Pizza Doesn’t Give You Acne—But What About Sugar?

Among the die-hard skin-care fans on reddit.com’s community SkincareAddiction, there’s a prevailing belief that committing to a dairy-free diet will majorly affect the prevalence of acne. Take the user andbutter, who writes that “giving up dairy was the best thing I’ve done for my skin.” Or the user umidkmybffjill, who claims, “I cut out dairy and switched to almond milk (not soy because I read it can negatively affect skin as well) about 3 years ago and my skin is better than ever!”

Dairy-free is far from the only diet prescribed as a cure-all for problematic skin. An abundance of pimple-treatment advice online has acne sufferers trying a whole variety of unproven diets and taking up anecdotal stories of improvement as gospel. Some people who go on the low-carb ketogenic diet claim that ridding their diet of sugar helps keep acne and oily skin at bay. Conversely, others are convinced that a low-fat diet rich in unrefined carbohydrates such as potatoes almost entirely eliminates acne. A small 2016 study found that 46 of the study’s 49 dermatologic patients believed that diet affects acne, with greasy foods as the No. 1 suspected culprit.

With this abundance of often conflicting advice, acne sufferers’ confusion over treatment tactics seems inevitable. The American Academy of Dermatology, or AAD, doesn’t currently recommend diet changes to manage acne, citing lack of sufficient data. And it doesn’t help that misinterpretations of 1960s-era research has acne sufferers throwing their chocolate bars in the trash. Multiple correlations between breakouts and diet have been found, but these correlations are more complicated than Reddit advice columns may lead people to believe. Often, it’s not a one-to-one scenario.

The most promising correlation is, perhaps surprisingly, sugar. “Multiple studies have now found that diets with a high glycemic load can trigger acne in certain persons,” says Rajani Katta, a clinical professor of dermatology at the University of Texas at Houston. Anne Chapas, the founder of Union Square Laser Dermatology, agrees. “The spikes in blood sugar which arise from eating high-glycemic foods causes oil production, which in turn causes acne,” she says. “We know that those cause a harmful hormonal environment.”

High-glycemic foods are foods such as white bread, potatoes, and white rice, which all cause a quick rise of glucose in the blood, or what is more colloquially known as a blood-sugar spike. This blood-sugar spike also causes an increase of insulin, and that insulin spike, in turn, stimulates the activity of the hormone androgen and a protein known as insulin-like growth factor 1. These act together to encourage the growth of skin cells and the production of an oily glandular secretion called sebum. And that combination of skin growth and oil production—you guessed it—can lead to acne.

That said, a lot of fried foods are high in processed carbohydrates and sugar. French fries, for example, might exacerbate acne not because the potatoes are fried, but because potatoes cause a blood-sugar spike—and it’s obvious what that leads to.

The same goes for gluten. According to Chapas, the protein found in wheat-based products such as bread and pasta doesn’t itself cause acne. Rather, it’s the high-glycemic, processed carbohydrates that cause heightened glucose levels in the blood. Chocolate, which people commonly believe causes acne, only appears that way because it’s typically an ingredient in a highly processed, sugary food. “It’s not chocolate per se, but it’s high-glycemic food,” Chapas says.

As gluten-free diets continue to surge in popularity, and concerns around “inflammation” grow, it can only become more tempting to resort to a restrictive diet to cure ailments, acne included. But “while diet can impact your skin in certain conditions, a lot of the information that’s out there on the web is not based on sound scientific research,” Katta says. “You should not be making changes to your diet based on anecdotal evidence. One success story is not enough to prove something will work for everyone.”

While avoiding certain foods may help some people with their acne issues, “some people have a genetic tendency toward acne, and teenagers are especially susceptible because of hormonal changes,” Katta notes. So if you want to decrease your blemish count, chilling out on the Mountain Dew and Twizzlers might help. But no promises yet.

We want to hear what you think about this article. Submit a letter to the editor or write to [email protected]