The Mediterranean diet, fish oil supplements and Rheumatoid arthritis outcomes: evidence from clinical trials

Unlocking the Power of the Mediterranean Diet: Two in One-Dual Benefits for Rheumatic and Thyroid Autoimmune Diseases

In recent years, autoimmune diseases are becoming more and more prevalent worldwide, with this rapid rise being influenced by environmental factors linked to lifestyle changes in modern societies. In this context, the role of diet has been the topic of extensive research as evidence has mounted that particular dietary patterns may contribute to or modulate autoimmunity. The present review specifically focuses on the Mediterranean diet (MD) as a whole dietary pattern, and on its peculiar components, such as n-3 polyunsaturated fatty acids (PUFAs), polyphenols and fiber. We explored their potential benefits in a spectrum of both systemic and organ-specific autoimmune disorders, including rheumatic diseases (like rheumatic arthritis and systemic lupus erythematosus), and thyroid diseases (like Hashimoto's thyroiditis), since they often occur in the same individuals. Here, we offer a comprehensive review about the influence of dietary factors on these autoimmune diseases and potential translation into therapeutic interventions, as an adjuvant therapeutic approach to improve autoimmunity-related outcomes.

Association Between Dietary Niacin Intake and Rheumatoid Arthritis in American Women: A Study Based on National Health and Nutrition Examination Survey Database

Objective

This study aimed to explore the association between dietary niacin intake and rheumatoid arthritis (RA) in American women through the National Health and Nutrition Examination Survey (NHANES) database.

Methods

A retrospective analysis was conducted based on NHANES 2003-2016 data. Dietary niacin intake was stratified using weighted quartiles and association of dietary niacin intake with RA was explored using weighted logistic regression models and restricted cubic splines (RCS). Subgroup analysis was conducted, adjusting for all confounding factors, and a likelihood ratio test was utilized to determine significant covariates for the interaction term. Stratified analysis was conducted on significant covariates to determine their impact on the association of dietary niacin intake with RA.

Results

Fourteen thousand five hundred and thirty-nine American women were selected according to inclusion and exclusion criteria, among whom 845 (4.4%) had RA. Compared with American women without RA, American women with RA had significantly lower dietary niacin intake (18.90 vs 21.22, P<0.001). Logistic regression models and RCS analysis reported a significant linear negative correlation between dietary niacin intake and prevalence of RA (Odds Ratio (OR) < 1, P < 0.05, P-non-linear >0.05). The interaction-term P-values showed that this association was significantly influenced by poverty income ratio (PIR), education level, Body Mass Index (BMI), and smoking (P for interaction < 0.05). Stratified analysis unveiled that this association was particularly significant in individuals aged ≥ 40 years (OR: 0.98, 95% Confidence Interval (CI): 0.97-0.99, P < 0.05), PIR > 3.5 (OR: 0.96, 95% CI: 0.93-0.99, P < 0.05), with a college education or higher (OR: 0.97, 95% CI: 0.94-0.99, P < 0.01), BMI ≥ 30kg/m² (OR: 0.98, 95% CI: 0.96-0.99, P < 0.05), non-smokers (OR: 0.97, 95% CI: 0.95-0.99, P < 0.01), or former smokers (OR: 0.95, 95% CI: 0.95-0.99, P < 0.05).

Conclusion

Increased dietary niacin intake was associated with a reduced prevalence of RA, especially in women aged ≥40, PIR > 3.5, with at least a college education, BMI ≥ 30kg/m², and currently non-smokers.

Association between the adherence to Mediterranean diet and depression in rheumatoid arthritis patients: a cross-sectional study from the NHANES database

BACKGROUND

Rheumatoid arthritis (RA) is a systemic autoimmune disease, and depression is a most frequent comorbid condition associated with RA. Studies have shown that inflammation plays a vital role in the pathophysiology of depression and RA. Mediterranean diet (MED) has been proved to be a healthy anti-inflammatory dietary pattern. This study aims to explore the association between the adherence to Mediterranean diet (aMED) and depression in RA patients.

