Scientists Discover How Stress Can Cause Gray Hair
2020-01-27
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1A new study provides scientific evidence to support the idea that stress can cause a person's hair to turn gray.
2A team from America's Harvard University said the new study is the first to show a clear link between stress and graying hair.
3The findings were recently published in the journal Nature.
4Researchers say they discovered a chemical process that can change hair color during times of stress.
5The process is linked to the body's "fight-or-flight" reaction that can happen during dangerous situations.
6Ya-Chieh Hsu is a professor of Stem Cell and Regenerative Biology at Harvard.
7She said in a statement that the research team was in search of the first scientific confirmation of the commonly held belief that stress can cause gray hair.
8"Everyone has an anecdote to share about how stress affects their body, particularly in their skin and hair - the only tissues we can see from the outside," Hsu said.
9The team used experiments with mice to look at how stress affects stem cells in hair follicles.
10Most people have about 100,000 hair follicles on their head.
11The follicles are responsible for making melanocytes, the cells that give hair its color.
12As people age, melanocyte production is reduced.
13This causes a person's hair to begin turning gray naturally.
14At first, the researchers suspected that an immune attack caused by a stressful event might be targeting the melanocyte stem cells.
15That theory, however, turned out to be false.
16The mice lacking immune cells still showed signs of graying hair.
17The team also thought the hormone cortisol, which always increases in the body during times of stress, might be a likely cause.
18However, when researchers removed the gland that produces the cortisol hormones, the hair of mice still turned gray.
19The scientists then centered their experiments on the body's sympathetic nervous system.
20This is the body system that controls "fight-or-flight" reactions in dangerous situations.
21The sympathetic nervous system is made up of a collection of nerves that extend through the body, including the skin.
22When the mice were subjected to short-term pain or placed in stressful laboratory conditions, these nerves released a chemical called norepinephrine.
23The chemical then flowed through the stem cells up into the hair follicles -- where melanocytes are kept.
24The researchers found that when the norepinephrine was released, all the melanocyte stem cells were highly activated and changed into pigment-producing cells.
25This overproduction process resulted in the early loss of color-producing cells.
26Ya-Chieh Hsu said the experiments confirmed the team's belief that stress is bad for the body.
27She added that the results demonstrated the harmful effects are more major than what the researchers had imagined.
28"After just a few days, all of the pigment-regenerating stem cells were lost. Once they're gone, you can't regenerate pigments anymore. The damage is permanent," Hsu said.
29The scientists said their research could lead to new treatments for stress-related graying in the future.
30Graying hair is just one example of how stress affects the body.
31New experiments could also be carried out in other areas, as well, the team said.
32These could include studies to see whether stress can also cause changes in body tissues.
33Hsu said she would also like to study whether stress has a large effect on the overall aging process.
34"We don't know if that is true yet. We are interested in finding out the link," she said.
35I'm Bryan Lynn.
1A new study provides scientific evidence to support the idea that stress can cause a person's hair to turn gray. 2A team from America's Harvard University said the new study is the first to show a clear link between stress and graying hair. The findings were recently published in the journal Nature. 3Researchers say they discovered a chemical process that can change hair color during times of stress. The process is linked to the body's "fight-or-flight" reaction that can happen during dangerous situations. 4Ya-Chieh Hsu is a professor of Stem Cell and Regenerative Biology at Harvard. She said in a statement that the research team was in search of the first scientific confirmation of the commonly held belief that stress can cause gray hair. "Everyone has an anecdote to share about how stress affects their body, particularly in their skin and hair - the only tissues we can see from the outside," Hsu said. 5The team used experiments with mice to look at how stress affects stem cells in hair follicles. Most people have about 100,000 hair follicles on their head. The follicles are responsible for making melanocytes, the cells that give hair its color. As people age, melanocyte production is reduced. This causes a person's hair to begin turning gray naturally. 6At first, the researchers suspected that an immune attack caused by a stressful event might be targeting the melanocyte stem cells. That theory, however, turned out to be false. The mice lacking immune cells still showed signs of graying hair. 7The team also thought the hormone cortisol, which always increases in the body during times of stress, might be a likely cause. However, when researchers removed the gland that produces the cortisol hormones, the hair of mice still turned gray. 8The scientists then centered their experiments on the body's sympathetic nervous system. This is the body system that controls "fight-or-flight" reactions in dangerous situations. 9The sympathetic nervous system is made up of a collection of nerves that extend through the body, including the skin. When the mice were subjected to short-term pain or placed in stressful laboratory conditions, these nerves released a chemical called norepinephrine. The chemical then flowed through the stem cells up into the hair follicles -- where melanocytes are kept. 10The researchers found that when the norepinephrine was released, all the melanocyte stem cells were highly activated and changed into pigment-producing cells. This overproduction process resulted in the early loss of color-producing cells. 11Ya-Chieh Hsu said the experiments confirmed the team's belief that stress is bad for the body. She added that the results demonstrated the harmful effects are more major than what the researchers had imagined. "After just a few days, all of the pigment-regenerating stem cells were lost. Once they're gone, you can't regenerate pigments anymore. The damage is permanent," Hsu said. 12The scientists said their research could lead to new treatments for stress-related graying in the future. Graying hair is just one example of how stress affects the body. New experiments could also be carried out in other areas, as well, the team said. These could include studies to see whether stress can also cause changes in body tissues. 13Hsu said she would also like to study whether stress has a large effect on the overall aging process. "We don't know if that is true yet. We are interested in finding out the link," she said. 14I'm Bryan Lynn. 15Bryan Lynn wrote this story for VOA Learning English. Ashley Thompson was the editor. 16We want to hear from you. Write to us in the Comments section, and visit our Facebook page. 17________________________________________________________________ 18Words in This Story 19stress - n. feelings or worry or nervousness caused by difficult situations or problems 20anecdote - n. a short story that you tell someone about something that happened to you or someone else 21follicle - n. any of the very small holes in the skin that a hair grows from 22immune - adj. relating to the way the body fights disease 23hormone - n. one of several chemicals produced in the body that influence growth and development 24gland - n. an organ of the body that produces chemicals 25pigment - n. a substance that gives something color 26regenerate - v. to grow again or make something grow again