Acne: The Role of Medical Nutrition Therapy

The effect of the ketogenic diet on Acne: Could it be a therapeutic tool?

Acne is a chronic inflammatory disease of the pilosebaceous unit resulting from androgen-induced increased sebum production, altered keratinization, inflammation, and bacterial colonization of the hair follicles of the face, neck, chest and back by Propionibacterium acnes. Overall, inflammation and immune responses are strongly implicated in the pathogenesis of acne. Although early colonization with Propionibacterium acnes and family history may play an important role in the disease, it remains unclear exactly what triggers acne and how treatment affects disease progression. The influence of diet on acne disease is a growing research topic, yet few studies have examined the effects of diet on the development and clinical severity of acne disease, and the results have often been contradictory. Interestingly, very low-calorie ketogenic diet (VLCKD) has been associated with both significant reductions in body weight and inflammatory status through the production of ketone bodies and thus it has been expected to reduce the exacerbation of clinical manifestations or even block the trigger of acne disease. Given the paucity of studies regarding the implementation of VLCKD in the management of acne, this review aims to provide evidence from the available scientific literature to support the speculative use of VLCKD in the treatment of acne.

Stress induced production of plant secondary metabolites in vegetables: Functional approach for designing next generation super foods

Plant secondary metabolites are vital for human health leading to the gain the access to natural products. The quality of crops is the result of the interaction of different biotic and abiotic factors. Abiotic stresses during plant growth may reduce the crop performance and quality of the produce. However, abiotic stresses can result in numerous physiological, biochemical, and molecular responses in plants, aiming to deal with these conditions. Abiotic stresses are also elicitors of the biosynthesis of plant secondary metabolites in plants which possess plant defense mechanisms as well as human health benefits such as anti-inflammatory, antioxidative properties etc. Plants either synthesize new compounds or alter the concentration of bioactive compounds. Due to increasing attention towards the production of bioactive compounds, the understanding of crop responses to abiotic stresses in relation to the biosynthesis of bioactive compounds is critical. Plants alter their metabolism at the genetic level in response to different abiotic stresses resulting the changes in secondary metabolite production. Transcriptional factors regulate genes responsible for secondary metabolite biosynthesis in several plants under stress conditions. Understanding the signaling pathways involved in the secondary metabolite biosynthesis has become easy with the use of molecular biology. Therefore, aim of writing the review is to focus on secondary metabolite production in vegetable crops, their health benefits and transcription regulation under various abiotic stresses.

Incretin serum level as a biomarker of insulin Resistance in acne vulgaris patients

OBJECTIVE

To investigate the relationship between serum Incretin and acne vulgaris (AV) and insulin resistance (IR), and to find the biological indicators of acne vulgaris with insulin resistance.

METHODS

60 patients diagnosed with acne vulgaris in the dermatology department of Zagazig University and 56 healthy people in the health examination center of this hospital were collected respectively as the control group; all the included people were drawn fasting blood to test serum Incretin, blood lipids, sex hormones and INS release test to explore the role of serum Incretin in acne vulgaris and insulin resistance.

RESULTS

The average level of Incretin in the acne group was lower than that in the control group, and the difference was statistically significant (t=7.189, P<0.001). The average level of Incretin in the acne group with insulin resistance was lower than that in the acne without insulin resistance group, the difference was statistically significant (t=22.328, P<0.001). In the acne group, the insulin resistance index decreased with the increase of Incretin level, and the two showed a negative correlation. (R = -0.711, P<0.001.( CONCLUSIONS: Patients with acne vulgaris are prone to have insulin resistance. Insulin resistance in patients with acne vulgaris is negatively correlated with Incretin. Serum Incretin may be expected to be a biomarker for diagnosing acne vulgaris patients with insulin resistance. The severity of acne vulgaris may have no obvious correlation with insulin resistance and serum incretin.