METHODS

In this study, RA patients aged ≥ 20 years old were extracted from the National Health and Nutrition Examination Survey (NAHNES) database. Dietary intake information was obtained from 24-h dietary recall interview. Covariates included sociodemographic information, lifestyles, laboratory parameters, and the history of diseases and medications were included. The weighted univariable and multivariable logistic regression models were used to assess the association between aMED and depression. Subgroup analysis was conducted to further explore the association between MED components and depression.

RESULTS

Totally 1,148 patients were included, of whom 290 (25.26%) had depression. After adjusted all covariates, high aMED was associated with the lower odds of depression in RA patients (OR = 0.53, 95%CI: 0.29-0.97). Among MED components, higher consumption of vegetables (OR = 0.54, 95%CI: 0.34-0.84) and cereals (OR = 0.63, 95%CI: 0.39-0.99) contributed more to decrease the odds of depression.

CONCLUSION

Greater aMED may have potential benefits for improving mental health in RA patients. Future large-scale cohort studies are needed to explore the association between aMED and depression in RA patients.

Adherence to the Mediterranean diet is associated with a reduced DAS28 index among patients with rheumatoid arthritis: Case study from KRRD

BACKGROUND

Rheumatoid arthritis (RA) is a chronic, autoimmune disease that mostly affects the synovial joints. It has been hypothesized that dietary and other environmental and lifestyle factors contribute to the development of RA and its severity.

OBJECTIVE

The present study aims to measure the effect of the Mediterranean diet (MedDiet) on the disease activity scores (DAS28) among patients with RA.

METHODS

Adult patients who satisfied the American College of Rheumatology (ACR) classification criteria for RA from major hospitals in Kuwait were evaluated. A cross-sectional study conducted on 754 RA patients visits aged (21-79) years. Patients were evaluated using the DAS28. Patients' levels of adherence to the MedDiet are assessed using a validated 14-item Questionnaire (paper or web-based). The data was analyzed using both multivariate and univariate statistics. Multivariate logistic regression was used to analyze the statistical relationship between MedDiet and RA disease activity.

RESULTS

The finding suggests that a MedDiet can have a positive impact on DAS28 among patients with RA. In the DAS28 cohort (DAS28 < 3.2, DAS28 ≥ 3.2), several Mediterranean survey components showed statistically significant differences. Patients with a Mediterranean score ≤ 5 was more likely to have hazard effects for DAS28 than those with a Mediterranean score of ≥10 (HR = 0.17, CI [0.08-0.37], p < .001). The finding shows that, Mediterranean levels ≤5, on biologics treatment, CRP, and patient global assessment were significantly associated with overall survival. Additionally, the MedDiet was found to be a significant predictor of DAS28 in the random forest decision tree plot, along with tender, RF, and creatinine. MedDiet patients had a lower DAS28 score than others.

CONCLUSION

The findings suggest that optimal drug treatment and a restrictive diet can help to improve DAS28 score for patients with RA. More patients in the cohort DAS28 <3.2 used olive oil, servings of vegetables, fruits, and legumes. In contrast, more patients in the cohort DAS28 ≥ 3.2 consumed red meat, butter, sweetened or soft drinks, cakes, cookies, or biscuits, and tomato sauce.

Global Trends in Research of Pain-Gut-Microbiota Relationship and How Nutrition Can Modulate This Link

INTRODUCTION

The link between gut microbiota and chronic painful conditions has recently gained attention. Nutrition, as a common intervention in daily life and medical practice, is closely related to microbiota and pain. However, no published bibliometric reports have analyzed the scientific literature concerning the link.

