Does chocolate cause spots on the face?

The effect of chocolate on the exacerbation of acne has been widely debated in the literature. The scientific responses to this issue are not yet unanimous; there are conflicting pieces of evidence. Some studies have not demonstrated a specific correlation between chocolate consumption and acne, suggesting that it is not the chocolate itself that causes spots. 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 renowned study conducted by J.E. FULTON in 1969, which is frequently 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.

Subsequently, another study assessed the effect of fifteen Jelly Beans sweets 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 the formation of spots. 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 consumed 340 grams of 100% chocolate in one go, 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 start 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.

A further research study from 2016 also aimed to investigate 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 quantity of capsules filled with either 100% unsweetened cocoa powder, hydrolysed gelatine, or a combination of the two in varying proportions. The result was the same, an increase in the number of 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 the exacerbation of acne. 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 keratinisation of the epithelium, leading to the formation of comedones.