Let us start by saying: Gray hair is something that happens to us all eventually, and it shouldn’t be feared or frowned upon. Embrace the beauty of those silver strands, or you can always cover them up with a gloss if you choose.
As for premature graying, we know that stress can do a number on the body: When it comes to hair, the theory is that long-term psychological stress can increase levels of oxidative stress, which can then contribute to grays. Research on mice has also found that stress starts a chemical process that depletes the stores of pigment-producing cells, thus resulting in a faded hue.
Although, the road to gray hair is generally seen as a one-way course: Once those strands lose their color (stress-induced or otherwise), you can’t expect to return to the vibrant strands of your youth. However, a recent study from researchers at Columbia University Vagelos College of Physicians and Surgeons says we should rethink the notion. According to the research, gray hair may be reversible—albeit temporarily.
Wait, can you reverse gray hair?
The researchers were able to analyze how the hair shaft changes over time. See, under an intense microscope, you can tell a lot about a hair’s journey: Each strand is made up of dead cells, but those cells are very much alive before they’re uprooted for the scalp. “While hairs are growing, cells receive chemical and electrical signals from inside the body, including stress hormones,” the report reads. When those signals occur, it can cause changes in the proteins and molecules inside the hair shaft—and those changes remain there even once the strand grows out of your head. Neat, no?
Each shift that happens inside the strand offers a little message: “Just like tree rings hold information about past decades, and rocks hold information about past centuries, hairs hold information about past months and years,” the report continues. That’s why the researchers wanted to measure these hair pigmentation patterns in tandem with times of stress and see if any of the changes matched up.
Participants were asked to identify the most and least stressful events over the last 12 months, mark them on a map, and connect the dots to create a visual timeline of ups and downs. Then they measured each hair to match the specific weeks or months along the stress profile. It turns out, stressful moments (like marital conflicts, according to one participant) were associated with loss of hair pigment, whereas during moments of bliss, the hair regained its pigment.
“There was one individual who went on vacation, and five hairs on that person’s head reverted back to dark during the vacation, synchronized in time,” says senior author Martin Picard, Ph.D., in a news release.
What does this mean for us?
TL;DR? Graying hair may be more dynamic than we previously thought: The pigment may bounce back and forth (even though you may not be able to see it with the naked eye), and stress seems to be a significant factor. The changes in color weren’t so stark—it’s not like a whole head of silver regained its pigment—but how stress affects each individual strand at the cellular level is interesting to note.
It’s certainly something to keep in mind in terms of delaying premature graying. “But we don’t think that reducing stress in a 70-year-old who’s been gray for years will darken their hair or increasing stress in a 10-year-old will be enough to tip their hair over the gray threshold,” says Picard. But for some on the cusp, stress may be the final straw for those strands to topple over the edge.