METHODS AND RESULTS

We used bibliometrics to identify the characteristics of the global scientific output over the past 20 years. We also aimed to capture and describe how nutrition can modulate the abovementioned link. Relevant papers were searched in the Web of Science database. All necessary publication and citation data were acquired and exported to Bibliometrix for further analyses. The keywords mentioned were illustrated using visualization maps. In total, 1551 papers shed light on the relationship from 2003 to 2022. However, only 122 papers discussed how nutritional interventions can modulate this link. The citations and attention were concentrated on the gut microbiota, pain, and probiotics in terms of the pain-gut relationship. Nutritional status has gained attention in motor themes of a thematic map.

CONCLUSIONS

This bibliometric analysis was applied to identify the scientific literature linking gut microbiota, chronic painful conditions, and nutrition, revealing the popular research topics and authors, scientific institutions, countries, and journals in this field. This study enriches the evidence moving boundaries of microbiota medicine as a clinical medicine.

Nutrition and its role in prevention and management of rheumatoid arthritis

Accumulating research evidence suggests that nutrition might be implicated in the risk of development and in the management of autoimmune disease, including rheumatoid arthritis (RA), characterized by immune-inflammatory response. Nutrition can have direct roles through the provision of pro- or anti-inflammatory foods, and indirect roles through management of co-morbidity management. The review updates on the evidence relating RA risk and management with focus on specific foods such as fish and diets/dietary patterns such as the Mediterranean diet, fasting and elimination diets and oral nutritional supplements including omega-3 polyunsaturated fatty acids (PUFA). Evidence on herbs and spices, beverages, Vitamin D, and probiotics is also reviewed. Diet has been shown to improve disease activity through reducing inflammation and oxidation and through its beneficial effects on the gut microbiota. Based on the existing evidence, it is recommended that as an adjunct to medical treatment, nutrition therapy for RA should be based on an anti-inflammatory Mediterranean diet (MD) supplemented with at least twice a week consumption of oily fish and/or omega-3 PUFA supplements at 2 g/day. The need for rheumatologists to work more closely with registered dietitians in the management of patients particularly in supporting a well-balanced diet according to individual needs, is highlighted.

Dietary Fiber Intake Influences Changes in Ankylosing Spondylitis Disease Status

The objectives of this study were to characterize dietary fiber (DF) intake in patients with ankylosing spondylitis (AS), to assess whether DF intake affects disease activity in AS, and to investigate the effect of DF intake on disease activity in AS in the context of functional bowel disease (FBD) symptoms. We recruited 165 patients with AS and divided them into two groups according to whether they had a high DF intake > 25 g/d to investigate the characteristics of people with high DF intake. Some 72 of the 165 AS patients (43%) met the criteria for high DF intake, which was more common in patients with negative FBD symptoms (68%). Data analysis revealed that DF intake was negatively associated with AS disease activity and did not differ statistically significantly from FBD symptoms. Multivariate adjusted models were used to explore the effect of DF intake on AS disease activity. ASDAS-CRP and BASDAI were stable and negatively correlated across models in both groups with and without FBD symptoms. Thus, DF intake positively affected disease activity in patients with AS. ASDAS-CRP and BASDAI were negatively correlated with DF intake.

Olive Oil and Nuts in Rheumatoid Arthritis Disease Activity

Few observational studies investigated the relationship between single food groups and disease activity in rheumatoid arthritis (RA). Within a recent Italian cross-sectional study (365 patients, median age: 58.46 years, 78.63% females), we focused on two food groups, olive oil and nuts, representing vegetable sources of fatty acids. Disease activity was measured with Disease Activity Score on 28 joints based on C-reactive protein (DAS28-CRP) and the Simplified Disease Activity Index (SDAI). Robust linear and logistic regression models included tertile-based consumption categories of each food group and several confounders. Stratified analyses were performed by disease severity or duration. Higher consumption of both food groups exerted a favorable effect on disease activity, significant only for olive oil (Beta: -0.33, p-value: 0.03) in the linear regression on the overall sample. This favorable effect was stronger in the more severe or long-standing forms of RA (p-value for heterogeneity <0.05, especially for disease severity). Significant ORs were as low as ~0.30 for both food groups, strata (i.e., more severe and long-standing RA), and disease activity measures. Mean DAS28-CRP significantly decreased by ~0.70 for olive oil and ~0.55 for nuts in the two strata; mean SDAI significantly decreased by 3.30 or more for olive oil in the two strata. Globally, the beta coefficients doubled, and the ORs halved (in absolute values) for both food groups, reaching significance in 12 of the 16 available models fitted to the more severe or long-standing RA strata. More compromised forms of RA may benefit from increasing consumption of olive oil, olives, and nuts.

