Association Between Daily Dietary Eicosatetraenoic Acid Intake and the Lower Risk of Psoriasis in American Adults

The Association Between Psoriasis and Trace Element Serum Levels and Dietary Intake: Results from USA National Health and Nutrition Examination Survey 2011-2014

Objective

Psoriasis is a common chronic inflammatory disease. However, trace elements are essential to biochemical processes of the skin, it is suspected that the trace elements are vital in the pathogenesis of psoriasis. Our research is aimed to investigate the association between serum levels and dietary intake levels of selenium, zinc, and copper with psoriasis.

Methods

In this cross-sectional study, we utilized the National Health and Nutrition Examination Survey data from 2011 to 2014 to examine the association between psoriasis and serum concentration and dietary intake of trace elements including copper, zinc, and selenium in the US individuals. Our research combined two cycles and weighted the data. Student's t-tests and χ2 test were used. Subgroup analyses and interaction tests were conducted by IBM SPSS Statistics 22 and EmpowerStats.

Results

This study indicates that the population with psoriasis has a lower dose of dietary intake selenium than the controls, and risk analysis showed that the men with selenium daily intake >150 mcg/day have a decreasing risk for psoriasis compared to those with daily intaking selenium <75 mcg/day. However, there are no differences on daily intake of selenium, zinc, and copper and serum levels of Zinc and Copper between psoriasis and healthy controls. The current study showed that the psoriasis group was significantly older with a bigger waist circumference, a higher education level, a higher ratio of people with smoke every day, and a higher ratio of people in USA and being non-Hispanic White.

Conclusion

This cross-section study showed that a high selenium intake may benefit USA adults from psoriasis, especially for males. The social and cultural background and ethnic differences between the two groups influence the eating and living models, including the trace element intake. The national recommended dietary allowances (RDAs) might be considered to be modified with more reliable investigative clinical data and certain considering the social and cultural models.

Causality of unsaturated fatty acids and psoriasis a Mendelian randomization study

Background

Many observational studies have identified a link between unsaturated fatty acids and psoriasis. However, they contain reverse causality and confounding factors, and there is no definite causal study between unsaturated fatty acids and psoriasis.

Objectives

Analysis of causality between unsaturated fatty acids and psoriasis by Mendelian randomization.

Methods

We used IEU Open GWAS Project, omega-3 PUFA and omega-6 PUFA data from 114,999 subjects, MUFA data from 13,535 subjects, and psoriasis data from 4,510 cases and 212,242 controls were included. We employed the inverse-variance weighted (IVW) method as the primary analytical approach and four additional MR methods. Moreover, we performed heterogeneity and horizontal pleiotropy assessments using Cochrane's Q and MR-Egger intercept tests, respectively. Finally, we performed sensitivity analyses to enhance our findings' precision and veracity.

Results

IVW results showed no causal effect of omega-3 PUFA on psoriasis (p = 0.334; OR, 0.909; 95% CI, 0.748-1.104), omega-6 PUFA cause psoriasis (p = 0.046; OR, 1.174; 95% CI, 1.003-1.374), MUFA cause psoriasis (p = 0.032; OR, 1.218; 95% CI, 1.018-1.457), no causal effect of omega-3 PUFA in psoriasis (p = 0.695; OR, 0.989; 95% CI, 0.937-1.044), no causal effect of omega-6 PUFA in psoriasis (p = 0.643; OR, 1.013; 95% CI, 0.960-1.068), psoriasis is not causal to MUFA (p = 0.986; OR, 1.000; 95% CI, 0.949-1.055). Heterogeneity, horizontal pleiotropy, and sensitivity analyses showed reliable results.

Conclusion

We found that circulating omega-6 PUFA and MUFA cause psoriasis, while omega-3 PUFA do not. Treatments that lower circulating omega-6 PUFA and MUFA are effective in psoriasis. After a better understanding of fatty acid intake and circulation, the population can be advised to regulate their diet.

The Role of Lifestyle and Nutrition in Psoriasis: Current Status of Knowledge and Interventions

Extrinsic environmental factors, including patient lifestyle (alcohol intake, smoking, stress, sleep disturbances, and sedentary habit), diet and single nutrients intake may affect psoriasis clinical presentation, severity, and course. All English language articles dealing with psoriasis and lifestyle factors or diet gathered by an extensive PubMed search were carefully examined in order to explore their impact on the disease. Current authoritative knowledge confirms that low‐calories, Mediterranean, and protein restricted/vegetarian diets may be beneficial. Psoriatic patients are also recommended to engage regular physical activity, to avoid alcohol intake and to consume fish rich in omega‐3 polyunsaturated fatty acids, as well as fruit and vegetables. Prebiotics and probiotics may also provide potential benefit, whereas vitamin D supplementation and gluten‐free diet are useful in selected cases only. Changing of dietary and lifestyle habits alone does not replace conventional treatment, but must be considered as an adjuvant. Physicians may play a crucial role, by adequately acknowledging psoriatic patients on the advantages of proper lifestyle and diet habits as well as providing clues to reliable sources of dietary advice.

Dietary Intervention and Supplements in the Management of Psoriasis: Current Perspectives

Nutrition is a complex topic encompassing diet and a variety of supplements including vitamins, fish oil, herbal products, and probiotics. Patients with psoriasis display high interest in understanding the potential impact of nutritional modifications on their psoriasis. In this review, we examine the evidence for nutritional interventions in psoriasis and summarize important concepts. We found that certain diets, such as low-calorie diets for obese patients, gluten-free diets for patients with comorbid celiac disease, and the Mediterranean diet, may have benefits for psoriasis patients. Supplements in general do not show strong evidence of benefit, though more studies are required given the heterogeneity of these trials. Finally, the gut microbiome has drawn considerable interest in recent years, with specific probiotics showing promising results for psoriasis patients and warranting further exploration.

Alpha-Linolenic Acid Modulates T Cell Incorporation in a 3D Tissue-Engineered Psoriatic Skin Model

Psoriasis is an autoimmune skin disease with an increased number of leukocytes infiltrating the dermal and epidermal compartments compared with normal skin. N-3 polyunsaturated fatty acids (n-3 PUFAs) are frequently used in the clinic in order to attenuate the symptoms of psoriasis. For psoriatic patients, a supplementation of the diet with alpha-linolenic acid (ALA) reduces the activation of T cell signaling pathways, leading to a significant reduction in inflammatory cytokine secretion. However, the precise mechanism of action of n-3 PUFAs in psoriasis is still not understood. In the present study, we elucidated the bioaction of ALA on the adaptive immune component of psoriasis by using a psoriatic skin model produced with the addition of activated T cells. Healthy and psoriatic skin substitutes were produced according to the self-assembly method, using culture media supplemented with 10 μM of ALA. T cells were isolated from blood samples using a negative selection isolation method. ALA supplementation regulated the hyperproliferation and abnormal cell differentiation of psoriatic keratinocytes stimulated by T cells. Additionally, the exogenous ALA was correctly incorporated into the phospholipids of keratinocytes, which resulted in increased levels of ALA, eicosapentaenoic acid (EPA) and n-3 docosapentaenoic acid (n-3 DPA). The infiltration of T cells into the epidermis was reduced when ALA was added to the culture medium, and significant decreases in the levels of inflammatory cytokines and chemokines such as CXCL1, interleukin-6 (IL-6) and interleukin-8 (IL-8) were consequently measured in psoriatic substitutes supplemented with this n-3 PUFA. Altogether, our results showed that in this psoriatic skin model enriched with T cells, ALA exerted its beneficial effect by decreasing the quantities of inflammatory mediators released by T cells.