Association Between Diet and Acne Severity: A Cross-sectional Study in Thai Adolescents and Adults

The association between diet and acne is of growing concern. Every country has its own food culture; however, only a few studies have surveyed the influence of Asian cuisine on acne. This study investigated the association between acne severity and diet/lifestyle factors in 2,467 Thai adolescents and adults. Data were collected via a validated semi-quantitative food frequency questionnaire. In Thai adolescents and adults, the prevalence of mild acne was 52%, moderate acne 22%, and severe acne 8%. No acne was found in 18% of participants. The dietary factors associated with increased severity of acne were consumption of chocolate >100 g/week (adjusted odds ratio (aOR) 1.29; 95% CI 1.07–1.56), oily and fried food >3 times/week (aOR 1.84; 95% CI 1.07–3.16) and white rice (aOR 1.80; 95% CI 1.24–2.63). Conversely, the factors associated with decreased severity of acne were consumption of sugar-free milk-free tea (aOR 0.61; 95% CI 0.43–0.87) and vegetables (aOR 0.74; 95% CI 0.62–0.89).

Acne and diet: a review

Acne is one of the most frequent dermatological afflictions especially for people in their first 30 years of age. Several studies have shown that nutrition is one of the key factors involved in acne pathogenesis. Data show that a high glycemic index diet may be a trigger in acne pathogenesis, while patients with a low glycemic index diet have fewer acne lesions. Milk and chocolate are also involved in the exacerbation of acne. However, foods rich in omega-3 fatty acids suppress the production of inflammatory cytokines with therapeutic effect. Additionally, docosapentaenoic acid and γ-linolenic acid have demonstrated improved acne lesions. The aim of this review was to summarize current knowledge on the association between acne and diet with special attention to the most frequently discussed factors involved in its pathogenesis: milk, chocolate, omega-3 fatty acids, hyperglycemia, hyperinsulinism, and IGF-1.

Bioactive Compounds for Skin Health: A Review

Human skin is continually changing. The condition of the skin largely depends on the individual’s overall state of health. A balanced diet plays an important role in the proper functioning of the human body, including the skin. The present study draws attention to bioactive substances, i.e., vitamins, minerals, fatty acids, polyphenols, and carotenoids, with a particular focus on their effects on the condition of the skin. The aim of the study was to review the literature on the effects of bioactive substances on skin parameters such as elasticity, firmness, wrinkles, senile dryness, hydration and color, and to define their role in the process of skin ageing.

Effects of Diet on Acne and Its Response to Treatment

Our understanding of the pathogenesis of acne vulgaris is still evolving. It is known that multiple factors impact acne pathophysiology, including genetic, hormonal, inflammatory, and environmental influences. Because of its implications in many of these factors, diet has been a part of the acne discussion for decades. Several studies have evaluated the significance of the glycemic index of various foods and glycemic load in patients with acne, demonstrating individuals with acne who consume diets with a low glycemic load have reduced acne lesions compared with individuals on high glycemic load diets. Dairy has also been a focus of study regarding dietary influences on acne; whey proteins responsible for the insulinotropic effects of milk may contribute more to acne development than the actual fat or dairy content. Other studies have examined the effects of omega-3 fatty acid and γ-linoleic acid consumption in individuals with acne, showing individuals with acne benefit from diets consisting of fish and healthy oils, thereby increasing omega-3 and omega-6 fatty acid intake. Recent research into the effects of probiotic administration in individuals with acne present promising results; further study of the effects of probiotics on acne is needed to support the findings of these early studies. In this review, we discuss the current evidence regarding the diets of US patients with acne and how they may impact acne and acne treatment.

The relationship among androgens, insulin resistance and ghrelin polymorphisms in post-adolescent male patients with severe acne vulgaris

INTRODUCTION

Ghrelin has anti-inflammatory and immunomodulatory activities. Data about the role of ghrelin and ghrelin polymorphisms in the development of acne vulgaris in post-adolescent male patients are limited.

AIM

To evaluate the role of serum androgens, insulin resistance, ghrelin and ghrelin polymorphisms in severe acne vulgaris.

MATERIAL AND METHODS

Thirty-five post-adolescent male patients with a mean age of 28.0 ±5.4 years and 33 age-and BMI-matched controls were enrolled. Serum androgens, lipids, insulin sensitivity parameters and ghrelin levels were determined. The PCR method was used for GHRL polymorphisms (rs27647, rs696217 and rs34911341 genotypes).