Perspectives of colon-specific drug delivery in the management of morning symptoms of rheumatoid arthritis

Rheumatoid arthritis is a chronic condition that is characterized by joint pain and inflammation. It is an autoimmune disorder in which the body tissues are erroneously attacked by the immune system of the host itself. It has been evident that rheumatoid arthritis symptoms follow a 24 h circadian rhythm and exhibit high thresholds of pain, functional disability, and stiffness predominantly early in the morning. Colon-specific drug delivery systems can be utilized in the formulations to be used in the treatment of rheumatoid arthritis. The colon-specific drug delivery system has shown promising results in the treatment of different diseases at the colonic site like Crohn's disease, ulcerative colitis, colon cancer, etc. The colon-specific drug delivery is capable of delivering the formulation at the predetermined location and predetermined time. The early morning symptoms of rheumatoid arthritis like pain and inflammation can be treated using the various approaches of the colon-specific drug delivery system because it will lead to patient compliance as the patient will not require administering the formulation immediately after waking up in the morning. This review also explains the immunological factors which may trigger rheumatoid arthritis in human beings. It further explores conventional approaches like pH-dependant, microorganisms-driven, pressure-controlled, and time-dependant formulations. By employing two or more conventional approaches given above the various novel approaches have been designed to eliminate the drawbacks of individual techniques.

Consumption of Saturated Fatty Acids-Rich Lard Benefits Recovery of Experimental Arthritis by Activating PPAR-γ

SCOPE

This study investigates the impacts of lard and related fatty acids intake on rheumatoid arthritis (RA) animal models.

METHOD AND RESULTS

Collagen-induced arthritis (CIA) and adjuvant-induced arthritis (AIA) are induced in SD rats and C57 BL/6 mice respectively, which are fed by lard-rich diet (LRD) for 42 days with intake restriction or not. AIA SD rats are treated by representative fatty acids for 30 days. Body weight, arthritis score, and metabolic profile are periodically recorded. Monocyte distribution, cytokine/metabolites levels, gene expression, and tissue damages are investigated by flow cytometry, ELISA, colorimetry, PCR, and histological methods. After being treated by fatty acids in vitro, THP-1 monocytes and the corresponding medium are collected for ELISA, PCR, immunoblotting, and reporter gene assays. Irrespective of intake amounts, LRD decreases inflammatory cytokines and inhibits glycolysis in all rheumatic rodents. Furthermore, it alters monocyte distribution and promotes PPAR-γ expression in AIA mice. Overall evidences show that both saturated (SF) and unsaturated fatty acids (USF) from lard can attenuate inflammation by activating PPAR-γ. Silencing PPAR-γ abrogates their anti-inflammatory effects in vitro. Besides, SF can stimulate TLR4/NF-κB pathway.

CONCLUSION

Lard consumption is beneficial for active inflammatory arthritis recovery. Even SF can activate PPAR-γ and consequently attenuate inflammation.

