Now the researchers found how stress causes gray hair, When Maria Antoinette was captured during the French Revolution, her hair was said to have turned white overnight.
Anecdotes have long combined stress experiences with the phenomenon of graying hair. For the first time, scientists have discovered exactly how the process works: stress activates nerves that are part of the fight or flight response, which in turn causes permanent damage to regenerating pigment stem cells in hair follicles and now the researchers found how stress causes gray hair.
“Everyone has an anecdote to tell about how stress affects their body, especially skin and hair – the only tissue we can see from the outside,” the researchers said.
We want to find out whether this relationship is true and how stress causes changes in different tissues. Hair pigmentation is an affordable and understandable system so we have to start it, and we are also very excited to see if stress really causes gray hair. Because stress affects the entire body, researchers must first limit which body systems are responsible for connecting stress and hair color.
Initially the team suggested that stress triggers an immune attack on pigment producing cells. However, if mice without immune cells still show brown hair, the researchers turn to the hormone cortisol. But it’s a dead end again.
Stress always increases the level of the hormone cortisol in the body, so we think cortisol can play a role, the researchers say.
But surprisingly, when we removed the adrenal glands from mice, their hair was still bluish so they could not produce hormones like cortisol. After systematically shutting down various options, the researchers attacked the sympathetic nervous system, which is responsible for the body’s reaction to battle or flight.
Sympathetic nerves branch into each hair follicle in the skin. Researchers have found that stress causes these nerves to secrete the chemical norepinephrine, which is absorbed by nearby regenerating pigment stem cells. In hair follicles, certain stem cells act as reserves of pigment-producing cells.
When hair is regenerated, some stem cells turn into pigment-producing cells that color the hair.
The researchers found that norepinephrine from the sympathetic nerve caused excessive stem cell activation. All stem cells are converted to pigment-producing cells, where the reservoir runs out prematurely. When we began to study this, I hoped that stress had a negative effect on the body, but the harmful effects of the stress we found exceeded what I had imagined, researchers said.
After only a few days, all the pigment regeneration stem cells disappear. Once lost, you can no longer remake pigments. The damage is permanent. This finding underscores the negative side effects of protective evolutionary reactions, according to the researchers.
Acute stress, especially the fight or flight response, has traditionally been considered vital for animal survival. In this case, acute stress causes permanent fatigue in the stem cells.
To link stress with graying hair, researchers began with reactions throughout the body and more body-to-body interactions, cell-to-cell interactions and finally molecular dynamics.
This process requires a variety of research tools, including methods for manipulating organs, nerves, and cell receptors. To move from the highest level to the smallest details, we work with many scientists in various disciplines, using a combination of various approaches to solve very basic biological questions.
We know that peripheral neurons regulate the functions of organs, blood vessels and immunity, but little is known about how they regulate stem cells, the researchers said. With this research, we now know that neurons can control stem cells and their functions, and we can explain how they interact at the cellular and molecular level to connect stress with graying hair.
The results can help illuminate the effects of wider stress on various organs and tissues. This understanding will pave the way for new research that tries to modify or block the harmful effects of stress. By understanding how stress affects pigment regeneration stem cells, we have laid the foundation for understanding how stress affects other tissues and organs in the body.
Understanding how our tissues change under pressure is the first important step towards possible treatments that can stop or reverse the harmful effects of stress. There is still much to be learned in this field.