Double-blind,Placebo-controlled Study Assessing the Effect of Chocolate Consumption in Subjects with a History of Acne Vulgaris

Objective: To assess the effect of chocolate on acne exacerbation in males between the ages of 18 and 35 with a history of acne vulgaris. Design: Double-blind, placebo-controlled, randomized, controlled trial. Setting: Single-site, outpatient, research, clinical facility at an academic research institution. Participants: Fourteen men between the ages of 18 and 35 were assigned to swallow capsules filled with either unsweetened 100-percent cocoa, hydrolyzed gelatin powder, or a combination of the two, at baseline. Measurements: Lesions were assessed and photographs were taken at baseline, Day 4, and Day 7. Results: Of the 14 subjects, 13 completed this Institutional Review Board approved study. A statistically significant increase in the mean number of total acneiform lesions (comedones, papules, pustules, nodules) was detected on both Day 4 (p=0.006) and Day 7 (p=0.043) compared to baseline. A small-strength positive Pearson’s correlation coefficient existed between the amount of chocolate each subject consumed and the number of lesions each subject developed between baseline and Day 4 (r=0.250), while a medium-strength positive correlation existed between baseline and Day 7 (r=0.314). No serious adverse events occurred. Conclusion: It appears that in acne-prone, male individuals, the consumption of chocolate correlates to an increase in the exacerbation of acne.The effect that chocolate has on acne has been debated in the literature. Although it has been hypothesized that several factors, including body mass index (BMI), hormonal levels, glucose levels, emotional stress, and glycemic index, may have an effect on acne, the role of the diet in the generation and/or worsening of acne remains controversial.1 In 2002, Cordain et al2 demonstrated that Westerners have a higher percentage of the population suffering from acne vulgaris than two non-Westernized populations, including Kitavan Islanders of Papua New Guinea and Aché hunter-gatherers of Paraguay.2 Despite this, few studies have evaluated the effects of chocolate on acne.One study of note was conducted in 1969 by Fulton et al.3 Sixty five subjects were assigned to consume either a chocolate bar that contained 10 times the amount of bittersweet chocolate of a normal 45g chocolate bar or a chocolate-less placebo bar that contained 28 percent vegetable fat corresponding with the fat content in chocolate liqueur and cocoa butter. Both bars weighed between 112 and 114g, although the control bar had 592 more calories than the experimental bar. The results demonstrated no significant difference between the two groups, suggesting that chocolate had no effect on acne.3 However, Mackie and Mackie4 criticized the study for the ingredients in the placebo bar that attempted to mimic the lipid and sugar contents of the chocolate bar. In addition, they criticized that the xanthine content was not mentioned for either bar.4 Rasmussen5 criticized Fulton’s method for lesion quantification, as all types of lesions (comedones, papules, and pustules) were accounted equally, thus not assessing the severity of the acne.One other study that assessed the effect of chocolate on acne was conducted by Anderson. Twenty-seven medical students were administered six servings of 39g chocolate bars for seven days. Facial acneiform lesions were counted at baseline and then daily during the seven-day study. Although the methods used were not appropriately stated, the author did not observe a causal relationship between chocolate consumption and acne proliferation.6Review of the literature in 2009 showed that there were no studies assessing the effects of chocolate with 100-percent content of cocoa on acne. In turn, the authors’ study team felt that it was necessary to conduct a study assessing pure chocolate on acne. In a recent pilot study published in the Journal of the American Academy of Dermatology, Berman et al7 assessed the effect of 100-percent cocoa on the exacerbation of acne in men between the ages of 18 and 35 years. At baseline, the study team had 10 healthy male subjects consume up to six ounces of 100-percent chocolate (Ghirardelli baking bars). Lesions were counted, assessed, and documented appropriately at baseline, Day 4, and Day 7. Statistical significance was achieved when the total mean number of acneiform lesions, including comedones, papules, and pustules, on Days 4 and 7 were compared to baseline (P=0.031 and 0.050 for Days 4 and 7, respectively). Additionally, strong positive Pearson’s correlations were calculated analyzing the amount of chocolate each subject consumed and the number of lesions subjects developed on Days 4 (r=0.510) and 7 (r=0.608). This dose-dependent relationship that was found suggested that chocolate did exacerbate acne in men with a history of acne vulgaris.7 However, this study did have limitations as only 10 subjects were included, and the study was not double-blinded nor placebo controlled. Therefore, the authors decided to expand on this pilot study and created an Institutional Review Board (IRB)-approved protocol to analyze the effect of chocolate’s exacerbation on acne in a double-blind, placebo-controlled study.