A new study shows strong evidence that psychological stress is connected to the graying of hair but that the process is potentially reversible.
Hair color can be restored when stressors are eliminated, according to a team from Columbia University Irving Medical Center in New York City, who published their findings in the journal eLife last week.
Mr. Martin Picard, the study’s senior author said, “understanding the mechanisms that allow ‘old’ gray hairs to return to their ‘young’ pigmented states could yield new clues about the malleability of human aging in general and how it is influenced by stress could yield new clues about the malleability of human aging in general and how it is influenced by stress.”
The data add to a growing body of evidence demonstrating that human aging is not a linear, fixed biological process but may, at least in part, be halted or even temporarily reversed.
The majority of people notice their first gray hairs in their 30s or late 20s, according to the researchers, and this is when the process is most reversible. Those who are older and have a full head of grey hair will almost certainly be out of luck, regardless of how much psychological stress they eliminate in their lives. However, some hair follicles may be altered by reduced stress, according to scientists.
The study analyzed individual hairs from 14 volunteers and compared the results with entries in stress diaries participants kept for the experiments. Volunteers were asked to catalog and rate their levels of stress each week.
Researchers also looked at how the expression levels of hundreds of proteins in the hairs varied as the hair grew longer. They noticed that when hair color shifted in one direction or the other, roughly 300 proteins changed as well.
The researchers believe that grey hairs change is a stress-induced alteration in mitochondria, which act as tiny antennae inside the cell that respond to various signals including stress.
“Based on our mathematical modeling, we think hair needs to reach a threshold before it turns gray. In middle age, when the hair is near that threshold because of biological age and other factors, stress will push it over the threshold and it transitions to gray,” Mr. Picard explained.