Editor’s note: This story was originally published Apr 20, 2023.

What is the real cause behind why our hair turns gray?

Is it stress? Is it the environment we live in? Is it that some are destined to become silver foxes quicker than others?

After studying mice for two years, scientists say it is none of those things.

What are the benefits of hair oiling? Here’s what you need to know

Why does our hair turn gray? The New York Times reported, “Our hair turns gray when melanin-producing stem cells stop functioning properly.”

The Nature journal published a study in which scientists spent two years tracking individual cells in the fur of mice in order to determine how hair turns gray.

Researchers discovered that the pigment producing part of a stem cell would change as the mice would mature.

The study detailed, “The melanocyte stem cell system fails earlier than other adult stem cell populations, which leads to hair greying in most humans and mice.”

Mayumi Ito, author of the study and dermatology professor at New York University’s Grossman School of Medicine, said, “This is a really big step forward understanding why we gray.”

Discover Magazine reported that white and silver hair have no melanin, and gray hair has small amounts of melanin as the hair is starting to lose its pigment due to aging.

Using Beethoven’s hair, scientists determined the real cause of the composer’s mysterious death

Does stress turn your hair gray? News in Health reported that a 2020 study found that stress can give you gray hair.

“When we started to study this, I expected that stress was bad for the body — but the detrimental Impact of stress that we discovered was beyond what I imagined,” Dr. Ya-Chieh Hsu, who led the study, said. “After just a few days, all of the melanocyte stem cells were lost. Once they’re gone, you can’t regenerate pigments anymore. The damage is permanent.”

Despite this discovery, Harvard Health reported that stress doesn’t actually change the color of your hair but can trigger telogen effluvium, which is a condition that results in hair loss.

Telogen effluvium reportedly doesn’t result in balding, as the hair does grow back, but it can lead to thinner hair than a person may have had before developing the condition.