Bad news for lovers of acne-prone chocolate: Scientists have discovered that consuming pure chocolate for several days can exacerbate facial acne in people with a history of this type of skin problem. These data were presented at the 69th Annual Congress of the American Academy of Dermatology.

In previous studies on the effect of diet on the evolution of acne, it has not been shown that the consumption of chocolates, which in addition to chocolate contain other ingredients (milk, sugar and nuts) , leads to an exacerbation of acne. However, to date, no study has been conducted to assess the effect of whole chocolate, made from 100% cocoa, on the development of acne.

The study looked at 10 healthy men aged 18 to 35 who had a history of facial acne. Patients at the time of enrollment in the study had at least 1, but not more than 4 inflammatory foci (comedones and papules without pustules). The study was not allowed to use over-the-counter or prescription drugs to treat acne.

This study was limited to the inclusion of single men, as women may be affected by interfering factors, namely changes in hormone levels during the menstrual cycle, which could affect the results of the study.

Study participants consumed 6 ounces (170 g) of Ghirardelli chocolate with a glass of water. The reason why Ghirardelli chocolate was chosen for the study is very simple - no other manufacturer makes 100% cocoa chocolate.

Participants were asked to follow their normal diet for 1 week. The number of lesions on the face was evaluated during the initial visit, as well as on days 4 and 7 of the study.

The researchers noted a statistically significant increase in the number of all types of lesions (blackheads, papules and pustules) on day 4 (p = 0.031) and 7 (p = 0.05) compared to the initial data. There was also a tendency to increase the average number of non-inflammatory comedones on day 4 (p = 0.058) and 7 (0.067). There were no statistically significant differences in the number of inflammatory foci (papules and pustules) during a period of the study.

In this study, a strong correlation was found between the amount of chocolate consumed and the number of acne lesions developed (r = 0.510 on day 4 and 0.608 on day 7). Study participants also reported headaches, nausea, gastrointestinal upset, vomiting, and diarrhea with such a "chocolate" diet.

The possible mechanism of this phenomenon is as follows: chocolate contains theobromines which, in addition to worsening acne, can also cause headaches.

Thus, this study demonstrated that 100% chocolate causes an exacerbation of acne in sensitive individuals. The researchers plan to continue this work and conduct a randomized, placebo-controlled trial.