Rub this on your head and grow hair? (Photo by AMagill)
We've all heard about how Asians drink lots of green tea and usually have full heads of hair. Does this mean green tea improves hair growth?
Despite all the positive news about the health benefits of green tea, in my opinion the jury is still out on this one. Surprisingly, not a lot of studies have been done on green tea and hair growth in humans, especially when the green tea is topically applied.
In a recent study about green tea and human hair follicles, Kwon et al. report:
Green tea is a popular worldwide beverage, and its potential beneficial effects such as anti-cancer and anti-oxidant properties are believed to be mediated by epigallocatechin-3-gallate (EGCG), a major constituent of polyphenols.
Recently, it was reported that EGCG might be useful in the prevention or treatment of androgenetic alopecia by selectively inhibiting 5alpha-reductase activity. However, no report has been issued to date on the effect of EGCG on human hair growth. This study was undertaken to measure the effect of EGCG on hair growth in vitro and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro.
EGCG promoted hair growth in hair follicles ex vivo culture and the proliferation of cultured DPCs. The growth stimulation of DPCs by EGCG in vitro may be mediated through the upregulations of phosphorylated Erk and Akt and by an increase in the ratio of Bcl-2/Bax ratio. Similar results were also obtained in in vivo dermal papillae of human scalps. Thus, we suggest that EGCG stimulates human hair growth through these dual proliferative and anti-apoptotic effects on DPCs.
In this study, one of the main green tea catechins, epigallocatechin-3-gallate (or ECGC) was used topically in cultured hair follicles, cultured dermal papilla cells, and the scalps of human volunteers.
In cultured hair follicles, the application of a 95% green tea extract more than doubled the length of hair follicles. Hair growth almost tripled. In the cultured skin cells, the extract increased the growth of new cells in a dose-dependent manner.
The authors report that EGCG affects the expressions of Erk, Akt, Bcl-2 and Bax, and suggest that this effect may be the reason behind the results seen in follicle and skin cell cultures.
To see whether similar effects happen in vivo, the authors mixed 10% EGCG in ethanol and applied it directly onto human scalps. Again, significant changes in the expressions were seen, which means that if their theory about these expressions being the cause of hair growth, ECGC works both in vitro and in vivo. The authors conclude that ECGC stimulates hair growth through its proliferative and anti-apoptotic effects, and that ECGC may prolong the anagen stage.
So can you do the same thing at home? It seems so.
To make your own inhuman experiment, you'd need to buy a green tea extract with as much catechins as possible (95% ECGC was used in the study) and mix it with ethanol. All you need to do then is rub it on your head and wait for results.
If you decide to try it, let me know what happens.
For more information on green tea, see these posts:
Drinking 10 Cups of Green Tea Daily and Not Smoking Could Add 12 Years to Your Life
Black Tea is More Effective in Reducing Superoxide Dismutase than Green Tea
Green Tea Reduces the Formation of AGEs
Dental Health Effects of Green and Black Tea