RESULTS

Patients had similar anthropometric measures to controls, except a significantly higher WHR in patients (0.92 ±0.06 vs. 0.86 ±0.08, p < 0.05). Also, FPG, HOMA-IR values, lipid profile and serum androgen levels were similar. Interestingly, patients had significantly lower ghrelin levels than controls (4.5 ±5.8 vs. 101.2 ±86.5 pg/ml, p < 0.001). The frequencies of rs696217 and rs34911341 genotypes were similar whereas the distribution of rs27647 alleles was significantly different between the groups (p < 0.05). GA and GG genotypes of GHRL rs27647 polymorphism indicated an increased risk of developing acne vulgaris (OR = 11.156, 95% CI: 2.864-43.464, OR = 5.312, 95% CI: 1.269-22.244, respectively; p < 0.05). Patients with rs27647-AA polymorphism had significantly lower GAGS scores than other groups (AA genotype 6.7 ±14.1 vs. GA genotype 24.6 ±15.7 and GG genotype 19.4 ±17.9, p < 0.001). None of the polymorphisms had a significant effect on metabolic parameters, insulin sensitivity and serum ghrelin levels.

CONCLUSIONS

Decreased ghrelin levels and GA and GG genotypes of GHRL gene rs27647 polymorphism may have a role in the pathogenesis of acne vulgaris.

Integrated targeted serum metabolomic profile and its association with gender, age, disease severity, and pattern identification in acne

Background

Westernized diet and nutritional metabolism are important in acne pathogenesis, especially in adult patients. However, clinical and basic data are lacking. Pattern identification (PI) is a tool that results in a diagnostic conclusion based on a cluster of concurrent symptoms and signs in traditional medicine. Acne can be classified by PI. However, whether the metabolomic profile differs according to the PI of acne is unknown. Metabolomic data would help clarify the pathogenesis of acne.

Methods

We conducted a cross-sectional study involving 40 healthy controls and 60 subjects with acne. We evaluated androgens, serum lipids, essential amino acids, nonessential amino acids, other amino acids, and pro-inflammatory cytokines of all subjects and compared the metabolomic profiles between acne subjects and healthy controls, and in subgroups according to gender, age, severity, and PI.

Results

Dehydroepiandrosterone sulfate and serum fatty acids were significantly higher in female subjects, adolescents, and those with disharmony of the thoroughfare and conception vessels. The total essential and nonessential amino acids were significantly lower in the overall, female, adult, severe, and phlegm-stasis group. The latter group exhibited elevated serum levels of interleukin-1β and -6.

Conclusions

This is the first study to investigate serum lipids, amino acids, and cytokines in subjects with acne. We analyzed the differences between metabolomic profiles to determine the diagnostic value of PI. Prospective studies with more patients are needed to confirm the characteristics of each PI and lipidomic data will enrich knowledge concerning lipid mechanism.

Adolescents' self perceived acne-related beliefs: from myth to science

BACKGROUND

Acne vulgaris is recognized as the third most prevalent skin disease worldwide, with highest prevalence among adolescents. Beliefs and perceptions of adolescents about acne are incoherent in the literature.

OBJECTIVES

To assess the most frequently reported acne-related beliefs in adolescents in order to focus on misconceptions and develop proper recommendations.

METHODS

A cross-sectional community-based study on representative sample of 2516 schoolchildren was conducted in six randomly selected secondary schools in Belgrade, Serbia. Only schoolchildren with present or past acne history participated. Factors believed to aggravate or ameliorate acne were recorded and analyzed, and the comparisons between girls and boys were evaluated using Pearson's chi-squared test.

RESULTS

A total of 1452 schoolchildren with acne participated, aged 14-18 years, among them 801 (55.2%) girls and 651 (44.8%) boys. Boys significantly more frequently believed that sweating, exercise, and dairy foods aggravate acne, whereas girls significantly more frequently blamed emotional stress, sweets, fatty foods, sun, and lack of sleep. The top four amelioration factors were as follows: comedone extraction, healthy diet, sun exposure, and increased water consumption. Acne regression was more frequently perceived to be linked with cigarettes in boys, but with sun exposure and weight loss in girls.

STUDY LIMITATIONS

The narrow age span of adolescents (14-18 years) and exclusion of acne-free adolescents are limitations due to study design.

