The Truth About Graying Hair

Gray hair is in the news, although this isn't a result of the tanking home mortgage industry or the prolonged war in Iraq. Rather, journalist Anne Kreamer has a new book about her bold decision to stop dying her hair at age 49 and to let it go gray, naturally.

She scored articles in Time, Newsweek and elsewhere this month, written, perhaps, by women faced with this same terrifying decision. Pundits are now debating whether Hillary Clinton can win the election with gray hair.

While it is surprising that an entire book can be dedicated to this topic—which does give me confidence that the time is right for my book about my quest to stop biting my nails—this does provide an opportunity to address the pervading myth that hair can turn white or gray overnight from fear.

Hair can only change color as fast as it can grow. And while stress can play a part in gradual graying, the reason is usually genetic.

The stuff of legends

There has never been a documented case of a person whose hair has suddenly turned white from fear or any terrifying stimulus other than hair dye.

There are legends. Thomas More's hair was said to turn white the night before his execution in 1535. His tumultuous final days as advisor to King Henry VIII are well documented in the annals of English history and dramatized in the play "A Man For All Seasons." The bit about the hair turning white, however, came after he died, sort of like George Washington chopping down the cherry tree.

A similar legend surrounds the beheading of Marie Antoinette and even the wife of a modern-day leader, Barbara Bush, whose hair has been said to turn white from the death of her baby daughter in 1953.

Closer to home, I apparently caused my mother's gray hair and my father's baldness.

Biology of hair

Each hair is a lifeless strand of keratin, a protein, with no capacity to transmit nutrients or information. The root of each hair resides in a hair follicle, sort of like a hair factory. Hair growth is essentially the addition of new keratin to the bottom of the strand of hair. Follicle cells called melanocytes make melanin, the same pigment that gives skin its color. Melanin colors the keratin and thus the hair.

As we age, melanocytes stop producing melanin, leaving the hair to become white or grayish. The timing is almost entirely genetic, although poor nutrition or stress can damage the follicle cells and compromise their ability to make melanin. Smoking, too, can cause premature graying.

Most people gray slowly, over decades, as follicle after follicle starts producing gray hair. We have 100,000 or so hair follicles, so this can take some time.

People have gone gray in a few months, not from fear but from the normal process of aging. Sometimes all the hair follicles will start producing gray hair roughly at the same time. So in a few months, dark tips are cut away and only the gray is left.

Rare disease, not fear

There is a rare form of sudden baldness, called diffuse alopecia areata, that will cause only pigmented hair to fall out, leaving gray and white hairs behind. The inattentive casual observer might assume that a person afflicted with diffuse alopecia areata has suddenly gone completely white. Look closer and you'll see that person has also lost half of his or her hair. Still, this takes a couple of weeks, not overnight.

How did the myth get started? It could be that time flies. I myself only "knew" folk singer Arlo Guthrie from pictures on his early albums from the 1960s and '70s. When I went to a concert recently and saw his lush mane of long, white hair, I felt that Arlo had aged overnight.

Wonderfully enough, after his first song, Arlo even said: "I know what all of you are thinking: 'Man, he got old.' Well, guess what? You got old, too."

Christopher Wanjek is the author of the books “Bad Medicine” and “Food At Work.” Got a question about Bad Medicine? Email Wanjek. If it’s really bad, he just might answer it in a future column. Bad Medicine appears each Tuesday on LiveScience.