A high-fiber diet synergizes with Prevotella copri and exacerbates rheumatoid arthritis

Both preclinical and established rheumatoid arthritis (RA) patients display alterations in the gut microbiome. Prevotella spp. are preferentially enriched in a subset of RA patients. Here, we isolated a Prevotella strain, P. copri RA, from the feces of RA patients and showed that colonization of P. copri RA exacerbated arthritis in a collagen-induced arthritis (CIA) model. With the presence of P. copri RA colonization, a high-fiber diet exacerbated arthritis via microbial alterations and intestinal inflammation. Colonization of P. copri together with a high-fiber diet enabled the digestion of complex fiber, which led to the overproduction of organic acids, including fumarate, succinate and short-chain fatty acids. Succinate promoted proinflammatory responses in macrophages, and supplementation with succinate exacerbated arthritis in the CIA model. Our findings highlight the importance of dysbiosis when evaluating the effects of dietary interventions on RA pathogenesis and provide new insight into dietary interventions or microbiome modifications to improve RA management.

Fish consumption, omega-3 fatty acid intake, and risk of pain: the Seniors-ENRICA-1 cohort

BACKGROUND & AIMS

Omega-3 fatty acids have anti-inflammatory and analgesic (anti-nociceptive) actions. However, the relation of habitual omega-3 fatty acid intake and fish consumption - its main food source - with pain remains largely unknown. We examined the association of fish consumption and marine omega-3 fatty acid intake with pain incidence and worsening over 5 years among older adults.

METHODS

Data were taken from the Seniors - ENRICA-1 cohort, which included 950 individuals aged ≥60 years in Spain. Habitual fish consumption and marine omega-3 fatty acid intake during the previous year were assessed in 2008-2010 and 2012 with a validated diet history. Pain was assessed in 2012 and 2017 with a scale developed from the Survey on Chronic Pain in Europe, ranging from 0 (no pain) to 6 (highest pain), according to its severity, frequency, and number of locations. Analyses on pain incidence were conducted in the 524 participants free of pain at baseline, while those on pain worsening were performed in the overall cohort, and both were adjusted for sociodemographic variables, lifestyle, morbidity, and diet quality.

RESULTS

Higher oily fish consumption was associated with reduced pain incidence and worsening over 5 years [fully adjusted odds ratios (95% confidence interval) = 0.68 (0.50,0.94) and 0.70 (0.55,0.88) for every 25 g/day increment (1.5 servings/week), respectively]. Total and white fish consumption were not associated with pain. Higher marine omega-3 fatty acid intake was inversely associated with pain worsening [odds ratio (95% confidence interval) per 0.5 g/day increment = 0.83 (0.72,0.96)]. The corresponding associations for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were 0.53 (0.33,0.87) and 0.73 (0.57,0.94).

CONCLUSIONS

In this cohort of Spanish older adults, increased oily fish consumption was inversely associated with pain incidence and worsening over 5 years, while higher marine omega-3 fatty acid intake (and that of EPA and DHA) was linked to less pain worsening.

The ABC-associated Immunosenescence and Lifestyle Interventions in Autoimmune Disease

Aging-associated immune changes, termed immunosenescence, occur with impaired robust immune responses. This immune response is closely related to a greater risk of development of autoimmune disease (AID), which results in increased levels of autoantibodies and increased morbidity and mortality. In addition, lifestyle-related risk factors play a pivotal role in AID, which may be probable via senescence-related immune cell subsets. Age-associated B cell (ABC) subsets have been observed in those who have rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and multiple sclerosis (MS). Here, this review aims to highlight the mechanisms of ABCs with lifestyle interventions in AID, especially how immunosenescence affects the pathogenesis of AID and the future of aging-associated lifestyle interventions in immunosenescence of AID.

The effect of Omega-3 fatty acid supplementation in systemic lupus erythematosus patients: A systematic review

OBJECTIVE

Many rheumatologists are inundated with questions about what "natural remedies" and "anti-autoimmune diets" exist for decreasing Systemic Lupus Erythematosus (SLE) disease activity. Over the last three decades, there has been an abundance of data from several different trials about omega-3 fatty acids sourced from fish oil, but the findings have been contradictory. This review seeks to present this data so that evidence-based recommendations can be given to patients, supporting the use of an adjuvant regimen with their present immunosuppression.