CONCLUSION

This survey is part of the first epidemiological study on a representative sample in the Western Balkan region. The significance of the most frequent acne-related beliefs is discussed and myths about acne are highlighted.

From pathogenesis of acne vulgaris to anti-acne agents

Acne vulgaris is a cutaneous chronic inflammatory disorder with complex pathogenesis. Four factors play vital roles in acne pathophysiology: hyperseborrhea and dysseborrhea, altered keratinization of the pilosebaceous duct, Cutibacterium acnes (C. acnes) and inflammation. The main hormones responsible for the development of acne vulgaris include androgens, insulin and insulin-like growth factor-1. Other factors involved in this process are corticotropin-releasing hormone, α-melanocyte-stimulating hormone and substance P. Wnt/β-catenin signaling pathway, phosphoinositide 3-kinase (PI3K)/Akt pathway, mitogen-activated protein kinase pathway, adenosine 5'-monophosphate-activated protein kinase pathway and nuclear factor kappa B pathway participate in the modulation of sebocyte, keratinocyte and inflammatory cell (e.g. lymphocytes, monocytes, macrophages, neutrophils) activity. Among all the triggers and pathways mentioned above, IGF-1-induced PI3K/Akt/Forkhead box protein O1/mammalian target of rapamycin (mTOR) C1 pathway is the most important signaling responsible for acne pathogenesis. Commonly used anti-acne agents include retinoids, benzoyl peroxide, antibiotics and hormonal agents (e.g. spironolactone, combination oral contraceptive and flutamide). New approaches including peroxisome proliferator-activated receptor γ modifier, melanocortin receptor antagonists, epigallocatechin-3-gallate, metformin, olumacostat glasaretil, stearoyl-CoA desaturase inhibitor omiganan pentahydrochloride, K_DPT, afamelanotide, apremilast and biologics have been developed as promising treatments for acne vulgaris. Although these anti-acne agents have various pharmacological effects against the diverse pathogenesis of acne, all of them have a synergistic mode of action, the attenuation of Akt/mTORC1 signaling and enhancement of p53 signal transduction. In addition to drug therapy, diet with no hyperglycemic carbohydrates, no milk and dairy products is also beneficial for treatment of acne.

Is Oral Omega-3 Effective in Reducing Mucocutaneous Side Effects of Isotretinoin in Patients with Acne Vulgaris?

Background. Acne vulgaris is an inflammatory disease of pilosebaceous units which may cause permanent dyspigmentation and/or scars if not treated. Isotretinoin is recommended in the treatment of recalcitrant or severe acne, but it is associated with common adverse effects that frequently result in patients incompliance and discontinuation of the drug. The present study was designed to assess the efficacy of oral omega-3 in decreasing the adverse effects of isotretinoin. Materials and Methods. In this randomized double-blind clinical trial, a total of 118 patients with moderate or severe acne were randomly divided into two (case and control) groups. The control group was treated with isotretinoin 0.5 mg/kg, and the case group was treated with the same dose of isotretinoin combined with oral omega-3 (1 g/day). The treatment was lasted for 16 weeks and mucocutaneous side effects of isotretinoin were recorded and compared between the two groups in weeks 4, 8, 12, and 16. Results. Cheilitis (at weeks 4, 8, and 12), xerosis, dryness of nose at all weeks, and dryness of eyes (at week 4) were less frequent in the group that received isotretinoin combined with oral omega-3 compared to the group that received isotretinoin alone. Conclusion. Administration of oral omega-3 in acne patients who are receiving isotretinoin decreases the mucocutaneous side effects of isotretinoin. This trial is registered with  IRCT201306238241N2.

