Changes in diet can sometimes lead to hair loss

Dieters hoping to lose weight are discovering they're losing something else -- their hair.

The little-talked-about secret of the dieting industry is that a successful diet can also trigger hair loss.

As Americans struggle with obesity and tackle countless fad diets, some dermatologists say they are increasingly hearing complaints from perplexed dieters about thinning hair.

After Esther Sokol, a New York City records manager, lost nine pounds on the Atkins diet a few years ago, her hairdresser noticed her usually thick hair was beginning to thin. It was only after talking with doctors and hair experts that she learned her diet was the likely culprit.

"Diet was the only major change I'd made," says Ms. Sokol.

Hair loss can be triggered by a variety of factors including pregnancy, stress, surgery and age-related hormonal changes, to name a few.

But few people realize that weight loss can also cause hair to shed, likely due to a nutritional deficiency. Although iron deficiency is often associated with diet-related hair loss, a range of nutrient deficiencies can result in thinning hair, dermatologists say.

Changes in levels of zinc, magnesium, protein, essential fatty acids and vitamins D, B and A can all trigger episodes of shedding hair. The problem affects both men and women, but women are more likely to notice it and seek treatment, say doctors.

The fact that so many different nutrients can be the culprit in hair loss means any diet can take a toll on the tresses.

The threat of thinning hair shouldn't discourage patients from losing weight, but it should convince them to avoid fad, quick-reduction diets, says Wilma Bergfeld, head of clinical research for the department of dermatology at the Cleveland Clinic.

Such diets often lack proper nutrition, and rapid weight loss in itself is a stress on the body and can also trigger metabolism changes that affect hair growth.

For hair health, doctors say the best weight-loss plans are reduced-calorie diets that promote gradual weight loss with healthful foods from all of the food groups.

Diets low in protein and iron, such as vegetarian diets and very-low-fat diets, often result in deficiencies. But high-protein diets like Atkins that initially discourage fruits and vegetables can also trigger hair loss, says Dr. Bergfeld. The typical patient complains of thinning hair after losing about 20 pounds in a relatively short period of time, she says.

"We see it all the time," says Dr. Bergfeld. "If you start eating only one thing and you're not well balanced, you get into trouble."

A spokesman for Atkins referred questions to the company's Web site, which addresses hair loss in its frequently asked questions section, noting that any weight-loss plan can trigger hair loss.

The site contends the Atkins diet is the "least likely" to cause hair loss. However, dermatologists say no scientific study has ever determined whether certain diets are more or less likely to cause hair loss.

In a healthy person, hair typically grows about an inch every two months. Hair has a three-phase life cycle -- the growing phase can last two to five years.

A second, less-active phase lasts only about six weeks.

A final resting phase lasts three to five months, before the hair falls out and new hair grows in. About 15 percent of hair follicles are in the resting phase at a time.

Abrupt changes in nutrition can disrupt the hair-growth cycle, causing hair follicles in the growing phase to convert to the resting phase too soon. This can mean a 20 percent to 30 percent or more increase in the number of daily hairs shed.

For many people, diet-related hair loss is temporary and may last only about two to six months. Once a person starts eating a more balanced diet, hair eventually comes back. In some people it may take one to two years to regain a full head of hair, dermatologists say.

Some dieters aren't even that lucky. A hair-shedding episode triggered by dieting may become a chronic problem if the dieter has a genetic predisposition for thinning hair, says Dr. Bergfeld and other doctors.

In addition, hair loss triggered by dieting can be exacerbated by hormonal changes, stress or medications -- sending patients into a chronic cycle of hair shedding.

Ms. Sokol says she stopped the diet and has since regained the weight -- but her hair has never recovered. She says that if she had been aware of the link between weight loss and hair loss she probably wouldn't have tried the diet.

Dermatologists say they often advise dieters to take a multivitamin with iron and keep weight loss to a pace of one to two pounds a week.

Dieters with a family history of thinning hair or baldness should be especially careful about proper nutrition and slow weight loss.

Patients considering obesity surgery, which often results in rapid weight loss, should also talk to their doctor about ways to protect their hair.

In addition to nutrition supplements, patients who experience thinning hair after dieting or for other reasons are advised to avoid chemical treatments like bleach or permanents that weaken hair.

Minoxidil, the active ingredient in the topical treatment Rogaine, is often recommended for chronic hair loss, although it doesn't work for everyone and has to be used consistently or the hair shedding will return, notes Brooklyn dermatologist Morris Westfried, medical director of the New York Hair Loss Center who published one of the first reports on minoxidil.

For men, the oral medication Propecia may also help improve thinning hair.

Hair extensions and transplants are also an option, but they can be expensive.