The Science Behind Coffee and Hair: How Caffeine Affects Hair Follicles?
Caffeine is not just for your morning coffee, it’s also making waves in the world of hair care. Shampoos are now available which contain caffeine, but does this really make a difference to how well your hair grows? The hair follicle lies underneath the skin's surface and cannot be seen. Hair growth begins at the root of the hair follicle.
The hair growth cycle consists of 3 continuous phases - this is where hair will grow, have a resting stage and then start to shed. Caffeine can positively affect the hair follicle by increasing the blood flow and energy production, which then extends the hair’s growth phase. Caffeine also works by acting as a phosphodiesterase inhibitor, which plays a role in promoting hair growth.
Some research also suggests that caffeine can block DHT (dihydrotestosterone), which is a hormone that is linked to hair loss. Caffeine has been demonstrated to increase the expression of insulin-growth factor 1 (IGF-1) in hair follicles. IGF-1 has been shown to be a factor in initiating and sustaining the growth phase in the hair cycle and so promotes hair growth and reduces hair loss.
Drinking Coffee vs. Applying Coffee: Which Method May Benefit Hair Growth?
It is unlikely that drinking coffee will stimulate the hair follicles, as the caffeine will not reach the hair roots in sufficient amounts. Drinking large amounts of caffeine can, however, negatively impact hair growth by causing dehydration, poor sleep and increased stress. Various hair products are now available which contain caffeine as the main ingredient to help with hair growth. Many of these products claim to nourish thinning hair and promote natural hair growth. Coffee masks are also a popular option at the moment. Although, you do need to be a little more careful with these as they may cause scalp irritation, hair dryness and potential staining or darkening of the hair if you have a lighter hair colour.
What the Research Shows: Evidence for Coffee's Role in Combating Hair Loss
In a study where patients were using caffeine in the management of their androgenetic alopecia, results show that the caffeine counteracted the suppressive effects of testosterone on hair growth. There was also a higher hair shaft elongation 120 hours after caffeine had been applied. The study clearly demonstrated that caffeine is a stimulator of human hair growth. To conclude, when done regularly, applying caffeine to the scalp does have benefits. It can help promote hair growth and lengthen the hair growth cycle. Drinking caffeinated drinks has no contribution to hair growth and should be consumed moderately and limited to 4 to 5 cups of tea or coffee.
