The truth about stretch marks: here's your guide to banishing the marks of physiques past

Okay, so maybe the problem doesn't rank up there with world hunger, air pollution, global unrest or even paying your rent on time, but stretch marks--those unattractive reddish streaks that show up when your body changes too quickly--can be an unsightly nuisance. When you're committed to eating right and maximizing your workouts to look and feel your best, it's kind of a drag to develop these hard-to-get-rid-of lines (basically, scars that result from overtaxing your skin's elasticity) just as you're really starting to make some progress.

While most experts agree on the causes of striae atrophicae (the medical term for stretch marks), they have widely divergent ideas about how to best prevent and treat them. The following should help you separate fact from hype and expand your understanding of this common but nonetheless irritating condition.

birth of "those lines"

According to facial plastic and reconstructive surgeon Mark A. Erlich, MD, clinical assistant professor at New York Medical College, stretch marks are caused by "a rupture of elastic tissue in the dermis [skin] along linear tracks, which causes purple lines that fade to become white, depressed surface irregularities. They're typically caused by rapid growth, weight gain, pregnancy and also by weight loss." Paul Carniol, MD, clinical associate professor, University of Medicine and Dentistry, New Jersey, and vice president of the International Society of Cosmetic Laser Surgery, offers a slightly different take on the situation: "The weight gain is the actual cause of the stretch marks--this is when the damage is done. When you lose weight, the skin becomes looser. This often makes the marks become more noticeable."

Board certified clinical and research dermatologist Nicholas Perricone, MD, FACN, assistant clinical professor of dermatology at Yale University School of Medicine and author of the New York Times bestseller The Wrinkle Cure (Warner Books, May 2001) recommends that an active person of either sex gain no more than 2% of his or her total body weight per month to avoid developing many stretch marks. This would translate into a 140-pound woman putting on no more than 2.8 pounds (2% of her bodyweight) in a 30-day period. He also believes a diet with adequate amounts of protein may help minimize stretch marks. Protein helps the skin repair itself, and thus, theoretically, makes the dermis more supple.

Typically, women complain of stretch marks mostly on the abdomen, breasts and buttocks. It takes about a year or more for the "fresh" red marks to fade to white/silvery streaks. Many experts agree that there is a genetic tendency toward stretch marks (if a parent or sibling has them, you probably will, too), and age could be a factor, as well. Ironically, notes Perricone, you may be more likely to develop stretch marks in your teens, 20s and 30s, when your skin is more elastic. Rapid cellular turnover during the growth years and pregnancy causes the collagen and elastin producing cells to become overburdened, resulting in faulty production of collagen and elastin. In your 40s and beyond, your skin is generally looser on your body, which means you're less likely to develop the marks.

In addition, there is some professional debate about whether some skin types are more prone to developing stretch marks. Perricone, for example, asserts that many fair-complexioned women, whose skin is generally thinner than that of men (due to them having less testosterone) tend to suffer more from the "crepe-y" look when their marks turn white. And, while Carniol believes that ethnicity and skin tone do not play much of a factor, Richard Silverman, MD, assistant professor of surgery at the University of Massachusetts Medical School, based at St. Elizabeth's Medical Center in Boston, disagrees: "I would think skin type would make a difference. People of English or Irish descent with light skin may have silvery stretch marks that are less noticeable, while individuals of different ethnic backgrounds who are darker complexioned tend to develop marks that stay dark and more visible over time." Yet, regardless of your sex, skin type, diet or genetic predisposition, as Silverman says: "There is no surefire way to avoid stretch marks. Gradual growth" he adds, "may aid in minimizing them. It isn't clear whether or not skin moisturizers will help in this endeavor, but they wouldn't hurt."

creams, gels and lotions

Manufacturers claim that cocoa butter and myriad other herbs and topical products can prevent or get rid of stretch marks. Do these products have any merit? Again, there is ongoing controversy. What you should remember, however, is that cosmetics are not subject to the same stringent FDA standards that medications must meet. In short, these products may or may not have value. Evaluate them on a case-by-case basis, rather than as a whole.

When you explore the plethora of topical and herbal remedies on the market, Carniol suggests visiting a product's website, contacting the manufacturer and asking them to send a small sample, along with studies that indicate the effectiveness of the product. Perricone, who has his own product line, NVPerricone, M.D. Cosmeceuticals, comes from a somewhat different place. He has been granted a patent on DMAE (dimethylaminoethanol), a firming ingredient found in the human body, salmon and other natural sources. Perricone claims that DMAE contains an anti-inflammatory property that lessens redness in fresh marks and makes the skin tighter, reducing the "crepe-y" look of older stretch marks and making the skin smoother overall. Still, the dermatologist adds that some cosmetic aspects of the DMAE action last only 24 hours.