A comparative study of biological and metabolic biomarkers between healthy individuals and patients with acne vulgaris: A cross-sectional study protocol

Acne is a multifactorial dermatosis, which is influenced not only by hormones but also by the biochemical relationship between them and the pilosebaceous unit. Inflammatory cytokines, chemokines, active oxygen, and zinc are known to be associated with the development of acne. Further, steroid metabolism is known as one of the important factors related to sebum secretion and comedone formation in acne. However, there is a lack of studies comparing these human biomarkers between healthy individuals and patients with acne. In particular, no study has investigated the relationship between human biomarkers and patterns of acne yet.The purpose of this study is to investigate diagnostic human biomarkers in acne by comparing the biological and metabolic biomarkers between healthy individuals and patients with acne and identify the relationship between human biomarkers and patterns of acne.This study is a protocol for a cross-sectional study. Forty healthy participants and 60 patients with acne will be recruited at 1 center. We will collect their blood samples and analyze the molecular biological and metabolic biomarkers (cytokines, chemokines, reactive oxygen species, corticotropin-releasing hormone, zinc, amino acid, 1-carbon metabolite, lipid metabolite, etc.). Further, we will administer questionnaires regarding their diet, sleep, stress, and other factors relating to acne and measure their skin elasticity.The study protocol was approved by the Institutional Review Board of Oriental Medical Hospital at Kyung Hee Medical Center (KOMCIRB-161118-HR-062). Written informed consent will be obtained from all the participants. The trial was registered in the Clinical Research Information Service, Republic of Korea: KCT0002212.This trial will provide evidence regarding diagnostic human biomarkers in acne and the relationship between the human biomarkers and patterns of acne.

Differences in Dietary Glycemic Load and Hormones in New York City Adults with No and Moderate/Severe Acne

BACKGROUND

Glycemic index (GI) and glycemic load (GL) may be implicated in acne pathogenesis.

OBJECTIVE

This cross-sectional study examined differences between GI/GL and biological factors associated with acne among adults with and without moderate/severe acne. Secondary objectives included examining differences between food-aggravated acne beliefs and acne-specific quality of life among adults with and without moderate/severe acne.

DESIGN

As part of a cross-sectional study, participants completed a 5-day food record; blood draw to measure biological factors associated with acne (ie, glucose, insulin, insulin-like growth factor-1, insulin-like growth factor binding protein-3, and sex hormone-binding globulin concentrations); body composition assessment; and questionnaire to evaluate food-aggravated acne beliefs and acne-specific quality of life. Food records were analyzed using Nutrition Data Services for Research.

PARTICIPANTS

Sixty-four participants (no acne, n=32; moderate/severe acne, n=32) from New York City, NY, were included in this study.

STATISTICAL ANALYSIS

Independent sample t tests and Mann-Whitney tests examined differences in anthropometric measurements, dietary intakes, biological factors associated with acne, insulin resistance, and acne-specific quality of life between acne groups. A χ² test for independence assessed differences in food-aggravated acne beliefs between acne groups.

RESULTS

Participants with moderate/severe acne consumed greater total carbohydrate (P=0.003), available carbohydrate (P<0.001), percent energy from carbohydrate (P<0.001), and GL (P<0.001) compared to participants without acne. Participants with moderate/severe acne had greater insulin (P=0.002) and insulin-like growth factor-1 (P=0.009) concentrations, greater insulin resistance (P=0.001), and lower sex hormone-binding globulin (P=0.015) concentrations compared to participants without acne. Although there were no differences between groups, 61% of participants reported food-influenced acne. Participants with moderate/severe acne reported a lower quality of life compared to participants without acne (P<0.001).

CONCLUSIONS

The results from this cross-sectional study suggest a relationship between dietary carbohydrate, including GL, and acne. Future research is necessary to determine the effect of medical nutrition therapy on biological factors associated with acne and acne severity.

Acne vulgaris: Perceptions and beliefs of Saudi adolescent males

INTRODUCTION:

Although acne vulgaris is common in adolescents, information on their understanding of acne is minimal.

OBJECTIVES:

To evaluate the perceptions and beliefs of Saudi youth on acne.

MATERIALS AND METHODS:

Three hundred twenty-nine male students (aged 13–22 years) from 6 secondary schools in the Eastern Saudi Arabia completed a self-reported questionnaire on knowledge, causation, exacerbating and relieving factors of acne. Data were analyzed by SPSS version 15.0. Results of subjects with acne, a family history of acne, and parents' educational levels were compared. Differences between the analyzed groups were assessed by a Chi-square test; p ≤ 0.05 was considered statistically significant.

