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Why Is Acne More Prevalent Than Ever?
Back in the 1990s and early 2000s, doctors from the United States and Venezuela conducted acne exams on more than 1,300 people living in two remote sections of Paraguay and Papua New Guinea. The results of those exams appeared in a JAMA Dermatology paper and they were, to quote the paper’s authors, “astonishing.”
The doctors turned up virtually zero cases of acne among rural men and women. The contrast between the clear complexions of the people in the study and the high occurrence of acne in the modernized world was so striking that the study authors wrote that the discrepancy “cannot be solely attributed to genetic differences among populations but likely results from differing environmental factors.”
In the U.S., acne pimples are a near-universal affliction among teens and are increasingly common among adults. By some estimates, nearly all American kids have to deal with acne pimples from time to time. Roughly one in three women in their thirties struggles with acne, along with 20% of men, according to a study in the Journal of the American Academy of Dermatology.
“Acne is not just for teens — there are extraordinary numbers of adults with acne, and the numbers seem to be going up”
While accurate historical data are hard to come by, evidence suggests acne rates are on the rise among both young people and adults. A 2016 study from the University of Colorado found that, between 1990 and 2010, acne rates increased 11% among U.S. teens. Recent research on adult acne has also turned up evidence that it’s an “emerging issue,” especially among women.
“Acne is not just for teens — there are extraordinary numbers of adults with acne, and the numbers seem to be going up,” says Dr. Adam Friedman, a professor and interim chair of dermatology at the George Washington University School of Medicine and Health Sciences. “I treat more adult acne patients than teens, and it’s mostly women in the thirty to fifty age range.”
Figuring out the causes of acne’s apparent surge is tricky. Some researchers have speculated that a “Western diet” packed with meat, dairy, refined grains and sugar could be producing a surge in hormones that contribute to acne. Obesity and diabetes, which remain at epidemic proportions in the U.S., are also associated with acne-promoting hormone shifts, so could help explain rising rates.
But Friedman says it’s also possible that acne treatments are to blame: They could be unbalancing the skin’s bacteria populations — also known as the skin microbiome — in ways that promote pimples and breakouts. “It’s only during the last 50 years that teenagers started using all these acne products” — antibacterials, but also benzoyl peroxide creams and salicylic acid treatments, to name just a few — “and now we’re seeing massive numbers of adults with acne,” Friedman says. While these treatments can help dry up or clear away zits in the short term, it’s possible they also “dysregulate” the skin’s microbiome in ways that persist into adulthood and promote acne, he says. “What we put on our skin can improve or disrupt the survival of these microorganisms. This is something we didn’t know before, but we’re paying attention to now.”
A small study published last year in the Journal of Investigative Dermatology found a popular acne treatment called Isotretinoin — which is a derivative of vitamin A — can cause a drop in some potentially acne-causing bacteria while bolstering the populations of others that may protect against acne. That’s all good.
On the other hand, popular antibacterial acne treatments such as clindamycin and macrolides seem to wipe out bacteria more indiscriminately, which could be problematic. “Antibiotic treatments are still the first line of prescription drugs used for acne treatment, but they kill all strains similarly, bad ones and good ones as well,” says Huiying Li, an associate professor in the Department of Molecular and Medical Pharmacology at the David Geffen School of Medicine at UCLA. For example, research has linked the bacterium Propionibacterium acnes, or P. acnes, to the development of acne. According to some of Li’s work, P. acnes is more or less equally common among people with acne and those without. It just depends on the “strains” of P. acnes that are present on a person’s skin. “Not all the P. acnes are bad,” Li says.
She explains that beneficial strains of P. acnes help keep the skin appropriately acidic, which bolsters its defenses against pathogens and could, at least in theory, guard against acne. These theories require more exploration. “But in general, you want to maintain balance among the microbes on your skin.” Avoiding products that meddle with this balance could be helpful.
Acne treatments aren’t the only thing that could be messing with your skin’s microflora. “Over-washing can definitely disrupt the skin’s microbiota,” says Friedman. Beauty masks, makeup, and UV rays can also influence the bacterial population.
While the science of microbiomes is in its infancy, Friedman recommends a less-is-more approach to skin care: Unless a dermatologist has advised otherwise, using a gentle cleanser once or twice a day, coupled with a non-comedogenic moisturizer, is the way to go. Mild cleansers and many moisturizers act as “prebiotics,” meaning they tend to foster an environment that allows healthy skin microbes to thrive.
“Acne is not normal or healthy physiology,” says Friedman. “It is chronic inflammation in the skin that can have long-lasting consequences. But there’s a lot about it we still don’t understand, especially when it comes to the microbiome.”