Here are couple of new studies on acne that show the
beneficial results of a low glycemic diet that Dr. Cordaine
pointed out to me that 'a similar study could be easily
conducted with rosacea patient' :

Smith R, Mann N, Braue A, Varigos G. The effect of a low glycemic load, high
protein diet
on hormonal markers of acne. Asia Pac J Clin Nutr. 2005;14 Suppl:S43.

Background - Acne vulgaris is a common endocrine condition affecting adolescents
in
Western civilizations. Acne typically manifests during puberty when there is a
transient
decrease in insulin sensitivity. It has been suggested that high glycemic
nutrition during
puberty induces hyperinsulinemia which increases the bioavailability of
androgens and
certain growth factors. These changes may induce follicular epithelial growth
and
increased sebum production - two factors responsible for acne proliferation.
Objective -
To determine the effect of a low glycemic load diet, comprised of high levels of
protein
and low glycemic index (GI) foods, on hormonal makers of acne vulgaris. Design -
Male
acne sufferers [n=43, age=18.3+/-0.4 (mean +/- SEM)] were randomly assigned to
either
the dietary intervention (n=23) or control groups (n=20). The intervention diet
consisted
of 25% energy from protein and 45% energy from low glycemic index carbohydrates.
The
control group received no information about diet nor were they given dietary
instruction.
Venous blood was collected at baseline and 12-weeks for an assessment of
testosterone,
sex hormone binding globulin (SHBG), free androgen index (FAI),
dehydroepiandrosterone
- sulfate (DHEA-S), insulin-like growth factor (IGF)-I and IGF-binding proteins
-I and -3.
Outcomes - Dietary intervention resulted in a significant reduction in FAI (-9.1
+/- 4.5,
P<0.05) and DHEA-S (-0.72 +/- 0.33 umol/L, P<0.05) and an increase in IGFBP-1
(5.3
+/- 1.6 ng/mL, P<0.01). No significant changes were observed in levels of IGF-I,
IGFBP-3,
testosterone or SHBG following dietary intervention. The control group showed no
change
in any of the blood parameters measured. Conclusion - These data suggest that a
low
glycemic load diet may reduce androgenic activity (as indicated by a reduction
in FAI and
DHEA-S) and may oppose the growth promoting effects of IGF-I by increasing
levels of its
binding protein, IGFBP-I. This implies that a low glycemic load diet may reduce
hormonal
influences involved in acne pathogenesis.

Smith R, Mann N, Braue A, Varigos G. Low glycemic load, high protein diet
lessens facial
acne severity. Asia Pac J Clin Nutr. 2005;14 Suppl:S97.

Background - Acne vulgaris is a multi-factorial skin disorder which affects the
85-100% of
the adolescent population in Western civilizations. Despite its high prevalence
in the West,
acne prevalence is extremely low or rare in non-westernized societies. It has
been
proposed that refined, high glycemic foods common in Western societies may
accentuate
underlying causal factors responsible for its proliferation. Objective - To
determine
whether a low glycemic load diet, comprised of high levels of protein and low GI
foods,
can alleviate the severity of acne symptoms in young males. Design - Male acne
sufferers
[n=43, age=18.3 +/- 0.4 (mean +/- SEM)] were randomly assigned to either the
dietary
intervention (n=23) or control groups (n=20). The intervention diet consisted of
25%
energy from protein and 45% energy from low glycemic index carbohydrates. The
control
group received no information about diet nor were they given dietary
instruction. The
efficacy of dietary treatment versus control was clinically assessed by a
dermatologist
using a modified Cunliffe-Leeds acne scale. The dermatologist assessed facial
acne by
means of lesion counts and was blinded to the subject's group. Outcomes -
Dietary
intervention resulted in a reduction in total lesion counts (-23.1 +/- 4.0
lesions, P
<0.001) and inflammatory counts (-16.2 +/- 3.0 lesions, P <0.001). The control
group
also showed a reduction in total lesion counts (-12.0 +/- 3.5 lesions, P <0.01)
and
inflammatory counts (-7.4 +/- 2.5 lesions, P <0.05). However, between group
analyses
showed that the reduction was significantly greater in the intervention group
for total
counts (P <0.05) and inflammatory counts (P <0.05). Conclusion - These data
indicate
that a low glycemic load diet, comprised of high levels of protein and low GI
foods,
significantly decreased the mean number of facial acne lesions, therefore
alleviating the
severity of acne symptoms. However, the multi-factorial nature of this condition
is
reflected in the fact that the control group also showed a decrease over time,
thereby
suggesting that other factors are at play.