Gray hair can return to its original color and stress is undoubtedly involved. The universal marker of aging is not always a one-sided process. Few of the precursors of aging are more evident in the face of gray hair. Black, brown, gold, or red varieties tend to lose their youthful color as we age. While this may seem like a permanent change, new research suggests that the aging process can be undone, at least temporarily.
Gray hair can return
Evidence that gray hair may spontaneously color have existed as separate case studies within the scientific literature for decades. In a 1972 article, the late dermatologist Stanley Komaish reported an encounter with a 38-year-old man, which he described as “the most unusual feature.” Although most of the individual’s hair was either completely black or completely white, three strands were lighter near the tips but darker near the roots. This indicated a reversal of the normal aging process, which begins at the root.
In a study published today in eLife, a group of researchers provides the strongest evidence for this phenomenon to date in the hair of nearly a dozen people of different ages, races, and genders. It also aligns with reversal patterns of aging and periods of stress, which means that this aging-related process is closely related to our psychological well-being.
“These findings suggest that there is a window of opportunity during which graying is likely to be highly reversible,” says study co-author Ralph Pause, a dermatologist at the University of Miami. About four years ago Martin Picard, a mitochondrial psychologist at Columbia University, was considering how our cells grow in various steps, in which some of them begin to show signs of aging much earlier than others.
He realized that this mosaic process was clearly visible on our scalp, where our hair does not turn gray at the same time. “It seemed like hair, in a way, we know happens at the cellular level,” says Picard. “Perhaps there is something to learn. Perhaps the hairs that turn white first are more vulnerable or at least resistant.”
In discussing these ideas with his partner, Picard noticed something in the passage: if one could find a hair that was only partially gray and then calculate how fast the hair was growing, it would be possible to pinpoint the period when the hair begins . aging and thus asking questions about what happened in the individual’s life to trigger this change.
“I was thinking of this almost as an imaginary idea,” recalls Picard. Unexpectedly, however, his partner turned to him and told him that she had seen those two-colored hairs on his head. “She went to the bathroom and actually robbed a couple; that’s when she started this project,” he says.
Picard and his team began searching for other people with dual-colored hair through local ads, on social media, and verbally. Eventually, they were able to find 14 people, nine men and women between the ages of 65 and 18, with diverse ethnic origins (although most were white). Those individuals provided one- and two-color hairs from different parts of the body, including the scalp, face, and pubic region.
The researchers then developed a technique to digitize and measure subtle color changes, which they called the hair’s pigmentation pattern, along each strand. These patterns showed something surprising: In 10 of these participants, who were between the ages of nine and 39, some gray hair returned. The team also found that it occurs not only in the head but also in other areas of the body.
“When we saw this in pubic hair, we thought, ‘Okay, this is real,'” says Picard. “It doesn’t just happen in a person or in the head, but in the whole body.” He adds that because reversibility is only visible in certain hair follicles, however, it is likely limited to specific periods when changes can still occur.
Most people begin to notice their first gray hair in their 30s, although some may have them in their late 20s. According to Pause, this period, when aging has just begun, is probably the most reversible of the process. In people with a full head of gray hair, most strands have probably reached a “point of no return,” but there is a chance that some hair follicles are still too malleable to replace, she says.
“Most notably, they were able to show that, at the level of individual hair, bleaching is really reversible,” says Matt Caberlin, a biogerontologist at the University of Washington, who was one of the editors of the new study. he role, but did not participate in the work. “What we are learning is that the biological changes that occur with age are, in many cases, reversible, not only in hair but in different types of tissue – this is a good example of this.”
Gray hair can return
The team also examined the association between graying of hair and psychological stress because previous research had indicated that such factors can accelerate the aging process of hair. Anecdotes of such a relationship also appear throughout history: according to legend, the hair of the 18th century Queen Marie Antoinette of France turned white overnight just before her execution by the guillotine.
In a small subset of participants, the researchers identified segments in individual hairs where pigmentation patterns produced color changes. They then calculated the time the change occurred using the known average growth rate of a human hair – about one centimeter per month. These participants also provided a history of the most stressful events they had experienced over the course of a year.
This analysis showed that the time of aging or reversal corresponded to periods of significant stress or relaxation. In one person, a 35-year-old man with blonde hair, five strands of hair reversed the gray during the same time period, which coincided with a two-week break. Another subject, a 30-year-old woman with dark hair, had a lock consisting of a white section corresponding to two months during which she went through marital separation and relocation, her most stressful period of the year.
A psychoneuroimmunologist at the Giesen and Marburg University Hospital in Germany, who was not involved in this work, says that this is a “very constructive and well-conceptualized study.” But, he adds, because the number of cases the researchers were able to observe was relatively small, particularly in the stress-related part of the study, more research is needed to confirm these findings.
For now, the next step is to take a closer look at the link between stress and gray hair. Picard, Posse and their colleagues are awarding a grant to conduct another study that will potentially examine hair changes and stress levels – that is, asking participants to recall life events from the past, rather than follow up. for a specific period.
Ultimately, Picard says, hair can be seen as a powerful tool for assessing the effects of past life events on aging, because, like tree rings, hair is a kind of physical representation of extinction events. “It’s pretty clear that hair is part of your biological history in some way,” she says. “The hair grows outside the body and then crystallizes into this rigid and stable [structure] that contains the memory of its past.”