The effect of milk consumption on acne: a meta-analysis of observational studies

The adjuvant treatment role of ω-3 fatty acids by regulating gut microbiota positively in the acne vulgaris

Objectives:We aimed to explore the potential role of omega-3 (ω-3) fatty acids on acne vulgaris by modulating gut microbiota.Materials and Methods:We randomly divided the untreated acne patients into two groups with or without ω-3 fatty acids intervention for 12 weeks. The Sprague Dawley (SD) rats with acne model were given isotretinoin, ω-3 fatty acids or their combination respectively. Then the colonic contents samples of the drug intervention SD rats were transferred to the pseudo sterile rats with acne model. The severity of the disease was assessed by the Global Acne Grading System (GAGS) score of the patients, and the swelling rate of auricle and the pathological section of the rat with acne model. The 16S rDNA gene sequencing was performed to detect the alteration of the gut microbiota.Results:ω-3 fatty acids could increase the diversity of the gut microbiota and regulate the flora structure positively both in the patients and rats, increase the abundance of butyric acid producing bacteria and GAGS score in the patients, and alleviate the inflammation and comedones of rats.Conclusion:Supplementation of ω-3 fatty acids could alleviate the inflammation of acne vulgaris by increasing the abundance of butyric acid producing bacteria.

Recommendations for managing adult acne and adolescent acne based on an epidemiological study conducted in China

There are numerous differences between adult acne and adolescent acne in terms of causes, distribution, and characteristics of skin lesions, as well as treatment. This paper aims to summarize the differences between adult and adolescent acne in China, in order to propose more suitable ways to improve their quality of life. We collected basic information, acne-related information, acne-affecting factors, quality of life scores and treatment-related information of acne patients. A total of 552 questionnaires were collected. Adult acne is typically predominant on the cheeks, similar to adolescent acne, with a relatively lower incidence in other areas, apart from the jawline. Pigmentation and depressed scars are present in nearly half of acne patients, while hypertrophic scars are less frequently observed. Teenagers often have a higher consumption of dairy products, sugary drinks, and high-sugar and high-fat foods. Eczema is more common in adult acne. Additionally, more adults than teenagers experience stress and poor quality of life related to acne. Adolescents are more likely to seek treatment online and on social media. Clinicians must thoroughly evaluate diverse risk factors and formulate personalized acne management strategies for patients with different types of acne.

The Effect of Whey Protein Supplements on Acne Vulgaris among Male Adolescents and Young Adults: A Case-Control Study from North of Jordan

Background

Young people and athletes willing to gain muscle mass and strength are likely to consume whey protein supplements. The effect of milk as a dietary source of whey protein on acne is still controversial. At the same time, a few studies have suggested an acnegenic impact of whey protein supplements.

Objectives

To examine the association of whey protein supplements on acne risk among male adolescents and young adults.

Materials and Methods

201 male teenagers and young adults attending fitness centers in Irbid/Jordan were involved in an observational case-control research; those with acne were deemed cases, and those without acne were considered controls. The primary outcome was a comparison of the proportion of participants in each group who consumed whey protein supplements within the previous three months.

Results

100 acne-afflicted participants were compared to 101 healthy controls with similar demographics, including age, body mass index, educational level, and smoking habits, as well as intake of vitamin B12, corticosteroids, and anabolic steroids. However, considerably more participants in the acne group (47%) were taking whey protein supplements than in the control group (27.7%) (p=0.0047). The significance of this difference was maintained after multivariate analysis.

Conclusion

This case-control study provides evidence of a positive association between whey protein consumption and acne risk.