METHODS

A literature search was conducted using the PubMed, Google Scholar, MEDLINE, and Scopus electronic databases to retrieve relevant articles for this review. Trials conducted on human subjects with SLE with full publications in English were included from 1 January 1980 to 1 April 2021. The impact of fish oil-derived omega-3 fatty acid supplementation on specific clinical features, the innate and adaptive immune response, biomarkers, and disease activity measures were assessed. The initial search yielded 7519 articles, but only 13 met our criteria and were eligible for this review.

RESULTS

Data from thirteen articles were assessed. Ten trials assessed disease activity as an outcome, with eight trials demonstrating an improvement in patients in the omega-3 fatty acid group as assessed by a validated clinical tool or individual patient criteria. There was a significant improvement in Systemic Lupus Activity Measure-Revised (SLAM-R) scores at week 12 (p = .009) and week 24 (p < .001). Additionally, a reduction of urinary 8-isoprostane, a non-invasive marker of disease activity, was observed. There was no treatment benefit seen with respect to renal parameters such as serum creatinine or 24-hour urine protein; or systemic parameters such as C3, C4, or anti-double stranded DNA (anti-dsDNA) levels regardless of the dose of the omega-3 LUPUS fatty acids or duration of the trial.

CONCLUSION

While there is conflicting evidence about the benefits of omega-3 fatty acid supplementation on SLE disease activity, specific measures have demonstrated benefits. Current data show that there is a potential benefit on disease activity as demonstrated by SLAM-R, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and British Isles Lupus Assessment Group (BILAG) scores and plasma membrane arachidonic acid composition and urinary 8-isoprostane levels, with minimal adverse events.

Can I Prevent Developing a Rheumatic and Musculoskeletal Disease Through Lifestyle Changes? A Focus on Nutrition

Accumulating evidence suggests that nutrition can reduce the risk of rheumatic and musculoskeletal disease and especially rheumatoid arthritis (RA) development. This effect may be achieved either directly or indirectly through the consumption of anti-inflammatory nutrients or the reduction of comorbidities, respectively. A pro-inflammatory diet increases RA risk while the Mediterranean diet and oily fish consumption providing anti-inflammatory omega-3 fatty acids both reduce risk. High sugar and salt consumption is also associated with increased RA risk. Therefore, the Mediterranean diet supplemented with dietary omega-3 fatty acids is recommended for individuals genetically susceptible to RA.

Improvement of Inflammation and Pain after Three Months' Exclusion Diet in Rheumatoid Arthritis Patients

Introduction: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease affecting the synovial joints and causing severe disability. Environmental and lifestyle factors, including diet, have been proposed to play a role in the onset and severity of RA. Dietary manipulation may help to manage the symptoms of RA by lowering inflammation and potentially decreasing pain. Methods: In 40 patients with long-standing RA with stable symptoms and treated with conventional (c-) and biological (b-) disease modifying anti-rheumatic drugs (DMARDs), the effect of a 3-month diet avoiding meat, gluten, and lactose (and all dairy products; privative diet) was evaluated in comparison with a control balanced diet including those foods. Both diets were designed to reduce weight since all patients were overweight or obese. Patients were randomly assigned to one of the diets, and RA was clinically assessed at Time 0 (T0), through the Visual Analogue Scale (VAS), for pain, and the Disease Activity Score of 28 joints (DAS 28) for RA activity. Patients were also administered the Short Form Health survey (SF-36) and the Health Assessment Questionnaire (HAQ). At T0, a blood sample was collected for laboratory tests and adipokines measurements, and anthropometric measurements were compared. These evaluations were repeated at the end of the 3 months’ dietary regimens. Results: A significant decrease in VAS and the improvement of the overall state of physical and mental health, assessed through SF-36, was observed in patients assigned to the privative diet. Both dietary regimens resulted in the improvement of quality of life compared to baseline values; however, the change was significant only for the privative diet. With either diet, patients showed significant decreases in body weight and body mass index, with a reduction in waist and hips circumference and lower basal glucose and circulating leptin levels. A privative diet was also able to significantly reduce systolic (p = 0.003) and diastolic (p = 0.025) arterial pressure. The number of circulating leukocytes and neutrophils, and the level of hs-C-Reactive Protein also decreased after 3 months of the meat-, lactose-, and gluten-free diet. Conclusions: Our results suggest that a privative diet can result in a better control of inflammation in RA patients under stable optimized drug treatment.

