Scientists say they now know why stress causes grey hair

Health Page d'accueil

April 23, 2024

Scientists have said they now understand how stress can cause grey hair, as a study specifically states that stress is a very strong factor in just how quickly our hair does turn grey.

According to experts, our hair colour may change because of the nerves activated in our “fight or flight” response system. But it is not all about stress, genetics playing a very important part in the process.


A new research from Harvard University also reveals the exact mechanisms behind this. According to that study, cortisol, which is our stress hormone, can provoke many health negative effects when it is heightened, and even more so in the long term.

But the real issue actually comes from a different part of the body’s fight or flight response, the sympathetic nervous system, which controls our bodies’ involuntary reactions to dangerous or stressful situations, and can be found all over our body, including hair follicles.

The chemicals that we produce during a stress response (mainly norepinephrine) are responsible for our stem cells producing pigments to activate ahead of time and to exhaust our hair’s supply in colours.

“The detrimental impact of stress that we discovered was beyond what I imagined,” Ya-Chieh Hsu, an associate professor of stem cell and regenerative biology at Harvard said. “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.”

Reasons why we go grey

Even if environmental factors such as stress play an important role, in most cases the main reason why people’s hair turn grey is simple genetics.

“Grey hair is caused by loss of melanocytes (pigment cells) in the hair follicle. This happens as we age and, unfortunately, there is no treatment that can restore these cells and the pigment they produce, melanin,” Dr. Lindsey A. Bordone, a dermatologist and professor of dermatology at Columbia University Medical Center, stated. “Genetic factors determine when you go grey. There is nothing that can be done medically to prevent this from happening when it is genetically predetermined to happen.”

But there are some risk factors according to a 2013 study, such as smoking. Deficiencies in protein, vitamin B-12, copper and iron can also have an influence on our hair turning grey, as well as oxidative stress, which is an imbalance of free radicals and antioxidants that can damage tissue, proteins, and DNA.

So if you are trying to look young for as long as possible and want to delay the greying, there are several changes that can be made in your lifestyle to help that. For instance, having a diet high in omega-3 fatty acids (that can be found in walnuts and fatty fishes), avoiding the ultraviolet light of the sun, and taking more vitamins B-12 and B-6.

Plenty left to learn

The Harvard research having only been tried on mice until now, it would be great to reiterate the study on humans, in order to get stronger and clearer conclusions. But the study goes beyond our hair turning grey, as it implies that other internal changes might happen due to prolonged stress.

“By understanding precisely how stress affects stem cells that regenerate pigment, we’ve laid the groundwork for understanding how stress affects other tissues and organs in the body,” said Hsu. “Understanding how our tissues change under stress is the first critical step towards eventual treatment that can halt or revert the detrimental impact of stress.” All of this means there is still hope for us to one day be able to stop and revert premature grey hair, and so plenty more for us to do and learn in the area!