But can stress turn our hair gray? There's probably no job more stressful than president of the United States. And U.S. presidents — from Bill Clinton to Barack Obama — have been subjected to before-and-after comparisons showing how the world's most stressful job can take its toll on hair.
Even Marie Antoinette supposedly showed up for her date with the guillotine with gray hair. Onlookers believed that her hair color changed overnight as she stressed about her fate. Though in her case, the sudden graying was likely because she wasn't wearing a wig, which was common in 18th-century France.
And those presidents? Well, Clinton had salt-and-pepper hair when he entered the office at age 46; it was pretty much white when he left at age 54. Bush had a solid head of gray after his eight years in office too [source: Willingham]. And Obama entered his eight years with dark black hair. After his term ended that black hair was totally salt-and-pepper.
But in most people, stress isn't the cause of graying. Our hair starts to turn gray naturally between the ages of 30 and 35, and things like genetics play a role when it starts. But why does our hair go gray at all?
Why Hair Goes Gray
Your head contains hundreds of thousands of follicles, and each follicle is charged with producing one hair. Before hair emerges, other cells known as melanocytes determine the hair's pigment. Once a hair's color is set, it's set.
When our hair turns gray, it's because of reduced amounts of melanin, and when hair is completely white, it's because it lacks melanin altogether. That's partly because of we lose the amount of stem cells that can become melanin-producing cells. But why?
Scientists aren't exactly sure. It could be those stem cells wear out or they become damaged. The support systems that help keep them working could also fail. But our hair follicles also simply produce less color as we/they age. So it makes sense that as each strand of hair dies and falls out and new strands regenerate in their place, their color will be lighter over time.
Genetics and Graying
But when — and if — you go gray is mostly influenced by your parents, as our genetics seem to have the most control over what comes out of each hair follicle. Scientists have been trying for decades to determine what's happening with our genes and cells when hair goes gray. Not only because they want to solve the mysteries of gray hair, but also because our hair might reveal information that's useful in treating other conditions related to aging.
In 2004, for example, researchers from the Dana-Farber Cancer Institute in Boston were studying melanoma, which involves an overproduction of melanocytes in the skin that can lead to skin cancer. While trying to learn more about the nature of melanocytes, the researchers found that hair might go gray as the supply of melanocyte stem cells is depleted. Even before those stem cells are completely gone, though, they begin to make errors, such as depositing the pigment at the wrong place in the follicle so they have no effect on the hair [source: Dana-Farber Cancer Institute].
The results of a 2009 Japanese study published in the journal Cell indicated that stress can in fact cause gray hair, but not the type of stress that comes with a teenage driver or an impending job interview. Rather, researchers found that genotoxic stress, in the form of ultraviolet light and chemicals, damages our DNA and could cause the depletion of those melanocyte stem cells.
Though research seems to indicate that we could stop the DNA damage by removing the genotoxic stress, the researchers estimate that just one mammalian cell is subjected to 100,000 such stressors in one day, making complete avoidance impossible.
Remove the Stress, Reverse the Gray?
But a small 2021 study from researchers at Columbia University Vagelos College of Physicians and Surgeons is the first with measurable evidence that links everyday stress to gray hair — and says it's even reversible. The researchers analyzed individual hairs from 14 volunteers. They compared the results with the volunteer's "stress diary," in which they tracked and rated their weekly level of stress. The researchers were surprised to discover that hair color was restored in some participants when stressors were eliminated.
"Understanding the mechanisms that allow 'old' gray hairs to return to their 'young' pigmented states could yield new clues about the malleability of human aging in general and how it is influenced by stress," study senior author Martin Picard, Ph.D., said in a press statement. Picard is an associate professor of behavioral medicine at Columbia University. "Our data add to a growing body of evidence demonstrating that human aging is not a linear, fixed biological process but may, at least in part, be halted or even temporarily reversed."
Take that, gray hair!
Different Hair Colors
Though hair comes in a variety of hues, there are only two types of melanin, or pigment. Eumalin is a dark brown or black pigment, while pheolmalin is reddish yellow. When the two combine in varying levels, as dictated by genetics, they produce the wide range of hair colors we all sport.