Treatment of rheumatoid arthritis by phototherapy: advances and perspectives

Rheumatoid arthritis (RA) is an inflammatory disease that is prevalent worldwide and seriously threatens human health. Though traditional drug therapy can alleviate RA symptoms and slow progression, high dosage and frequent administration would cause unfavorable side effects. Phototherapy including photodynamic therapy (PDT) and photothermal therapy (PTT) has demonstrated distinctive potential in RA treatment. Under light irradiation, phototherapy can convert light into heat, or generate ROS, to promote necrosis or apoptosis of RA inflammatory cells, thus reducing the concentration of related inflammatory factors and relieving the symptoms of RA. In this review, we will summarize the development in the application of phototherapy in the treatment of rheumatoid arthritis.

Mediterranean diet in axial spondyloarthritis: an observational study in an Italian monocentric cohort

Background

Little evidence is available about the impact of diet on disease activity of axial spondyloarthritis (axSpA). This study evaluated the impact of a 6-month nutritional advice based on the Mediterranean diet on the disease activity of axSpA.

Methods

We prospectively collected the information of a group of axSpA patients who were offered nutritional advice for a 6-month period, who were compared to axSpA patients followed at the same center who were not on a specific diet. A nutritionist gave suggestions for dietary modification at baseline and thereafter every 2 months until month 6. Adherence to the Mediterranean diet was evaluated with the PREDIMED questionnaire ranging from 0 (no adherence) to 10 (optimal adherence); disease activity was evaluated with ASDAS-CRP. A multivariable regression analysis was conducted to identify independent predictors of PREDIMED and of ASDAS-CRP improvement (improvement ≥ 20% of each score).

Results

A total of 161 patients were included: 81 receiving nutritional advice and 80 controls; 47 in the nutritional group and 63 controls had complete information until month 6. Overall, 40 (36.4%) were females, the mean age was 51.7 ± 1.3 years, and 58 (52.7%) were affected with psoriasis. No relevant change of anthropometric or laboratory measures was observed in either group. Adherence to the Mediterranean diet was moderate (PREDIMED score 6.7 ± 1.8 at baseline; 7.6 ± 2.1 at month 6) and improved more in the nutritional group compared to controls (p = 0.020). Predictors of a PREDIMED improvement ≥ 20% were receiving nutritional advice (OR 4.53, 1.36–15.1, p = 0.014), age (per 10-year increase OR 1.05, 1.02–1.68, p = 0.007), and BMI (OR 0.77, 0.63–0.9, p = 0.006). An ASDAS-CRP improvement ≥ 20% was more frequent in the nutritional group compared to controls (p = 0.020). A PREDIMED improvement ≥ 20% was associated with a ASDAS-CRP improvement ≥ 20% (OR 6.75,1.8–25.3, p = 0.005). Psoriasis and disease duration were negatively but not significantly associated to the ASDAS-CRP improvement.

Conclusions

Improving adherence to the Mediterranean diet may have a beneficial impact on the activity of axSpA. Patients with a lower BMI and older patients are less prone to modify their diet towards the Mediterranean diet following nutritional advice. Patients with psoriasis may have a limited benefit from dietary improvement.

