Acne culprits: Chocolate or sugar?
When it comes to diet, there's good data to suggest that high glycemic index foods -- rich in refined carbohydrates and sugar, including sugary drinks and processed breads and snacks -- are bad for acne-prone skin. These foods cause a spike in blood sugar, which increases production of insulin, an insulin-like growth factor and hormones known as androgens, which results in more sebum production, Farris explained.
Sebum is an oily substance secreted by the sebaceous glands that keeps skin moist. When the glands produce too much sebum, the oil can combine with dead skin cells and become trapped in pores. This leads to blackheads, whiteheads and pimples.
"Spikes in insulin are acne-genic, so we don't want high-glycemic diets," Farris said. "We've connected the dots there ... but we haven't completely connected the dots on chocolate."
In fact, kids who eat chocolate candy and break out afterward might attribute their acne to chocolate, but in reality, their pimples may proliferate because these junk foods are sugar-rich and cause blood sugar and insulin spikes.
"The chocolate your average kid consumes is a small amount of chocolate wrapped around a piece of gooey caramel or in some ice cream. The chocolate is probably less of an influence on that kid than the rest of the junk food they're eating," Farris said.
Evolving research reveals breaking news on breakouts
Although previous research has dodged a link between chocolate and acne (one older studywas actually supported by the Chocolate Manufacturers Association of the USA), more recent studies show that it may be a contributing factor.
In one study, participants were randomly assigned to eat a chocolate bar or 25 jelly beans, both of which provided the same glycemic load, an indicator of how high blood sugar will rise after each portion of food. All patients received both "treatments." Interestingly, jelly beans didn't have an effect on acne. But when people ate chocolate, their pimples increased.
"We found that, on average, people had about five more pimples with the ingestion of chocolate," said study author Dr. Gregory R. Delost of the Department of Dermatology at University Hospitals, Cleveland Medical Center. "Some people might say, five pimples, no big deal, but if someone is getting ready for their high school dance ... then five pimples is definitely clinically relevant in that situation."
Is dark chocolate healthy ?
Based on his findings, Delost is convinced that chocolate can make your acne worse, though he admits that by giving participants milk chocolate, he didn't tease out an important variable. "There's a lot of literature about milk causing acne, so that would be the big fault in my study."
But even when both milk and sugar are taken out of the equation, chocolate appears to play a role in pimple formation.
In one 2016 study involving 25 people, researchers investigated whether an ounce of 99% cacao dark chocolate, without added sugars or milk, would cause acne to worsen in acne-prone maleswhen consumed daily.
After four weeks, researchers found a statistically significant increase in both comedones (also known as blackheads) and pimples when compared to baseline.
"We did not conclude that chocolates cause acne, as this condition is caused by multifaceted factors," said study author Dr. Pravit Asawanonda, professor and chair of dermatology at Chulalongkorn University in Bangkok, Thailand. But "our study suggests that dark chocolate 'exacerbates' acne in terms of lesion counts."
The study did not answer whether chocolate can cause acne in those who are not acne-prone. It was also small and did not include a control group or female participants. "Even so, I think it does suggest a link between dark chocolate and acne," Farris said.
In milk chocolate, the dairy sugar might be the culprit, but in the case of dark chocolate, the various fatty ingredients could be involved, Asawanonda explained.
Interestingly, cocoa's flavonoids are known to be anti-inflammatory, a purported skin benefit, but dark chocolate also contains cocoa butter, which consists of fats known as oleic acid and stearic acid. According to researchers, oleic acid has been shown to influence pore clogging in animals.
"Can eating chocolate cause an outbreak of acne? Yes," said Dr. Brian Berman, emeritus professor of dermatology and cutaneous surgery at the University of Miami, who conducted a similar study, though unlike Asawanonda's study, his was double-blinded and placebo-controlled. It showed that ingestion of pure 100% chocolate in the form of capsules, devoid of milk and sugar, caused a greater increase than placebo in the number of inflammatory and non-inflammatory acne lesions in young men who had a history of acne but who had no acne lesions at baseline.
Berman's study had only 14 participants, and he admits that it would be better to have evidence involving more participants, especially females. Women are often excluded from acne studies because acne can get worse during menstrual cycles, and this can confound results, Delost explained. But Berman said, "the findings are consistent with the real-world experience of many patients."
In addition to the fat component of chocolate, which has been linked to blackheads, some research suggests that chocolate may have pro-inflammatory influences in the skin, which could contribute to inflammatory acne, characterized by red papules and pustules, especially in the presence of known acne-causing bacteria, Delost explained.
"The pathogenesis of acne is complicated. ... It's not just one thing," Farris said. "There's a buildup of skin cells at the opening of the hair follicle that causes sebum to be trapped inside. Bacteria proliferate in the sebum and triggers inflammation around the hair follicle. You've got this four-pronged pathogenesis, and that's what makes it so complicated to tease out independent variables. But nutrition plays a role. I think we can safely say that avoiding chocolate addresses only one piece of a very large puzzle."
The bottom line
While we wait to see what future studies conclude, experts say knowing how your own skin reacts to chocolate will give you all the information you need.
Keeping a food journal can help you determine whether your acne worsens when you eat chocolate, something Delost advises for some of his patients.
But unfortunately, that may mean giving up the indulgence, at least some of the time. "Everybody has their own triggers. If chocolate breaks you out, stop eating it," Farris said.
Berman agreed. "It's simple. If you experience acne outbreaks after eating even moderate amounts of dark chocolate, unfortunately, limit or stop eating chocolate."
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