Table 2.

Selected studies on the effect of chocolate on the pathogenesis of acne vulgaris.

Research	Year	Methodology	Key Result	References
Caperton et al.	2014	14 men aged 18 to 35 years with a history of acne vulgaris were assigned to swallow capsules filled with unsweetened 100% cocoa, hydrolysed gelatine powder, or a combination of both. Acne changes were assessed at the start of the study, on day four, and on day seven of the study.	There was a positive Pearson correlation coefficient of low strength between the amount of chocolate consumed by each participant and the number of lesions developed in each patient between baseline and day 4, while there was a positive correlation of medium strength between baseline and day 7.	[81]
Vongraviopap S. et al.	2015	25 acne-prone men consumed 25 g of dark chocolate (99% cocoa) daily for four weeks. The severity of acne lesions at the start of the study, and after two and four weeks of the study were assessed.	Statistically significant changes in acne scores and the number of blackheads and inflammatory papules were detected after 2 weeks. After 4 weeks, changes remained statistically significant compared to baseline values.	[84]
Chalyk N. et al.	2018	33 men (17 young men and 16 middle-aged men) consumed 10 g per day of dark chocolate (70% cocoa) for 4 weeks. Morphological characteristics of residual skin surface components (RSSCs) were assessed before the introduction of chocolate into the diet and after consumption for 4 weeks. Samples were assessed by staining with haematoxylin and eosin, Oil Red O, and crystal violet solution (Gram staining).	Chocolate consumption increased corneocyte exfoliation in both age groups, but the increase was statistically significant in the young male group. A significant increase in the presence of Gram-positive micro-organisms on the skin surface was observed.	[72]
Suppiah T. et al.	2018	The severity of acne lesions was assessed and a questionnaire interview on eating habits was conducted among 57 subjects with acne vulgaris and 57 controls. All subjects were 14 years of age or older.	Chocolate consumption was significantly higher among sick people with acne vulgaris compared to controls.	[82]
Karadağ A. et al.	2019	The study involved 3826 patients with acne vulgaris and 759 control patients. A dermatologist assessed the severity of the skin lesions and a questionnaire evaluating the subjects’ dietary habits was administered.	A positive correlation was found between chocolate consumption and the severity of acne lesions.	[83]