In the previous Diet & Acne JAAD review, Bowe et al suggested
that high glycemic load (HGL) diets might exacerbate
acne. Recent studies appear to lend support to this conclusion,
implicating high glycemic index foods even further in
the exacerbation of acne. To place these recent findings into
context, it is necessary to briefly review two key studies that
were described in the initial Diet and Acne review. In a crosssectional
study, Cordain et al noted an absence of acne cases
in non-Westernized societies. After comparing the differences
in dietary habits of these societies with the typical Western
diet, these authors chose to focus on the glycemic load of
the diets, concluding that diet-induced hyperinsulinemia was
to blame for acne in Westernized societies.12 Bowe et al further
identified the Smith et al studies to be ground breaking
studies in elucidating the relationship between carbohydrate
intake and acne severity. In a series of three randomized control
trials and a nonrandomized clinical trial, Smith et al tested
the hypothesis that diet-induced hyperinsulinemia could result
in IGF-1 and androgen imbalances, causing changes in sebum composition and resulting in an increase in acne in
male patients.13-16 Low GI foods, on the other hand, resulted
in weight loss and ultimate improvements in acne. However,
as noted in Bowe et al, there were a few limitations to these
studies, including the use of only adolescent males and failure
to account for weight loss as a possible confounding variable.
Such limitations brought into question whether it was a decrease
in GI or a decrease in BMI that led to improvements
in acne, and whether such findings could be extrapolated to
female patients as well.10 We follow with a summary of more
recent studies exploring the link between carbohydrates and
acne, starting with the most rigorous of study designs and
ending with studies that suffer from serious design flaws. Although
not chronological, the authors felt this approach led to
a more meaningful analysis of the available data.
Since the Cordain and Smith studies, the strongest evidence to
implicate high GI diets in acne has been a randomized control trial
conducted by Kwon et al, which showed that subjects adhering to
