Some patients insist it does, and now there is support for this claim!
A recent study found that eating 100% pure Ghiradelli chocolate significantly worsened acne. Dermatologists at the University of Miami fed 10 male subjects aged 18 – 35 unsweetened 100% pure cacao chocolate at a single setting. One week later, the number of acne lesions they had increased over 600%! The average participant had 2.7 lesions at baseline and 18.2 on day seven. The investigators also found that the more chocolate a participant ate, the worse his acne became.
Previous studies looking at the relationship between chocolate and acne have failed to find an association. The investigators suspect this may be because those studies were not done with 100% pure chocolate. They were done with chocolate candy which contains many other ingredients.
Is this study proof that chocolate causes acne? No. However, it does suggest an association, and the investigators are currently performing a more rigorous study to prove a link. Until then, enjoy chocolate in moderation, and if you do have acne, there are many treatments available including laser acne treatments.