Chocolate is one of the foods that people frequently cite as one that makes their acne worse. Unfortunately, it’s also delicious (enough so to warrant a cutesy colloquial terms for those who are hooked: chocoholic.) But the research about whether or not acne sufferers are actually negatively impacted by chocolate isn’t particularly definitive. In fact, there are surprisingly few studies, given that it’s so often implicated in acne outbreaks.
Research Showing that Chocolate Doesn’t Affect Acne
There is an early and oft-cited study done in 1969 that used 65 subjects who ate either a chocolate bar with ten times the chocolate of a regular bar or an identical bar without chocolate every day for a month. After a three-week break, the groups switched. The researchers examined the participants every week throughout the study and counted skin condition changes if they were 30% better or worse than they were at the start. At the end they concluded that there was no link between chocolate and acne (The Journal of the American Medical Association, 1969).
But as a 2011 Letter to the Editor of Clinics of Dermatology that critiques the study points out, the participants were about half and half male prisoners and adolescent boys and girls, and the researchers didn’t account for variables like age, diet, gender, stress, and medical conditions, among several others. It was also “made possible by” the Chocolate Manufacturers’ Association of the U.S.A. (Clinics in Dermatology, 2011).
Two trials on college students found that participants had no increase in acne after eating chocolate, milk, or roasted nuts. But these studies were small, weren’t controlled, had short follow-up times, and used insufficient statistical analysis (American Family Physician, 1971; Missouri Medicine, 1965).
Research Showing that Chocolate Might Affect Acne
Another small study, done in the Netherlands, tested seven healthy participants’ blood before and after they ate 1.7 ounces of chocolate with 30% cocoa every day for four days. They then introduced Propionibacterium acnes and Staphylococcus aureus bacteria, both of which contribute to acne, to the blood cells. The blood cells produced more of the immune system inflammation marker interleukin-1b when exposed to P. acnes. They produced more of an immune system factor thought to lower defenses against microorganisms called interleukin 10 when exposed to S. aureus (Cytokine, 2013).
But the small size of this study and the use of chocolate containing fats and sugars, which vary with different chocolates and could be the ingredients responsible, mean that these preliminary results should be taken with a grain of salt. In addition, this study looked at how chocolate affected the immune system in a way that might lower its defenses against acne bacteria, but not necessarily to what extent that affects acne.
Research Showing Chocolate Affects Acne
There is research about pure chocolate and acne, but the studies are small and have only been done on men.
In 2011, Samantha Block, a medical student at the University of Miami Miller School of Evidence, did a small study showing a positive correlation between chocolate and acne (Medscape Today). Instead of using bars with sugar and milk that might affect the studies outcome, Block gave her 10 male participants with a history of acne six ounces of Ghirardelli 100% cocoa bars and told them to maintain a regular diet. The results showed a link between chocolate consumption and acne. Subjects also experienced headaches, nausea, gastrointestinal distress, and diarrhea (Journal of the American Academy of Dermatology, 2011).
Dermatologist F. W. Danby, M.D. suggested that this might be the result of theobromine, a stimulant that’s been shown to increase levels of sugar in the blood and basal metabolic rate might be at fault (Chocolate in Health and Nutrition, 2013). This brings a whole host of questions, which he points out, about what specifically in cocoa could cause acne and whether some brands have more of it than others.
Another of Block’s studies, which isn’t published yet, was a double-blind study where the 14 male participants with a history of acne either received a capsule filled with gelatin or one filled with 100% cocoa. Researchers found that acne increases were proportionate to the amount of chocolate eaten.
With so few quality studies and so many possibilities, the answer to whether chocolate affects acne is unresolved. The difficult part of determining what sort of effect diet has on a person is that foods don’t affect everyone the same way. All of these studies are small and many lack controls. They also use different kinds of chocolate with different proportions of cocoa and other ingredients, so it’s difficult to compare them. Many of the results are preliminary, meaning there are a lot of possible factors to explain their results and a lot of questions that future studies will look at. Few of these studies look at the effects that chocolate has on women’s acne, and subsequently don’t look at whether chocolate affects the sexes differently.
We don’t know to what extent diet affects acne compared to other factors like genetics, environment, and stress; but many researchers feel that they’re connected. We also don’t know how much more sensitive to certain foods or diets one group might be than another. So, for now, there’s no definitive answer on acne and chocolate. Hopefully future studies will illuminate how this sweet treat might affect skin issues, and we’ll be sure to keep you updated!