Is it possible to recover from stress-related gray hair?

The famous story that Queen Marie Antoinette, who was captured in the French Revolution, went gray overnight is an anecdote representing the relationship between stress and gray hair. Since it is difficult to know the relationship between psychological stress and hair pigmentation experienced by individuals, the authenticity was not certain, of course.

However, a Columbia University research team asked 14 volunteers to keep a stress journal every day to rate their daily stress on a weekly basis. Accordingly, hair samples were taken and correlated with stress and the degree of pigmentation in the partial hair that had grown during that period. For reference, human hair grows about 1/20 of a millimeter per hour.

Even if you have gray hair, it is difficult to see it with the naked eye because the color change does not come out clearly and clearly in the hair part. However, the team explains that subtle color changes can be identified and measured using a high-resolution scanner.

It is said that a surprising discovery was made when the hair color change obtained in this way was compared with the stress log written by the participant. Not only was there a clear correlation between stress and gray hair, but it was also confirmed that the partial color that had temporarily grayed out when the stress was relieved returned to its original density. According to a survey of 5 people who had leisure time during vacation, there were people whose hair returned to black hair during vacation. It is said that there has not been a case of quantitative recording of gray hair returning to its original color so far.

In addition, as a result of measuring the amount of thousands of proteins according to the length of the hair, 300 types of proteins were changed as the gray hair changed. The team believes that this change occurred because stress caused mitochondrial changes. The research team reveals that mitochondria not only serve as a cellular power source, but actually respond to various signals, including psychological stress, like a small antenna.

A Columbia University study shows that the mechanism of gray hair in humans is reversible. However, this does not appear to apply to all mechanisms of graying. Mathematical models believe that hair will reach a threshold before it turns gray. And depending on the biological age and other factors, when the head reaches this limit, the stress exceeds the threshold, and the hair becomes gray. In other words, even if a person in their 70s, who has been gray for a long time, thoroughly reduces stress, their hair does not turn black, and it is difficult to think of cases in which the hair exceeds the threshold for gray hair even when a teenager is subjected to a certain amount of stress.

For reference, a study published in 2020 by a research team at Harvard University also showed that the stem cells producing hair follicle pigment did not work as a result of acute stress to the experimental mice. Related information can be found here.