Acne is often considered a teenager’s affliction, a scourge most kids outgrow along with driver’s education, pep rallies and prom. Although puberty’s hormone roller coaster makes teens more susceptible to pimples, millions of adults get them, too—even those who didn’t battle blemishes in their youth.
Several factors, such as chronic stress and pore-clogging cosmetics, can cause breakouts. However, dermatologists and nutritionists have realized that one major cause should not be overlooked: diet. Many people have cast off the chocolate-causes-zits idea as an old wives’ tale, thanks to a famous 1969 report that claimed to disprove the food-blemish link. But several studies show that today’s typical American menu—packed with simple sugars and refined carbohydrates—may indeed be enemy number one when it comes to acne.
Population studies of Western and non-Western cultures seem to prove this notion. In a report published in Archives of Dermatology in 2002, researchers noted that about 50 percent of adults in Western nations suffer from acne. However, when examining two separate population groups—one in Paraguay, the other in Papua New Guinea—that stick to their traditional diets of plants, tubers and wild game, doctors found zero cases of acne in either.
They acknowledged that genetics play a part in acne but deemed it highly unlikely that blemishes could be completely nonexistent thanks to genes alone. The researchers believe that the absence of unhealthy American food in these cultures contributes significantly to the peoples’ clear skin. As additional evidence, they cited previous studies of Eskimos, Okinawan islanders and rural Brazilian and South African tribes that show that acne became an issue among these groups only after each began incorporating Western foods into their diets.
The glycemic connection
So how exactly might low-nutrient, processed foods contribute to acne? Besides offering few if any nutrients, white breads, potato chips, pastries and candy bars take little effort for the body to digest. Therefore, they’re unleashed rapidly into the bloodstream, causing insulin levels to skyrocket.
This turn-and-burn process scores these foods high on the glycemic index, “which indicates the extent to which particular foods and beverages push insulin production,” says Dr. Alan C. Logan, naturopathic physician and coauthor of The Clear Skin Diet (Cumberland House, 2007) and Your Skin, Younger (Cumberland House, 2010). “And higher insulin production encourages the production of sebum.” Sebum is the oily substance that flushes out toxins through the pores. But when churned out in excess, sebum builds up and turns into a breeding ground for the bacteria that clog pores and cause pimples.
What’s more, insulin surges can trigger the body to release certain hormones that also prompt sebum production. “Androgens—so-called ‘male’ hormones including testosterone and dihydrotestosterone—are essential to the acne process,” Logan says, adding that the stress hormone cortisol also ramps up sebum output. He points out that each person’s body chemistry is different, so it’s possible for a person to have elevated insulin and hormone levels and no pimples.
What not to eat for clearer skin
According to Logan, the high-glycemic foods most likely to trigger acne include sugary soft drinks, processed carbs like white pasta and bagels, and saturated fat-loaded foods such as chicken fingers and onion rings. Dairy’s impact on acne has been somewhat controversial. Although milk in particular is low glycemic, a large Harvard School of Public Health study noted a correlation between drinking milk and acne among teenage girls. But Logan says this link is by association only and that milk may not be a direct cause.
“Some researchers theorize that milk can encourage insulin release and/or directly elevate blood levels of growth hormone, which in turn promotes sebum production,” Logan says.
Just as high-glycemic diets can trigger acne, low-glycemic foods—those that take longer to digest and don’t ratchet up insulin production—have been shown to be beneficial as a clear skin diet.
“In two published studies, subjects who followed a low-glycemic diet and avoided processed carbohydrates reported an average of 22 fewer acne lesions after three months,” Logan says. “The low-glycemic diet has also been linked to a reduction in acne-promoting hormone production.”
Load up on these foods instead
“As a general rule, a Mediterranean diet that’s rich in deeply colored fruits and vegetables, unprocessed grains, fish and seafood is great for staving off acne,” Logan says. Along with being low glycemic, these foods for healthy skin offer acne-fighting nutrients such as antioxidants and healthy fats that tame inflammation. “The anti-inflammatory fats in olive oil and omega-3 fatty acids from fish and seafood are great for the skin,” Logan says.
“I also recommend tomato juice, because it’s rich in the antioxidant lycopene and can lower acne-promoting hormones. Green tea lowers dihydrotestosterone linked to acne. As far as dairy is concerned, first experiment with yogurt and then try reintroducing cheese and milk over time.”
Just as foods can contribute to acne, foods can also help you “eat away” your acne. The best acne-fighting results can be achieved by avoiding high-glycemic foods and eating more low-glycemic foods.