- 1969: No Relationship Between Chocolate and Acne Formation
- Since 2011: Inconclusive Relationship Between Chocolate and Acne Formation
- Conclusion from the Studies
- Why Chocolate and Acne Could Hypothetically Be Related
- The Bottom Line
The role of chocolate in acne has been controversial for decades. Chocolate is typically made with milk, cocoa butter, and sugar, all of which might hypothetically increase acne lesions. However, the science is still not complete in any of these areas.
On the flip side, chocolate contains flavonoids, and this might hypothetically help decrease the severity of acne.
The best way to determine whether chocolate affects acne is to look at the scientific studies. One initial and flawed study in 1969 found no connection, and the conclusion that no connection existed continued until 2011, when research resumed and several newer studies began finding a weak connection.
Let's start by looking at the initial 1969 study that got the whole world saying chocolate does not affect acne, and why we should not give as much credibility to its findings as we thought.
1969: No Relationship Between Chocolate and Acne Formation
In 1969, a study published in the Journal of the American Medical Association first explored the relationship between chocolate and acne.
The study included 35 young adult male prisoner volunteers in addition to 30 male and female adolescents. The participants were given either a chocolate bar or a placebo bar. The placebo bar was a bar that looked and tasted like chocolate but contained no chocolate. At the end of the study, the researchers concluded that chocolate had no effect on acne severity.1
This study took on a life of its own, with other researchers often citing it in other scientific literature, and its conclusions remained unchallenged for decades. However, in 2011, a closer inspection of the 1969 study's design and methods discovered many worrying limitations, including:
- Differences in gender composition between the group that received the chocolate bar and the group that received the placebo bar.
- Excluding the age of participants. Neither the “young adult male prisoners” nor the “adolescent boys and girls” mean age was stated.
- Variations in menstrual cycle, weight, stress, lifestyle, and the use of caffeine, tobacco, or medications amongst participants, all of which may affect acne severity, were not mentioned.
- Differences in composition of the chocolate bars and the placebo bars. The placebo bars contained more hydrogenated fats.
- The short duration of the study (4 weeks).
- Not including a description of the statistical methods.
- A conflict of interest. The study was sponsored by the Chocolate Manufacturers Association of the USA.2
Due to the design flaws of the study, it was concluded that its conclusion that chocolate did not affect acne was unreliable.
Since 2011: Inconclusive Relationship Between Chocolate and Acne Formation
Beginning in 2011, scientists once again began taking a fresh look into chocolate and whether or not it has any affect on acne, and began finding a link. However, as you read, remember that studying the effect of diet on any disease is difficult, and so conclusions are still tentative.
In 2011, a study published in the Journal of the American Academy of Dermatology found that 100% chocolate increased the number of acne lesions in a group of 10 men between the ages of 18 and 35.3
However, this study also had limitations, including:
- No control group.
- Small sample size (only 10 people)
- Exclusion of females.
- Limited follow-up time.
Variables such as diet (sugar and calorie intake), weight, or smoking status, all of which may influence the development of acne, were not mentioned.3
In 2014, another study was performed that expanded on the 2011 study. Thirteen male subjects with mild acne took either capsules filled with 100% cocoa, capsules filled with only hydrolyzed gelatin (placebo), or a combination of both. The results showed an increase in acne on day 4 and day 7. The authors concluded that there was a correlation between the consumption of chocolate and an increase in acne lesions observed during their study.4
However, there were considerable limitations to this study, including:
- Small sample size (only 13 people).
- Exclusion of females.
- Variables such as he amount of dairy or sugar consumed, were not mentioned.4
- Very short one-week study.
- Acne lesions can take 2-6 weeks to form.
Therefore, it is unclear whether other factors or the consumption of chocolate played a role in the results observed.
In 2015, a survey of 2,266 French adolescents and young adults, of which 1,375 participants had acne and 891 participants had no acne, found that the consumption of chocolate and sweets was associated with participants who reported having acne.5
However, once again, this study had limitations, including:
- Variables such as sugar, milk, and chocolate were not separately investigated.
- Self-reported data.
The study relied on survey answers from participants, which is not the most robust method of gathering data.5
In 2016, a study of 25 men from ages 18 to 30 years old found that 99% dark chocolate increased existing acne.6After a 4-week period of abstaining from any food containing chocolate, the researchers asked participants to consume 25 grams of 99% dark chocolate daily for an additional 4 weeks. The study stated that the participants’ diets did not change significantly throughout the study period, and concluded that the dark chocolate caused the increase in acne.6
However, limitations to the study included:
- No placebo group.
- A small sample size (only 25 people).
- The exclusion of females.
Lifestyle variables such as the participants’ consumption of alcohol, dairy, and sugar, were not controlled during the study.
In 2016, a study found that the consumption of milk chocolate appeared to increase acne lesions among 54 college students with an average age of 21.4 years.7In this study, 54 students were divided into two groups. One group was given a 1.55-ounce Hershey’s milk chocolate bar, and the other group was given 15 Jelly Belly jellybeans. Both types of candy had the same glycemic load. Neither group was allowed to eat chocolate other than the chocolate provided during the study.
Researchers assessed the number of acne lesions 48 hours after participants ate the candy. Then, four weeks after the first trial, the type of candy each group consumed was switched, and acne lesions were again assessed 48 hours later.
In both trials, the researchers observed an increase in acne lesions among participants consuming milk chocolate compared to those consuming jellybeans.7
However, as with all of the other studies, there were several limitations to this study, including:
- A small sample size (only 54 people).
- The variable of dairy, which is present in milk chocolate, was not controlled for. Some weak evidence shows may aggravate acne, and researchers did not take dairy under consideration.
- Extremely short study. Since acne can take 2 to 6 weeks to form, observing acne formation after 48 hours may not be enough time to determine whether chocolate caused the observed increases.6
Conclusion from the Studies
Overall, after 2011 we can see evidence begin to mount that chocolate might in fact lead to increased acne symptoms. However, every study had serious limitations. Therefore, while it is interesting that all five studies after 2011 show a correlation between chocolate and acne, we still cannot state definitively that there is a link.
Why Chocolate and Acne Could Hypothetically Be Related
If we look at the components of chocolate separately, some might hypothetically increase acne, while some might decrease, or have no effect on acne.
Components that may increase acne:
- Chocolate has been shown to stimulate the effects of inflammatory molecules called cytokines. Acne is an inflammatory disease, so any increase in inflammation could make acne worse.8
- The cocoa butter in dark chocolate contains oleic acid, which some studies indicate may alter the formation of skin cells around pores, resulting in the formation of clogged pores.6
Components that may decrease acne, or have no effect:
- Chocolate contains a large number of flavonoids, which have antioxidant properties.6Antioxidants have shown beneficial effects on acne.10
- Additionally, flavonoids might improve the body’s response to insulin, which may be linked to decreased acne.11
A 2013 study showed that chocolate did not increase amounts of acne bacteria. Acne is in part a bacterial disease, and this one study points toward chocolate not being able to increase bacteria.8
The Bottom Line
Research on the effects of chocolate on acne is conflicting. While the bulk of studies since 2011 show a correlation between chocolate consumption and acne, all of these studies have limitations, and other studies on the components of acne have shown that some components of chocolate may increase acne, while others may decrease it, or have no effect. Until more research is done, we cannot say for certain what effect reducing or eliminating your chocolate intake will have on your acne. In the meantime, a proper treatment regimen can greatly improve the health of your skin and reduce acne lesions.