A review of dairy food intake for improving health among black children and adolescents in the US

Adequate nutrition during childhood and adolescence is crucial for proper neurological, musculoskeletal, immunological, and cardiometabolic health and development. Yet, disparities among socially underserved racial/ethnic groups in the United States (US) provide significant challenges to achieving adequate nutrition during these years of rapid growth and maturation. For example, Black children and adolescents are at greater risk for having food insecurity, lower-quality diets, obesity, and numerous associated health challenges that result from these disparities compared to their White peers. A growing body of evidence indicates that improving diet quality is critical for improving childhood and adolescent health and well-being, and that the diverse nutritional profile and bioactive compounds found within dairy foods may play multiple roles in promoting proper growth and development during these life stages. Therefore, to support overall health and development among Black youth, greater education and implementation efforts are needed to help this population meet the national dietary recommendations of 2.5 to 3 servings of dairy foods per day. Continuing to fall short of these recommendations puts Black children and adolescents at risk of multiple nutrient inadequacies and health disparities that can have lifelong impacts on disease development, mental health, and quality of life. This review presents the state of knowledge on health disparities and modifiable nutritional strategies involving milk and dairy foods to support the growth and maturation of children and adolescents, with a special focus on Black youth in the US.

The role of dairy food intake for improving health among black Americans across the life continuum: A summary of the evidence

Decades of health data show major health disparities occurring at every life stage between Black and White Americans. These disparities include greater mortality rates among Black mothers and their offspring, higher levels of malnutrition and obesity among Black children and adolescents, and a higher burden of chronic disease and lower life expectancy for Black adults. Although nutrition is only one of many factors that influence human health and well-being across the life continuum, a growing body of research continues to demonstrate that consuming a healthy dietary pattern is one of the most dominant factors associated with increased longevity, improved mental health, improved immunity, and decreased risk for obesity and chronic disease. Unfortunately, large percentages of Black Americans tend to consume inadequate amounts of several essential nutrients such as vitamin A, vitamin D, calcium, and magnesium; and simultaneously consume excessive amounts of fast foods and sugar-sweetened beverages to a greater degree than other racial/ethnic groups. Therefore, strategies that can help improve dietary patterns for Black Americans could make up a major public health opportunity for reducing nutrition-related diseases and health disparities across the life course. A key intervention strategy to improve diet quality among Black Americans is to focus on increasing the intake of nutrient-rich dairy foods, which are significantly underconsumed by most Black Americans. Compared to other food group, dairy foods are some of the most accessible and affordable sources of essential nutrients like vitamin A, D, and B12, calcium, magnesium, potassium, selenium, and zinc in the food supply, as well as being some of the primary sources of several health-promoting bioactive compounds, including polar lipids, bioactive proteins and peptides, oligosaccharides, and live and active cultures in fermented products. Given the complex relationships that many Black Americans have with dairy foods, due to issues with lactose intolerance, and/or negative perceptions about the health effects of dairy foods, there is still a need to examine the role that dairy foods play in the health and well-being of Black Americans of all ages and life stages. Therefore, the National Medical Association and its partners have produced multiple reports on the value of including adequate dairy in the diet of Black Americans. This present summary paper and its associated series of evidence reviews provide an examination of an immense amount of research focused on dairy intake and health outcomes, with an emphasis on evidence-based strategies for improving the health of Black Americans. Overall, the findings and conclusions from this body of research continue to indicate that higher dairy intake is associated with reduced risk for many of the most commonly occurring deficiencies and diseases impacting each life stage, and that Black Americans would receive significantly greater health benefits by increasing their daily dairy intake levels to meet the national recommendations than they would from continuing to fall short of these recommendations. However, these recommendations must be considered with appropriate context and nuance as the intake of different dairy products can have different impacts on health outcomes. For instance, vitamin D fortified dairy products and fermented dairy products like yogurt - which are low in lactose and rich in live and active cultures - tend to show the greatest benefits for improved health. Importantly, there are significant limitations to these research findings for Black Americans, especially as they relate to reproductive and child health, since most of the research on dairy intake and health has failed to include adequate representation of Black populations or to sufficiently address the role of dairy intake during the most vulnerable life stages, such as pregancy, lactation, fetal development, early childhood, and older age. This population and these life stages require considerably more research and policy attention if health equity is ever to be achieved for Black Americans. Sharing and applying the learnings from this summary paper and its associated series of evidence reviews will help inform and empower nutrition and health practitioners to provide more evidence-based dietary recommendations for improving the health and well-being of Black Americans across the life course.

Dietary Patterns in Acne and Rosacea Patients-A Controlled Study and Comprehensive Analysis

As the relationship between exposome factors and inflammatory skin diseases is gaining increasing attention, the objective of this study was to investigate dietary patterns among acne and rosacea patients and to establish the disease risk attributable to nutrition. In this cross-sectional, controlled study, patients' dietary habits were assessed via subjective ratings of beneficial and trigger foods, followed by standardized food frequency surveys (FFS). Scores for disease-specific risk stratification based on dietary habits were proposed. Clinical assessments, dermatologic examinations, and laboratory analyses were performed. A total of 296 patients (acne group (AG) n = 120, control group (ACG) n = 32; rosacea group (RG) n = 105, control group (RCG) n = 39) were included. The significant impact of diet on disease severity was self-reported by 80.8% of the AG and 70.5% of the RG. Leading dietary triggers were found in both groups, while beneficial food items were identified more clearly by the AG. FFS revealed significant dietary differences between the AG, RG, and control groups. Disease-specific scores showed greater precision for acne (odds ratio 14.5 AG, 5.5 RG). The AG had higher insulin-like growth factor (IGF)-1 levels correlating with dairy intake (p = 0.006). Overall, this study underlines the influence of diet on acne and rosacea, providing valuable disease-specific scores for dietary risk stratification. Consuming vegetables, legumes, oily fish, olive oil, and nuts, and limiting meat, cheese, and alcohol appear to be beneficial for both acne and rosacea. Future studies can build on these data to further improve preventive and therapeutic strategies.

Effects of donkey milk on UVB-induced skin barrier damage and melanin pigmentation: A network pharmacology and experimental validation study

Introduction

Dairy products have long been regarded as a controversial nutrient for the skin. However, a clear demonstration of donkey milk (DM) on skincare is required.

Methods

In this study, spectrum and chemical component analyses were applied to DM. Then, the effects of DM on UVB-induced skin barrier damage and melanin pigmentation were first evaluated in vitro and in vivo. Cell survival, animal models, and expression of filaggrin (FLG) were determined to confirm the effect of DM on UVB-induced skin barrier damage. Melanogenesis and tyrosinase (TYR) activity were assessed after UVB irradiation to clarify the effect of DM on whitening activities. Further, a network pharmacology method was applied to study the interaction between DM ingredients and UVB-induced skin injury. Meanwhile, an analysis of the melanogenesis molecular target network was developed and validated to predict the melanogenesis regulators in DM.

Results

DM was rich in cholesterols, fatty acids, vitamins and amino acids. The results of evaluation of whitening activities in vitro and in vivo indicated that DM had a potent inhibitory effect on melanin synthesis. The results of effects of DM on UVB‑induced skin barrier damage indicated that DM inhibited UVB-induced injury and restored skin barrier function via up-regulation expression of FLG (filaggrin). The pharmacological network of DM showed that DM regulated steroid biosynthesis and fatty acid metabolism in keratinocytes and 64 melanin targets which the main contributing role of DM might target melanogenesis, cell adhesion molecules (CAMs), and Tumor necrosis factor (TNF) pathway.

Discussion

These results highlight the potential use of DM as a promising agent for whitening and anti-photoaging applications.

The Impact of Kefir on Epidermal Water Homeostasis in Healthy Human Skin

Kefir, a symbiotic consortium of diverse bacteria and yeasts, is one of the most popular probiotic foods on the market. Its consumption has been referred to as beneficial in human skin health, namely in the reinforcement of skin's barrier function. This benefit likely results from the productive activity of lactic acid bacteria during kefir fermentation. Lactic acid is naturally present in the skin, and actively contributes to epidermal water dynamics and "barrier." Few studies have been conducted regarding the impact of probiotic consumption in human epidermal water homeostasis. Therefore, this study was designed to explore the impact of the regular consumption of kefir on the skin water dynamics in a group of participants with healthy skin. Participants (n = 27) were healthy female volunteers from whom twelve consumed 100 mL of kefir every day for eight weeks as part of their diet. The remaining (untreated) participants served as the control group. Epidermal water balance was assessed by measuring transepidermal water loss (TEWL) and stratum corneum (SC) hydration on three different occasions-at baseline (T0), after four weeks (T4) and after eight weeks (T8) of interventive kefir consumption. Our study revealed a significant reduction in TEWL (p = 0.043) in the kefir group after eight weeks of regular consumption. In the same period, no differences were found for TEWL in the control group (p = 0.997). Regarding hydration, skin dryness was progressive in the control group, with a significant reduction in SC hydration (p = 0.002) at T8 in comparison to T0. In the kefir group, SC hydration was preserved between T0 and T8 (p = 0.997), which we believe to be related to epidermal "barrier" reinforcement. Our study seems to confirm that the regular consumption of kefir does improve cutaneous water balance even in healthy skin.

The impact of clinical nutrition on inflammatory skin diseases

The influence of nutrition on the pathophysiology and clinical severity of inflammatory facial dermatoses such as acne, rosacea, seborrheic dermatitis, and perioral dermatitis has been controversially discussed for years. As part of a modern treatment approach, clinicians should provide patients with information on how their choice of diet might impact their dermatologic diagnosis and could potentially enhance therapeutic outcome. Recently, the concept of a gut-skin axis has gained momentum in the understanding of inflammatory dermatoses, with nutrition considered a contributing factor in this context. For example, gastrointestinal symptoms in rosacea patients may indicate a dysbiosis of the gut microbiome, treatment of which may also improve severity of the skin disease. New research efforts were recently made for acne patients addressing the clinical effects of omega-3 fatty acids and probiotics. In contrast, due to the limited data available, no comparable specific dietary recommendations can yet be made for seborrheic or perioral dermatitis. However, there are promising signs that clinical nutrition and dermatology will be more extensively interlinked in the future, both clinically and scientifically.

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).

Dermatology: how to manage acne vulgaris

Background

Acne vulgaris is the most common skin disease that can lead to disfigurement and psychological distress. This article aims to provide a narrative updated review on the management of acne vulgaris.

Methods

A PubMed search was performed with Clinical Queries using the key term “acne”. The search strategy included clinical trials, meta-analyses, randomized controlled trials, observational studies and reviews. The search was restricted to articles published in English.

Results

Treatments of acne include proper skin care, topical medications, oral medications and procedural therapies. Topical agents are the first-line treatment for mild-to-moderate acne and can be used as combination therapy for more severe acne. Systemic therapies are usually prescribed for the initial treatment of moderate-to-severe acne as well as for acne that is refractory to topical therapies.

Conclusion

Topical retinoids are the drugs of choice for the treatment and maintenance therapy of patients with mild-to-moderate acne vulgaris. Depending on the severity of the acne, topical retinoids may be used alone or in combination with benzoyl peroxide and topical or oral antibiotics. Oral antibiotics are an important therapy for inflammatory acne unresponsive to topical therapy. Neither topical nor oral antibiotics should be used as monotherapy. Oral contraceptives and/or spironolactone are useful for many women with acne. Oral isotretinoin is the drug of choice for severe, extensive, nodular acne vulgaris but is also often used in moderate cases where scarring is evident, acne-related psychosocial distress is significant or other treatment modalities have failed.

Phase angle and Mediterranean diet in patients with acne: Two easy tools for assessing the clinical severity of disease

BACKGROUND

Acne is a chronic, inflammatory and debilitating skin disorder. Dietary factors and nutritional status are among the exacerbating factors of acne. Phase angle (PhA), a direct measure of Bioelectrical Impedance Analysis (BIA), represents an indicator of the chronic inflammatory state. The Mediterranean diet (MD) is a healthy dietary pattern that can exert anti-inflammatory effects in several inflammatory diseases. We aimed to investigate the difference in PhA and adherence to the MD and their associations with the severity of acne in a sample of naïve treatment patients with acne compared to control group.

MATERIALS

In this cross-sectional, case-control, observational study, we enrolled 51 patients with acne and 51 control individuals. Body composition was evaluated by a BIA phase-sensitive system (50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy, Akern). For adherence to the MD, we have used the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. The clinical severity of acne was assessed by using the global acne grading system (GAGS), a quantitative scoring system to assess acne severity.

RESULTS

Patients with acne had a worse body composition, in particular smaller PhA (p = 0.003), and a lower adherence to the MD (p < 0.001) than the control group, in spite of no differences in gender, age and BMI between the two groups. Stratifying patients with acne according to GAGS categories, both PhA (p = 0.006) and PREDIMED score (p = 0.007) decreased significantly in severe acne than mild/moderate acne. The GAGS score was negative correlations with PhA (r = - 0.478, p < 0.001) and PREDIMED score (r = - 0.504, p < 0.001). The results of the multivariate analysis showed PhA and PREDIMED score were the major determinants of GAGS score (p < 0.001). The receiver operator characteristic (ROC) analysis reporting a value of PhA of ≤ 6.1° and a PREDIMED score of ≤ 9 identified patients with acne with the highest clinical severity of the disease.

CONCLUSIONS

Novel correlations were reported between PhA and the degree of adherence to the MD with acne severity. Of interest, PhA and PREDIMED scores might represent possible markers of the severity of acne in a clinical setting. This study highlights how a cooperation between dermatologist and nutritionists might provide a combination key in the complex management of acne patients.

Lifetime Impact of Cow's Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

The consumption of cow's milk is a part of the basic nutritional habits of Western industrialized countries. Recent epidemiological studies associate the intake of cow's milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review presents current epidemiological and translational evidence linking milk consumption to the regulation of mTORC1, the master-switch for eukaryotic cell growth. Epidemiological studies confirm a correlation between cow's milk consumption and birthweight, body mass index, onset of menarche, linear growth during childhood, acne vulgaris, type 2 diabetes mellitus, prostate cancer, breast cancer, hepatocellular carcinoma, diffuse large B-cell lymphoma, neurodegenerative diseases, and all-cause mortality. Thus, long-term persistent consumption of cow's milk increases the risk of mTORC1-driven diseases of civilization. Milk is a highly conserved, lactation genome-controlled signaling system that functions as a maternal-neonatal relay for optimized species-specific activation of mTORC1, the nexus for regulation of eukaryotic cell growth, and control of autophagy. A deeper understanding of milk´s impact on mTORC1 signaling is of critical importance for the prevention of common diseases of civilization.

Diet and acne: review of the evidence from 2009 to 2020

BACKGROUND

Dietary habits may play a non-negligible role in the development, duration, and severity of acne, as shown in past critical review articles on such association.

METHODS

The aim of this systematic review is to supplement data available on scientific literature spanning the last 10 years by inserting the keywords "acne" or "acne vulgaris" and "diet", "nutrition", "food", "chocolate", "dairy", "whey protein", "fatty acid", or "drink" in the timeframe "January 2009-April 2020" within the PubMed database.

RESULTS

Fifty-three reviewed articles met eligibility criteria. They included 11 interventional clinical trials (seven randomized controlled trials and four uncontrolled open label studies) and 42 observational studies (17 case-control and 22 cross-sectional studies, and three descriptive studies).

CONCLUSIONS

This review reinforces the notion of a rapidly growing exponential trend of interest in this subject by the scientific community. Acne-promoting factors include high GI/GL food, dairy products, fat food, and chocolate, whereas acne-protective factors include fatty acids, fruit, and vegetable intake. The role played by specific dietary components pertaining to different foods, as done for milk (full-fat/whole, reduced-fat, low-fat/skim milk), dairy products (milk cream, ice cream, yogurt, cheese, etc.), or chocolate (cocoa, dark/milk chocolate), remains an unsolved issue and objective of future research.

The assessment of psychology, quality of life in acne patients and evaluation of ALA-PDT for moderate to severe acne

OBJECTIVE

To evaluate the state of psychology and quality of life of patients effected by acne and also the efficacy and safety of photodynamic therapy with topical 5-aminolevulinic acid (ALA-PDT) for moderate to severe acne patients.