RESULTS:

Over half (58.9%) of the participants considered acne a transient condition not requiring therapy. Only 13.1% knew that the proper treatment of acne could take a long time, even several years. Over half (52%) thought acne can be treated from the first or after few visits to the doctor. Popular sources of information were television/radio (47.7%), friends (45.6%), and the internet (38%). Only 23.4% indicated school as a source of knowledge. Reported causal factors included scratching (88.5%) and squeezing (82.1%) of pimples, poor hygiene (83.9%), poor dietary habits (71.5%), and stress (54.1%). Ameliorating factors included frequent washing of the face (52.9%), exercise (41.1%), sunbathing (24.1%), and drinking of mineral water (21%). The correlations of these facts are discussed.

CONCLUSION:

Results of this study point out that misconceptions of acne are widespread among Saudi youth. A health education program is needed to improve the understanding of the condition.

Acne and dairy products in adolescence: results from a Norwegian longitudinal study

BACKGROUND

Acne is a very common skin condition, and it is of great interest to elucidate lifestyle factors that may contribute to its occurrence. In the last decade, the acne-diet connection has been brought back to credibility.

OBJECTIVE

To examine whether high intakes of dairy products in early adolescence is associated with moderate to severe acne in later adolescence.

METHODS

The study is a longitudinal, questionnaire-based population study of Norwegian adolescents. Students attending the 10th grade (15-16 years old) of compulsory schooling in Oslo in 2000-2001 and the 13th grade (18-19 years old) 3 years later, in 2004, were invited. Dairy product consumption was self-reported at age 15-16 and acne severity was self-assessed and reported at age 18-19.

RESULTS

The overall prevalence of moderate to severe acne was 13.9%. High intakes (≥2 glasses per day) of full-fat dairy products were associated with moderate to severe acne. In boys with exclusively high intakes of full-fat dairy products, the odds ratio for acne was 4.81 (1.59-14.56). A high total intake of dairy products was associated with acne in girls (OR 1.80, 1.02-3.16). No significant associations were found between acne and intake of semi-skimmed or skimmed dairy products, and not with moderate intakes of any fat variety of dairy products.

CONCLUSION

This study shows association between high intakes of dairy products and acne in adolescence. Our findings support a hypothesis suggesting that dairy consumption may be a factor contributing to acne. The study is based on multiple hypothesis testing, and the methodological limitations must be considered when interpreting the results.

The epidemiology of acne vulgaris in late adolescence

Importance

Acne vulgaris is the most common skin condition affecting late adolescents across the globe. Although prior studies have evaluated epidemiologic patterns of acne vulgaris in various ethnicities and regions, adequate understanding of the worldwide burden of the disease associated with patients in their late adolescence (15–19-year olds) remains lacking.

Objective

To assess the global burden of the disease associated with acne vulgaris for late adolescents (15–19-year olds) and provide an overview of the epidemiology, pathophysiology, and treatment options for acne in this population.

Design

Database summary study.

Setting

Global Burden of Disease Study 2010 database.

Participants

Global Burden of Disease regions comprised countries with prevalence of acne vulgaris between the ages of 15 and 19 years.

Main outcomes and measures

Geographic region-level disability-adjusted life year rates (per 100,000 persons) associated with acne vulgaris in years 1990 through 2010. Median percentage change in disability-adjusted life year rates was estimated for each region across the specified study period.

Conclusion and relevance

Acne vulgaris-associated disease burden exhibits global distribution and has continued to grow in prevalence over time within this population. This continued growth suggests an unmet dermatologic need worldwide for this disorder and potential opportunities for improved access and delivery of dermatologic care. Our analysis of the literature reveals numerous opportunities for enhanced patient care. To that end, we highlight some of the effective and promising treatments currently available and address important factors, such as sex, nationality, genetics, pathophysiology, and diet, as they relate to acne vulgaris in late adolescence.

The constellation of dietary factors in adolescent acne: a semantic connectivity map approach

BACKGROUND

Different lifestyle and dietetic factors have been linked with the onset and severity of acne.

OBJECTIVE

To assess the complex interconnection between dietetic variables and acne.

