed collagen was consumed by 22 participants in a clinical study to gauge it’s effects on wrinkle formation and hydration in the skin over a period of 12 weeks (14). Participants ingesting hydrolyzed collagen found a reduction of 26% in fine wrinkle formation.  A protective effect was also seen against the formation of deep-wrinkles, with a reduction of 24% compared to control participants receiving a placebo.  Volunteers also reported improvements in skin tone and suppleness of 32% and 45% respectively.

Ingestion of hydrolyzed collagen also increases skin hydration as reported by, among others, Morganti [9,10] and supported by Sumida [14]. Consumption of hydrolyzed collagen seems to increase the water-binding capacity of the epidermis, so the surface layers of the skin can retain more moisture – 68% of volunteers reported that their skin was less dry after 8 weeks of taking hydrolyzed collagen.  Keeping the skin functioning as best as possible is a great protective strategy, as well as something that will keep us feeling good.  Based upon these studies regular ingestion of collagen may help maintain normal functioning and slow ageing

Green tea has been regarded as a health-giving medicinal drink for centuries.  Matcha green tea is a fine bright green powder made from the finest, shade-grown tender green tea buds, and it is this form of green tea that yields the greatest benefits.

Green tea contains very high levels of polyphenols. Polyphenols have been studied in animals and human model systems. In such studies polyphenols have an antioxidant effect for your whole body, and also protect the skin from sun damage.  Although sunlight does stimulate skin vitamin D synthesis, the UV component of sunlight  is very damaging.  Solar UV radiation is the cause of a large proportion of skin diseases, the most severe being skin cancer.  It is also considered to be one of the most preventable types of cancer [11,4,1].  UV radiation may damage your skin by causing DNA damages, reducing levels of antioxidant enzymes, immunosuppression, oxidative stress by creating free radicals, inflammation, initiating tumours, promoting tumour growth, and premature ageing of the skin. Both UVA light and UVB light cause damage, penetrating to different depths of the skin and so damaging different layers [11,2,3].

Polyphenols found in matcha green tea seems to offer one practical way to help protect yourself against the raft of damaging effects sunlight can have.  Such benefits have also been seen in human skin, where inflammation and oxidative stress induced by UV radiation is inhibited by green tea [6].  Green tea extracts protect human skin fibroblasts from premature cell death caused by reactive oxygen species [15].  Drinking green tea also protects human cellular DNA from UV and visible radiation-induced DNA damage [9].

More studies are clearly wanted to prove the indicated health benefits of both collagen and green tea extracts. This will show their potential power to contribute to help build a healthy lifestyle.

References:

1. Afaq F, Mukhtar H. (2006) Botanical antioxidants in the prevention of photocarcinogenesis and photoaging. Exp Dermatol. 15:678–84.

2. Afaq F. Natural agents: (2010) Cellular and molecular mechanisms of photoprotection. Arch Biochem Biophys. 2010 Dec 11.

3. Bachelor MA, Bowden GT. (2004) UVA-mediated activation of signaling pathways involved in skin tumor promotion and progression. Semin Cancer Biol. 14:131–8.

4. Bowden GT. (2004) Prevention of non-melanoma skin cancer by targeting ultraviolet-B-light signalling. Nat Rev Cancer. 4:23–35

5. Cosgrove MC et al, (2007) Dietary nutrient intakes and skin ageing appearance among middle aged American women. Am. J. Clin. Nutr. 86: 1225-1231

6. Katiyar SK, Afaq F, Perez A, Mukhtar H. (2001) Green tea polyphenol (−)-epigallocatechin-3-gallate treatment of human skin inhibits ultraviolet radiation-induced oxidative stress. Carcinogenesis.  22:287–94

7. Matsuda et al, (2006) Effects of ingestion of collagen peptide on collagen fibrils and glycosaminoglycans in the dermis. J Nutri Sci Vitaminol 52: 211-215

8. Morganti P, Randazzo SD, (1987) Enriched gelatine as skin hydration enhancer. L Appl. Cosmtol., 5: 105-120

9. Morley N, et al. (2005) The green tea polyphenol (−)- epigallocatechin gallate and green tea can protect human cellular DNA from ultraviolet and visible radiation-induced damage. Photodermatol Photoimmunol Photomed. 21:15–22.

10. Morganti P, Randazzo SD, Bruno C, (1988) Oral treatment of skin dryness. Cosmet Toilet 103: 77-80

11. Nichols JA, Katiyar SK. Skin photoprotection by natural polyphenols: anti-inflammatory, antioxidant and DNA repair mechanisms. Arch Dermatol Res. 2010; 302:71–83.

12. Final report on the safety assessment of hydrolyzed collagen. (1985) J. Am. Coll. Toxicol., 4: 199-221

13. Postlethwaite AE, Seyer JM, Kang AH, (1978) Chemotactic attraction of human fibroblasts to type I, II, and III collagens and collagen derived peptides. Proc. Natl. Acad. Sci. USA 75: 871-875

14. Sumida E, (2004) The effects of oral ingestion of collagen peptide on skin hydration and biochemical data of blood. J. Nutritional Food 7 (3): 45-52

15. Silverberg J. I. et al, (2011) Green tea extract protects human skin fibroblasts from reactive oxygen species induced necrosis. Journal of Drugs in Dermatology, vol. 10, no. 10, pp. 1096–1101, 2011.

16. Singh T., Katiyar S. K., (2011) Green tea catechins reduce invasive potential of human melanoma cells by targeting COX- 2, PGE2 receptors and epithelial-to-mesenchymal transition,” PLoS ONE, vol. 6, no. 10, Article ID e25224, 2011.

17. Zague V et al, (2011) Collagen Hydrolysate Intake Increases Skin Collagen Expression and Suppresses Matrix Metalloproteinase 2 Activity.  J. Med. Food 14: 618-624