Does chocolate cause pimples on the face?

The effect of chocolate on the exacerbation of acne has been debated numerous times in literature. The scientific responses on this subject are not yet unanimous; there is conflicting evidence. Some studies have not demonstrated a particular correlation between chocolate consumption and acne, and that it is not the chocolate itself that causes pimples. The analyses suggest that it is the additive ingredients (milk, sugars, etc...) contained in the chocolate that contribute to the worsening of acne.

This general consensus is largely based on a famous study conducted by J.E. FULTON in 1969, which is often cited in literature, establishing that there is no link between chocolate consumption and acne. In this study, he evaluated the worsening of acne over 11 weeks in a group of subjects already presenting with acne lesions (n = 65) who were required to consume either a chocolate bar or a placebo bar rich in fats and sugars, but without chocolate, each day. The study led to the conclusion that chocolate consumption does not influence the occurrence of new acne outbreaks more than its substitute. However, this study presents several erroneous elements: the short duration of the experiment, an inappropriate control that contained as much sugar and fat as the chocolate bar, the method of counting skin lesions, as well as the absence of data on the severity of the observed lesions.

Later, another study evaluated the effect of fifteen Jelly Beans candies and a chocolate bar on the skin of fifty-six students. It concluded that the ingestion of chocolate does not contribute to the emergence of new skin lesions. However, this study had a flaw: the distributed chocolate bar contained sugars and milk, foods that exacerbate acne. Thus, the link between chocolate and the development of new acne lesions was replaced by the theory that a high glycemic load can affect the formation of acne. Therefore, these results are not robust enough to draw any conclusions.

However, this dogma was later challenged. Until now, there were no clinical studies regarding the direct effect of 100% cocoa on pimple formation. Yet, recent studies support the idea that the worsening of acne may be linked to chocolate consumption. In one study, male volunteers with a history of acne ingested 340 grams of 100% chocolate in one sitting, while maintaining a normal diet for a week. After 4 and 7 days, a statistically significant increase in the average number of total acne lesions (papules, nodules, comedones, pustules) was observed compared to the beginning of the study. However, the design of this study has several limitations: small sample size (n = 10), absence of a control group, and the study duration being too short.

Another research study from 2016 also aimed to examine the effects of dark chocolate on the exacerbation of existing acne. Twenty-five men (thereby excluding the effects of female hormones and premenstrual flare-ups) with acne-prone skin consumed daily chocolate with 99% cocoa, thus eliminating the effects of sugars and milk. After four weeks of chocolate consumption, the number of acne lesions significantly increased, particularly the number of comedones and inflammatory papules.

A similar experiment was conducted in 2014 on men with a history of acne. They were required to ingest a significant amount of capsules filled with either 100% unsweetened cocoa powder, hydrolyzed gelatin, or a combination of the two in varying proportions. The result was the same, an increase in both inflammatory and non-inflammatory lesions was observed. It would thus appear that in male individuals prone to acne, the consumption of chocolate is correlated with an increase in acne exacerbation. However, this study was conducted on a smaller number of subjects (n = 14).

However, these studies have limitations: they only focus on individuals who already have an acne problem. What about those who are not prone to it? Moreover, this exacerbation of acne by chocolate is not certain due to the small number of studies. Indeed, cocoa contains a large amount of flavonoids known for their antioxidant and anti-inflammatory virtues. Dark chocolate also contains cocoa butter, which includes, among other things, 33% monounsaturated oleic acid and 33% stearic acid. But it has been shown that oleic acid alters the keratinization of the epithelium, which leads to the formation of comedones.