By Erin Matheson '18
Gray hair historically symbolizes the aging process. Even with the spectrum of hair colors, both natural and artificial, humans all share one common characteristic: we all gray. Eventually, everyone despite his, her or their hair color will eventually hit a point in their life when their hair fades to gray. This idea of graying has been referred to as the 50/50/50 rule of thumb: at age 50, 50% of the population will be 50% gray. It is well known that grayness is significantly linked to one’s genetic code or DNA, so if either your mother or father went gray, you most likely will too. It has not been until just recently that scientists have identified the exact gene loci responsible for hair grayness.
An article recently published in Newsweek summarized the Londonstudy that found the gene directly linked to graying. In the study, researchers analyzed the DNA of 6,000 Latin American people to locate genes that determine different attributes of hair. Kaustabh Adhikari, the lead author of the study, said that a known gene, IFR, responsible for the light hair pigmentation of individuals of European descent, is now linked to graying. The process of graying begins in the follicles of the scalp. At the bottom of every follicle is an area where cells work in conjunction to create and assemble hair. The keratinocyte proteins construct hair and melanocyte proteins create its pigmentation. Hair that has lost the majority of its melanin is gray; hair that has lost all of the pigment is white. The IFRgene regulates the process of melanin release.
Past research before the IFR4 discovery, identified melanin deficiency as the root cause of graying, but it lacked the direct mechanism responsible. In a previous study, melanocyte-tagged transgenic mice and aging human hair follicles were used to demonstrate that hair graying is caused by defective maintenance of melanocyte stem cells. This overarching idea that melanin is responsible for hair color has been known for quite some time; however, as it is evident from this study the direct loci responsible still remained unknown. At the time, researchers only knew physiologic aging of melanocyte stems cells caused hair graying through a loss in differentiated melanocytes in the hair matrix. Now, information pertaining to hair graying is known down to the gene loci.
In addition to genetics being a main contributor to graying, it is common knowledge that stress is also a root cause. As a college student who experiences a lot of daily stress, I researched if I will become gray in the near future. Although the onset and progression of hair graying is closely related to chronological age and genetics, stress can hasten depigmentation for individuals that are already genetically predisposed for gray hair. However, there is no scientific evidence demonstrating a direct relationship between stress and graying. So, as the third round of midterms approach, try to relax and blame your early onset of gray on your genes.