What Causes Grey HairEach individual hair follicle has pigment producing cells called melanocytes. As the hair strand is being formed, the melanocytes cells inject pigment (melanin) into cells containing keratin, the protein structures that makes up our hair follicles, skin, and nails.
Throughout our lifetime, our melanocyctes continue to inject pigment into our hair's keratin, giving it color, however, after a certain amount of years of producing, our melanocyctes go on strike so to speak and stop making as much melanin which causes grey hair, or make no melanin at all which causes white hair.
When you ask a scientist why this happens, the common answer given us is usually "genetics", that our genes regulate the predestined exhaustion of the pigmentation potential of each individual hair follicle. However, there is a more indepth explanation about what happens when our hair turns grey or white, and understanding the science behind that is leading to innovations that will change the inevitability of having to put up with a loss of hair color.
Stem Cell Research - Reversing Grey HairIn 2005, Harvard scientists were the first to propose that a failure of melanocyte stem cells to maintain the production of melanocytes caused the graying of hair. They were correct, and other scientist have expanded on their research.
The simplified definition of a stem cell, is a cell whose job is to make more cells. Stem cells repair and build our bodies. As explained above in this article, two different types of cell production occurs when our bodies produce a non-grey strand of hair. The melanocytes stem cells produce the hair color, and other stem cells produce the hair follicle.
Scientists have researched this coordinated production between the two different stem cell types, and have discovered a signalling protein called "Wnt". Think of Wnt as a type of work foreman that oversees the production of hair and tells each different stem cell type how fast to work. Wnt has everything to do with why our hair turns grey. When our melanocytes stem cells do not have enough Wnt protein, they do not get the signal to produce hair color.
Professor Mayumi and a team of researchers at the New York University Medical Center have successfully restored hair color in mice by manipulating the Wnt signalling proteins. Mayumi is confidant that the research will lead to solutions of melanocyte related issues both serious and cosmetic in humans, including skin diseases such as melanoma, and of course grey hair.
Researchers at the Tokyo University of Science, have also experimented with stem cells in attempts to regrow hair and restore color. The researchers injected a bald and otherwise colorless mouse with stem cells from live hair follicles, and were able to grow dark tufts of hair on the injection site. The research is intended to lead to solutions for both baldness and grey hair in humans.
L'Oreal Research - Preventing Grey HairDoctor Bruno Bernard is the head of hair biology at L'Oreal in Paris. L'Oreal, a company known for hair and beauty products, is currently supporting research into innovative methods of preventing hair from turning grey.
Bernard and his team have been studying the melanocyte stem cells found in our skin that are responsible for making skin the pigment that it is. The researchers wanted to know why our skin doesn't turn grey with age but our hair does. They discovered an enzyme called TRP-2 that is present in our skin stem cells, but is missing in our hair follicle stem cells. They observed that TRP-2 helped protect the melanocyte stem cells in skin from damage, and so helped those stem cells to last longer and function better. The TRP-2 enzyme provided an advantage to our skin cells that the cells involved with hair production do not have.
L'Oreal intends to innovate a topical treatment, such as a shampoo for hair, that will replicate the effect of the TRP-2 enzyme and give the melanocyte stem cells in hair follicles the same advantage that skin stem cells have, thereby preventing and delaying grey hair from happening in the first place.