American Academy of Dermatology. "Feeling Stressed? How Your Skin, Hair and Nails Can Show It." ScienceDaily. Nov. 12, 2007. (July 6, 2009) http://www.sciencedaily.com /releases/2007/11/071109194053.htm
American Psychological Association. "Stress effects on the body." Nov. 1, 2018. (March 16, 2022) https://www.apa.org/topics/stress/body
Basler, Barbara. "Myth Buster: Can Stress Cause Gray Hair?" AARP Bulletin Today. Jan. 15, 2009. (July 6, 2009) http://bulletin.aarp.org/opinions/othervoices/articles/myth_buster_can_stress_cause_gray_hair_.html
Bergeron, Kat. "What makes hair go gray?: Hint: It has something to do with age." Sun Herald. Feb. 28, 2008.
Carey, Benedict. "Too Much Stress May Give Genes Gray Hair." The New York Times. Nov. 30, 2004. (July 6, 2009) http://www.nytimes.com/2004/11/30/health/30age.html
Cell Press. "Stress Makes Your Hair Go Gray." ScienceDaily. June 15, 2009. (July 6, 2009) http://www.sciencedaily.com /releases/2009/06/090611120734.htm
Cooney, Elizabeth. "Why stress grays hair." Boston Globe. June 15, 2009. (July 6, 2009) http://www.boston.com/news/health/articles/2009/06/15/why_stress_grays_hair/
Cooper, Helene. "For Young President, Flecks of Gray." New York Times. March 5, 2009. (July 6, 2009) http://www.nytimes.com/2009/03/05/us/politics/05gray.html
Dana-Farber Cancer Institute. "Scientists Discover the Cellular Roots of Graying Hair." ScienceDaily. Jan. 12, 2005. (July 6, 2009) http://www.sciencedaily.com /releases/2005/01/050111174107.htm
Dell'Amore, Christine. "Gray Hair Caused by Stress (Cell Stress, That Is)" National Geographic News. June 16, 2009. (July 6, 2009) http://news.nationalgeographic.com/news/2009/06/090616-stress-gray-hair.html
Hall-Flavin, Daniel K. "Stress and hair loss: Are they related?" Mayo Clinic. Oct. 4, 2008. (July 6, 2009) http://mayoclinic.com/health/stress-and-hair-loss/AN01442
Library of Congress. "Why does hair turn gray?" Feb. 12, 2009. (July 6, 2009) http://www.loc.gov/rr/scitech/mysteries/grayhair.html
Nishimura, Emi K. "Genotoxic Stress Abrogates Renewal of Melanocyte Stem Cells by Triggering Their Differentiation." Cell. June 12, 2009. (March 16, 2022) https://www.cell.com/cell/fulltext/S0092-8674(09)00374-2
Meyer, Laurence. "Why does hair turn gray?" Scientific American. March 26, 2001. (July 6, 2009) http://www.scientificamerican.com/article.cfm?id=why-does-hair-turn-gray
Parker-Pope, Tara. "Unlocking the Secrets of Gray Hair." New York Times. March 10, 2009. (July 6, 2009) http://www.nytimes.com/2009/03/10/health/10well.html
Picard, Martin. "Quantitative mapping of human hair greying and reversal in relation to life stress." Cell Biology. June 22, 2021. (March 16, 2022) https://elifesciences.org/articles/67437
Sanders, Robert. "Researchers find out why some stress is good for you." Berkeley News. April 16, 2013. (March 16, 2022) https://news.berkeley.edu/2013/04/16/researchers-find-out-why-some-stress-is-good-for-you/
Shmerling, Robert H. "Why does hair turn gray?" Harvard Health Blog. June 22, 2020. (March 16, 2022). https://www.health.harvard.edu/blog/hair-turn-gray-2017091812226
Tobin, D J. "Graying: gerontobiology of the hair follicle pigmentary unit." Experimental Gerontology. January 2001. (March 16, 2022) https://www.sciencedirect.com/science/article/abs/pii/S0531556500002102?via%3Dihub
Willingham, Val. "Shades of gray: What happens to presidents' hair?" CNN.com. Jan. 22, 2013. (March 16, 2022) https://www.cnn.com/2013/01/22/health/presidents-gray/index.html
Please copy/paste the following text to properly cite this HowStuffWorks.com article: