Psoriasis is a common, chronic, immune-mediated skin disease with systemic pro-inflammatory activation, where both environmental and genetic factors contribute to its pathogenesis. Among the risk factors for psoriasis, evidence is accumulating that nutrition plays a major role, per se, in psoriasis pathogenesis. In particular, body weight, nutrition, and diet may exacerbate the clinical manifestations, or even trigger the disease. Understanding the epidemiological relationship between obesity and psoriasis is also important for delineating the risk profile for the obesity-related comorbidities commonly found among psoriatic patients. Moreover, obesity can affect both drug’s pharmacokinetics and pharmacodynamics. Additionally, the overall beneficial effects on the obesity-associated comorbidities, clinical recommendations to reduce weight and to adopt a healthy lifestyle could improve the psoriasis severity, particularly in those patients with moderate to severe disease, thus exerting additional therapeutic effects in the conventional treatment in obese patients with psoriasis. Education regarding modifiable environmental factors is essential in the treatment of this disease and represents one of the primary interventions that can affect the prognosis of patients with psoriasis. The goal is to make psoriatic patients and health care providers aware of beneficial dietary interventions. The aim of this review is to assess the relevance of the environmental factors as modifiable risk factors in psoriasis pathogenesis, with particular regard to the involvement of obesity and nutrition in the management of psoriasis, providing also specific nutrition recommendations.

The Mediterranean diet is a healthy dietary pattern known to actively modulate the cell membrane properties. Phase angle (PhA) is a direct measure by Bioelectrical Impedance Analysis (BIA) used as marker of cell membrane integrity. Both food behaviour and PhA are influenced by age, sex and body weight. The aim of this study was to cross-sectionally evaluate the association between the adherence to Mediterranean diet and PhA in 1013 healthy adult patients stratified according to sex, age, and body mass index (BMI). The adherence to the Mediterranean diet was evaluated using the PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. PhA was calculated by BIA phase-sensitive system (50 kHz BIA 101 RJL, Akern Bioresearch, Florence, Italy Akern). In both sexes, at ROC analysis a PREDIMED score ≥ 6 predicted a PhA beyond the median value. At the multivariate analysis, among PREDIMED score, age, and BMI, the PREDIMED score was the major determinant of PhA, explaining 44.5% and 47.3% of PhA variability, in males and females respectively (p < 0.001). A novel association was reported between the adherence to the Mediterranean diet and PhA, independently of sex, age, and body weight. This association uncovered a new potential benefit of the Mediterranean diet on health outcomes, as in both sexes higher adherence to the Mediterranean diet was associated to larger PhAs, as expression of cell membrane integrity.

Nutrition is an environmental factor affecting bone health. Nutrition is considered essential to achieve and maintain optimal bone mass. Mediterranean diet (MD) has shown to prevent bone disease. Aim of this study is to investigate the relationship between bone health status and adherence the MD. Four-hundred eighteen healthy people (105 males and 313 females, age 50 ± 14 years) were recruited in the outdoor hospital of the “Campus Salute Onlus” held in Piazza del Plebiscito in Naples, October 17–20th 2013 and 09–11th October 2014. All subjects underwent clinical assessment, calcaneal quantitative ultrasound (QUS) scanner and PREvención con DIeta MEDiterránea (PREDIMED) questionnaire. Globally, prevalence of osteoporosis and osteopenia were 7.7 and 46.0%, respectively. The majority of subjects (60.5%) had an average score (score 6–9) of adherence to MD. The T-score showed positive correlation with PREDIMED score (r = 0.250, p < 0.001). The higher T-scores were positively associated with a higher consumption of extra-virgin olive oil (EVOO), vegetables, fruits, legumes, and fish and negatively associated with consumption of red meat. The higher T-scores were positively associated with the highest odds of PREDIMED scores (higher adherence) (OR 6.91, IC 6.27–7.61, p < 0.001). Multiple regression analysis models indicated that, among the single food items investigated, high T-score can be predicted by consumption of EVOO (p < 0.001), fish (p < 0.001) and fruit (p = 0.002) intake. A PREDIMED score of 3 was found to be predictive for a low T-score (α = 0.05, R-squared index = 0.417). The results demonstrate a positive correlation between bone health status and adherence to MD, suggesting that a high adherence to MD promotes bone health. The observations here reported confirmed that a specific dietary approach, such as MD, can represent a modifiable environmental factor for osteoporosis’ prevention.

Nutrition is the major environmental factor that influences the risk of developing pathologies, such as obesity. Although a number of recent reviews pinpoint a protective effects of milk on body weight and obesity related co-morbidities, an inaccurate estimate of milk might contribute to hamper its beneficial effects on health outcomes. Seven-day food records provide prospective food intake data, reducing recall bias and providing extra details about specific food items. Milk intake stimulates the somatotropic axis at multiple levels by increasing both growth hormone (GH) and insulin-like growth factor-1 (IGF-1) secretion. On the other hand, obesity is associated with reduced spontaneous and stimulated GH secretion and basal IGF-1 levels. Aim of this study was to evaluate the milk consumption by using the 7-days food record in obese individuals and to investigate the association between milk intake and GH secretory status in these subjects. Cross-sectional observational study carried out on 281 adult individuals (200 women and 81 men, aged 18-74 years) with moderate-severe obesity (BMI 35.2-69.4 kg/m2). Baseline milk intake data were collected using a 7 day food record. Anthropometric measurements and biochemical profile were determined. The GH/IGF-1 axis was evaluated by peak GH response after GHRH + ARGININE and IGF-1 standard deviation score (SDS). The majority of individuals (72.2%) reported consuming milk; 250 mL low-fat milk was the most frequently serving of milk consumed, while no subjects reported to consume whole milk. Milk consumers vs no milk consumers presented the better anthropometric measurements and metabolic profile. At the bivariate proportional odds ratio model, after adjusting for BMI, age and gender, milk consumption was associated the better GH status (OR = 0.60; p < 0.001). Among milk consumers, subjects consuming 250 mL reduced-fat milk vs 250 mL low-fat milk presented the better anthropometric measurements and metabolic profile. At the bivariate proportional odds ratio model, after adjusting for BMI, age and gender, the consume of 250 mL reduced-fat milk was associated better GH status (OR = 0.54; p = 0.003). A novel positive association between milk consumption, GH status, and metabolic profile in obese individuals was evidenced. Regardless of the pathogenetic mechanisms, this novel association might be relevant in a context where commonly obese individuals skip breakfast, and suggests the need of a growing cooperation between Nutritionists and Endocrinologists in the management of the obese patients.

Obesity, metabolic syndrome (MetS), and psoriasis, largely driven by environmental factors, show multiple bidirectional associations, with important metabolic implications in psoriatic patients. Besides body mass index (BMI) as a measure of obesity, data on phase angle (PhA), a direct measure by bioelectrical impedance analysis (BIA), used as a marker of cellular health and a predictor of morbidity and mortality in various diseases, are still lacking in psoriasis. In this case–control, cross-sectional study, we investigated the PhA in 180 pairs of adult psoriatic patients and healthy controls, evaluating also the potential use of the PhA as marker of the clinical severity, the quality of life, and the presence of the MetS in psoriatic patients. Anthropometric measures, metabolic profile and bioelectrical variables were evaluated. The clinical severity was assessed by standardized psoriasis area and severity index (PASI) score and c-reactive protein (CRP) levels, and the quality of life was evaluated by dermatology life quality index (DLQI). MetS was diagnosed according to Adult Treatment Panel III. Psoriatic patients presented smaller PhA (p < 0.001) and higher prevalence MetS compared with controls. The PhA was significantly associated with number of parameters of MetS in both groups (p < 0.001). After adjusting for BMI, this association remained significant in psoriatic patients only (p < 0.001). Among psoriatic patients, the PhA was the major index value for the diagnosis of MetS (OR 5.87, 95 % CI 5.07–6.79) and was inversely associated with both PASI score and DLQI, independently of BMI (p < 0.001). At multiple regression analysis, the PhA well predicted the PASI score and DLQI. Based on ROC curves, the most sensitive and specific cutoffs of PhA to predict the highest PASI score and the lowest DQLI were ≤4.8° and ≤4.9°, respectively. We reported that psoriatic patients presented small PhAs, with a novel association between PhA, clinical severity, quality of life in psoriatic patients, and MetS. Further studies are required to validate the PhA’s prognostic ability in assessing the clinical severity and MetS in psoriatic patients.