METHODS

This was a reanalysis of data from a case-control study by using a semantic connectivity map approach. 563 subjects, aged 10-24 years, involved in a case-control study of acne between March 2009 and February 2010, were considered in this study. The analysis evaluated the link between a moderate to severe acne and anthropometric variables, family history and dietetic factors. Analyses were conducted by relying on an artificial adaptive system, the Auto Semantic Connectivity Map (AutoCM).

RESULTS

The AutoCM map showed that moderate-severe acne was closely associated with family history of acne in first degree relatives, obesity (BMI ≥ 30), and high consumption of milk, in particular skim milk, cheese/yogurt, sweets/cakes, chocolate, and a low consumption of fish, and limited intake of fruits/vegetables.

CONCLUSION

Our analyses confirm the link between several dietetic items and acne. When providing care, dermatologists should also be aware of the complex interconnection between dietetic factors and acne.

Linking diet to acne metabolomics, inflammation, and comedogenesis: an update

Acne vulgaris, an epidemic inflammatory skin disease of adolescence, is closely related to Western diet. Three major food classes that promote acne are: 1) hyperglycemic carbohydrates, 2) milk and dairy products, 3) saturated fats including trans-fats and deficient ω-3 polyunsaturated fatty acids (PUFAs). Diet-induced insulin/insulin-like growth factor (IGF-1)-signaling is superimposed on elevated IGF-1 levels during puberty, thereby unmasking the impact of aberrant nutrigenomics on sebaceous gland homeostasis. Western diet provides abundant branched-chain amino acids (BCAAs), glutamine, and palmitic acid. Insulin and IGF-1 suppress the activity of the metabolic transcription factor forkhead box O1 (FoxO1). Insulin, IGF-1, BCAAs, glutamine, and palmitate activate the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), the key regulator of anabolism and lipogenesis. FoxO1 is a negative coregulator of androgen receptor, peroxisome proliferator-activated receptor-γ (PPARγ), liver X receptor-α, and sterol response element binding protein-1c (SREBP-1c), crucial transcription factors of sebaceous lipogenesis. mTORC1 stimulates the expression of PPARγ and SREBP-1c, promoting sebum production. SREBP-1c upregulates stearoyl-CoA- and Δ6-desaturase, enhancing the proportion of monounsaturated fatty acids in sebum triglycerides. Diet-mediated aberrations in sebum quantity (hyperseborrhea) and composition (dysseborrhea) promote Propionibacterium acnes overgrowth and biofilm formation with overexpression of the virulence factor triglyceride lipase increasing follicular levels of free palmitate and oleate. Free palmitate functions as a "danger signal," stimulating toll-like receptor-2-mediated inflammasome activation with interleukin-1β release, Th17 differentiation, and interleukin-17-mediated keratinocyte proliferation. Oleate stimulates P. acnes adhesion, keratinocyte proliferation, and comedogenesis via interleukin-1α release. Thus, diet-induced metabolomic alterations promote the visible sebofollicular inflammasomopathy acne vulgaris. Nutrition therapy of acne has to increase FoxO1 and to attenuate mTORC1/SREBP-1c signaling. Patients should balance total calorie uptake and restrict refined carbohydrates, milk, dairy protein supplements, saturated fats, and trans-fats. A paleolithic-like diet enriched in vegetables and fish is recommended. Plant-derived mTORC1 inhibitors and ω-3-PUFAs are promising dietary supplements supporting nutrition therapy of acne vulgaris.

Diet in dermatology: Part I. Atopic dermatitis, acne, and nonmelanoma skin cancer

Patients commonly inquire about dietary modifications as a means to prevent or manage skin disease. Answering these questions is often challenging, given the vast and conflicting evidence that exists on this topic. This 2-part continuing medical education article summarizes the evidence to date to enable physicians to answer patients' questions in an evidence-based manner. Part I includes atopic dermatitis, acne, and nonmelanoma skin cancer. The role of dietary supplementation, dietary exclusion, food allergy, maternal diet, and breastfeeding in the development and/or prevention of atopic dermatitis is summarized. The dermatoendocrinologic mechanism for the effects of glycemic index/glycemic load and milk on acne is described, as well as related clinical evidence for dietary modifications. Finally, evidence and recommendations for restriction or supplementation of dietary factors in the prevention of nonmelanoma skin cancer, including fat, vitamins A, C, D, and E, and selenium, are reported.