A pilot study to determine the short-term effects of a low glycemic load diet on hormonal markers of acne: a nonrandomized, parallel, controlled feeding trial.

Observational evidence suggests that dietary glycemic load may be one environmental factor contributing to the variation in acne prevalence worldwide. To investigate the effect of a low glycemic load (LGL) diet on endocrine aspects of acne vulgaris, 12 male acne sufferers (17.0 +/- 0.4 years) completed a parallel, controlled feeding trial involving a 7-day admission to a housing facility. Subjects consumed either an LGL diet (n = 7; 25% energy from protein and 45% from carbohydrates) or a high glycemic load (HGL) diet (n = 5; 15% energy from protein, 55% energy from carbohydrate). Study outcomes included changes in the homeostasis model assessment of insulin resistance (HOMA-IR), sex hormone binding globulin (SHBG), free androgen index (FAI), insulin-like growth factor-I (IGF-I), and its binding proteins (IGFBP-I and IGFBP-3). Changes in HOMA-IR were significantly different between groups at day 7 (-0.57 for LGL vs. 0.14 for HGL, p = 0.03). SHBG levels decreased significantly from baseline in the HGL group (p = 0.03), while IGFBP-I and IGFBP-3 significantly increased (p = 0.03 and 0.03, respectively) in the LGL group. These results suggest that increases in dietary glycemic load may augment the biological activity of sex hormones and IGF-I, suggesting that these diets may aggravate potential factors involved in acne development.

A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial.

BACKGROUND: Although the pathogenesis of acne is currently unknown, recent epidemiologic studies of non-Westernized populations suggest that dietary factors, including the glycemic load, may be involved. OBJECTIVE: The objective was to determine whether a low-glycemic-load diet improves acne lesion counts in young males. DESIGN: Forty-three male acne patients aged 15-25 y were recruited for a 12-wk, parallel design, dietary intervention incorporating investigator-blinded dermatology assessments. The experimental treatment was a low-glycemic-load diet composed of 25% energy from protein and 45% from low-glycemic-index carbohydrates. In contrast, the control situation emphasized carbohydrate-dense foods without reference to the glycemic index. Acne lesion counts and severity were assessed during monthly visits, and insulin sensitivity (using the homeostasis model assessment) was measured at baseline and 12 wk. RESULTS: At 12 wk, mean (+/-SEM) total lesion counts had decreased more (P=0.03) in the low-glycemic-load group (-23.5 +/- 3.9) than in the control group (-12.0 +/- 3.5). The experimental diet also resulted in a greater reduction in weight (-2.9 +/- 0.8 compared with 0.5 +/- 0.3 kg; P<0.001) and body mass index (in kg/m(2); -0.92 +/- 0.25 compared with 0.01 +/- 0.11; P=0.001) and a greater improvement in insulin sensitivity (-0.22 +/- 0.12 compared with 0.47 +/- 0.31; P=0.026) than did the control diet. CONCLUSION: The improvement in acne and insulin sensitivity after a low-glycemic-load diet suggests that nutrition-related lifestyle factors may play a role in the pathogenesis of acne. However, further studies are needed to isolate the independent effects of weight loss and dietary intervention and to further elucidate the underlying pathophysiologic mechanisms.

The effect of a high-protein, low glycemic-load diet versus a conventional, high glycemic-load diet on biochemical parameters associated with acne vulgaris: a randomized, investigator-masked, controlled trial.

BACKGROUND: No previous study has sought to examine the influence of dietary composition on acne vulgaris. OBJECTIVE: We sought to compare the effect of an experimental low glycemic-load diet with a conventional high glycemic-load diet on clinical and endocrine aspects of acne vulgaris. METHODS: A total of 43 male patients with acne completed a 12-week, parallel, dietary intervention study with investigator-masked dermatology assessments. Primary outcomes measures were changes in lesion counts, sex hormone binding globulin, free androgen index, insulin-like growth factor-I, and insulin-like growth factor binding proteins. RESULTS: At 12 weeks, total lesion counts had decreased more in the experimental group (-21.9 [95% confidence interval, -26.8 to -19.0]) compared with the control group (-13.8 [-19.1 to -8.5], P = .01). The experimental diet also reduced weight (P = .001), reduced the free androgen index (P = .04), and increased insulin-like growth factor binding protein-1 (P = .001) when compared with a high glycemic-load diet. LIMITATIONS: We could not preclude the role of weight loss in the overall treatment effect. CONCLUSION: This suggests nutrition-related lifestyle factors play a role in acne pathogenesis. However, these preliminary findings should be confirmed by similar studies.

In vivo safety assessment of two Bifidobacterium longum strains.

Bifidobacteria are important members of the intestinal microbiota and are considered to contribute to maintaining health. However, the level of bifidobacteria colonising the intestine of elderly subjects tends to be lower than in younger adults. Therefore, two Bifidobacterium longum strains, isolated from healthy elderly, were chosen for supplementation of the endogenous Bifidobacterium microbiota in the elderly. Bifidobacteria are generally regarded safe for human consumption. However, since the strains are intended for consumption by the elderly, whom may be more prone to disease, it is important to ascertain their safety. For this purpose, the strains were given to healthy adult volunteers. No side effects were reported and no undesirable changes observed in the immune parameters measured. Based on this study it appears that the two strains are well tolerated by human subjects and there are no reservations about their food use.