Many people struggle with aging, as the sight of their once sprightly body drooping and sagging leaves deep psychological scars. Turning gray is often the first sign that the glory days of youth are coming to an end, although a new study in the preprint repository bioRxiv offers hope by indicating that the graying process isn’t necessarily permanent, and that white hairs can regain their original color when stress levels are low.
To conduct their research, the study authors collected hairs from 14 people of various ethnic backgrounds, and looked for samples that were colored at the tip but gray at the root – indicating that they are in the process of going gray. To their amazement, however, they also found numerous hairs that became less gray towards the root, suggesting that they were somehow regaining their previous color.
They then performed a proteomic analysis of their collected samples in order to ascertain the differing protein profiles of gray and colored hairs. Results showed that gray hairs contained a large number of upregulated mitochondrial proteins that are normally involved with energy metabolism.
Interestingly, many of these proteins are also known to become upregulated in response to stress, and have been associated with various other age-related features like DNA degradation. Crucially, though, many of these effects can be reversed by lifestyle changes, such as engaging in regular exercise or switching to a healthier diet.
Suspecting that stress levels may have played in role in the re-coloration of graying hairs, the researchers asked participants to describe their most and least stressful episodes of the past 12 months, providing precise dates for these events. Working on the basis that hair grows at a rate of about a centimeter (0.4 inches) per month, the study authors were then able to match up sections of each hair with particular life events.
Results showed that the reversal of graying always correlated with periods of particularly low stress. The most striking example was that of a 30-year-old Asian woman, whose hair sample included a band of grey measuring 2 centimeters (0.8 inches), beneath which it returned to its former color. As it turned out, the gray section matched up exactly to a two-month period of high stress, during which she separated from her husband.
Another participant regained the original color of his hair during a two-week vacation, indicating just how quickly this transformation can occur. In fact, the researchers found evidence that a hair can turn completely gray, or undergo a full reversal of that process, in as little as 3.7 days, although on average it takes about three months for these changes to take place.
It’s important to note that the team only looked at individual hairs, and no one is suggesting that an entire head of gray hair can be restored to its original color simply by relaxing for a few weeks.
Yet the study authors write that their finding nonetheless provides categorical proof that “human aging is not a linear and irreversible biological process and may, at least in part, be halted or even reversed.”
Achieving a significant restoration of hair color is likely to be extremely difficult without targeted drugs, although now that the proteins responsible for the graying process have been identified, it may be possible to begin developing pharmaceuticals for this purpose.
[H/T: New Scientist]