METHODS

In the questionnaire part, a pre-designed form was filled out. The questionnaire was comprised of 2 sections related to acne including sociodemographic and disease information as well as Cardiff Acne Disability Index (CADI) and Self-Rating Anxiety Scale (SAS). In the trial part, the ALA-PDT was applied to moderate to severe acne patients. Fresh 5% ALA solution was topically applied to face or face & neck. After 1 h's incubation, a LED device was illuminated. A power density of 60-100 mW/cm² was delivered for 20 min. All the patients finished 3-4 sessions of ALA-PDT at 7-10 days intervals. Non-invasive detections were taken for skin moisture, oil, and VISIA indexes. Adverse events were recorded during and after the treatment.

RESULTS

A total of 247 acne patients finished questionnaires. Over 97 % patients were assessed as mild to severe impacts in CADI questionnaire and 37.6 % patients had various degrees of anxiety in SAS questionnaire. The higher the BMI was, the higher the CADI points were (G = 0.278, p = 0.005). The severity of acne was correlated with psychology and quality of life (CADI: G = 0.367, p = 0.000; SAS: G = 0.285, p = 0.003). A total of 116 patients with moderate or severe acne accepted ALA-PDT and completed at least 3 sessions (PDT3) or even PDT4. After 1 session of treatment (AT1) and AT2, the efficiencies of all patients were 5.2 % and 29.3 %. For patients with PDT3, the efficiencies at follow-up at 1st month after last session (FU1), FU2 and FU3 were 59.4 %, 66.7 % and 78.3 %, respectively. For patients with PDT4, the efficiencies at AT3 and FU1-3 were 51.3 %, 63.6 %, 76.5 % and 85.7 %, respectively. The efficacies of PDT4 patients showed an increasing trend from FU1 to FU3 (G = 0.480, p = 0.004). Acne lesions of mild to severe were correlated with the treatment efficacies (FU1: G = 0.354, p = 0.000; FU2: G = 0.474, p = 0.000; FU3: G = 0.397, p = 0.000). Nearly 15 % patients were followed up for 12 months and among them 52.9 % patients were able to maintain ≥90 % improvement rate. There were no statistically significant differences before and after treatment (p > 0.05) according to the skin moisture content, oil content, ultraviolet ray spots, brown spots, red areas, and purple textures measured. The adverse reactions of ALA-PDT, including local burning sensation, mild pain sensation, mild edema erythema, reactive acne, pigmentation, etc., were temporary and tolerable.

CONCLUSION

In our study, 97.2 % patients were rated as impact in CADI questionnaire and 37.6 % patients had anxiety in SAS questionnaire. It is necessary to control weight and disease progression. The efficiencies of ALA-PDT for moderate and severe acne were 59.4%-85.7% at follow-ups of 1st, 2nd or 3rd month after last session. The adverse reactions of ALA-PDT were temporary and tolerable.

Systematic review of the epidemiology of acne vulgaris

A systematic review was conducted on epidemiology studies on acne obtained from a Web of Science search to study risk factors associated with acne presentation and severity. A strong association was observed between several risk factors – family history, age, BMI and skin type – and acne presentation or severity in multiple studies. The pooled odds ratio of 2.36 (95% CI 1.97–2.83) for overweight/obese BMI with reference to normal/underweight BMI and the pooled odds ratio of 2.91 (95% CI 2.58–3.28) for family history in parents with reference to no family history in parents demonstrate this strong association. In addition, a pooled odds ratio of 1.07 (95% CI 0.42–2.71) was obtained for sex (males with reference to females). However, the association between other factors, such as dietary factors and smoking, and acne presentation or severity was less clear, with inconsistent results between studies. Thus, further research is required to understand how these factors may influence the development and severity of acne. This study summarizes the potential factors that may affect the risk of acne presentation or severe acne and can help researchers and clinicians to understand the epidemiology of acne and severe acne. Furthermore, the findings can direct future acne research, with the hope of gaining insight into the pathophysiology of acne so as to develop effective acne treatments.

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.