A 38-year-old businessman surnamed Lee, who declined to give his full name, has done almost everything to slow down his hair loss.

Having long used a special shampoo made of natural ingredients, he recently bought an electronic device that emits laser beams and stimulates the scalp.

“I heard there is no way to replace the hair that has already gone. I just want to keep my remaining hair,” said Lee, whose father became bald in his 40s.

Many people may agree with Lee that new hair cannot grow on a bald scalp as it has lost the follicle stem cells that make new hair.

However, a team of U.S. doctors found Tuesday that bald and haired scalp tissue contained equivalent amounts of preserved stem cells and a newly identified stem cell defect, rather than any loss of stem cells themselves, caused genetic hair loss. 

Common baldness is characterized by a marked decrease in hair follicle size, which leads to thinning hair both in men and women.

In a bald scalp, the study found, a malfunction occurs during the process by which hair follicle stem cells turn into hair-producing progenitor cells.

The team hoped that it may be possible to cure baldness by restoring the normal function of these cells.

“The follicles that make hair don’t go away completely, but they become miniaturized, to the point where the hair they normally make to replace hair when it naturally falls out becomes microscopic and therefore invisible,” study co-author George Cotsarelis, chairman of the dermatology department at the University of Pennsylvania School of Medicine, said in an interview.

“There are still just as many stem cells in the bald scalp that can make hair as there are in the normal haired scalp, and that was an important and surprising finding.”

For the study, the team studied human scalp tissue ― bald and haired ― discarded during hair transplant procedures performed on 54 white men between the ages of 40 and 65.

The findings, published Tuesday in the Journal of Clinical Investigation, may someday lead to new targets for treatment of baldness, which affects millions of people worldwide, they said.

In Korea, an estimated 10 million people suffer from hair loss. Especially, those in their 20s and 30s have surged 30 percent between 2001 and 2008, according to the latest government data.

“Previously we thought the stem cells were gone, and if that was the case it would be very difficult. But because they are present it should be possible to treat,” said Cotsarelis.

However, those hoping for a breakthrough in hair-loss treatments anytime soon still need to wait.

Experts cautioned that there is no treatment around the corner, saying that it often takes decades to take something from the lab to the clinic.

By Lee Ji-yoon (jylee@heraldcorp.com)