Study registration

Protocol No. 52723, Padova Hospital Medical Ethical Committee (October 11, 2010).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02600-0.

Fast and Specific Screening of EPA/DHA-Enriched Phospholipids in Fish Oil Extracted from Different Species by HILIC-MS

Eicosapentaenoic acid- and docosahexaenoic acid-enriched phospholipids (PL_EPA/DHA) have versatile health-beneficial functions and can be well absorbed in the intestine. Herein, a precursor ion scan-driven hydrophilic interaction chromatography mass spectrometry (PreIS-HILIC-MS) method with the fatty acyl moieties of m/z 301.6 and 327.6 locked was established to specifically and selectively screen PL_EPA/DHA in different fish oil samples, including saury, grass carp, hairtail, and yellow croaker. Taking saury oil as an example, a total of 24 PL_EPA/DHA were successfully identified and quantified, including 20 PC_EPA/DHA and 4 PE_EPA/DHA. Finally, this method was validated in terms of sensitivity (limit of detection ≤ 4.15 μg·mL^-1), linearity (≥0.9979), precision (RSD_intraday ≤ 4.65%), and recovery (≥78.6%). The performance of the PreIS-HILIC-MS method was also compared with that of the traditional full-scan mode, and the former demonstrated its unique superiority in targeted screening of PL_EPA/DHA in fish oils.

Perspective: The Saturated Fat-Unsaturated Oil Dilemma: Relations of Dietary Fatty Acids and Serum Cholesterol, Atherosclerosis, Inflammation, Cancer, and All-Cause Mortality

PUFAs are known to regulate cholesterol synthesis and cellular uptake by multiple mechanisms that do not involve SFAs. Polymorphisms in any of the numerous proteins involved in cholesterol homeostasis, as a result of genetic variation, could lead to higher or lower serum cholesterol. PUFAs are susceptible to lipid peroxidation, which can lead to oxidative stress, inflammation, atherosclerosis, cancer, and disorders associated with inflammation, such as insulin resistance, arthritis, and numerous inflammatory syndromes. Eicosanoids from arachidonic acid are among the most powerful mediators that initiate an immune response, and a wide range of PUFA metabolites regulate numerous physiological processes. There is a misconception that dietary SFAs can cause inflammation, although endogenous palmitic acid is converted to ceramides and other cell constituents involved in an inflammatory response after it is initiated by lipid mediators derived from PUFAs. This article will discuss the many misconceptions regarding how dietary lipids regulate serum cholesterol, the fact that all-cause death rate is higher in humans with low compared with normal or moderately elevated serum total cholesterol, the numerous adverse effects of increasing dietary PUFAs or carbohydrate relative to SFAs, as well as metabolic conversion of PUFAs to SFAs and MUFAs as a protective mechanism. Consequently, dietary saturated fats seem to be less harmful than the proposed alternatives.

Rheumatoid arthritis and dietary interventions: systematic review of clinical trials

CONTEXT

The impact of various dietary interventions on rheumatoid arthritis (RA), characterized by immune-inflammatory response, has been subject to increased attention.

OBJECTIVE

A systematic review was conducted to update the current knowledge on the effects of nutritional, dietary supplement, and fasting interventions on RA outcomes.

DATA SOURCES

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, with prespecification of all methods, Medline and Embase were systematically searched for relevant articles.

DATA EXTRACTION

Data were extracted by 2 independent reviewers.

RESULTS

A total of 70 human studies were identified. Administration of omega-3 polyunsaturated fatty acids at high doses resulted in a reduction in RA disease activity and a lower failure rate of pharmacotherapy. Vitamin D supplementation and dietary sodium restriction were beneficial on some RA outcomes. Fasting resulted in significant but transient subjective improvements. While the Mediterranean diet demonstrated improvements in some RA disease activity measures, outcomes from vegetarian, elimination, peptide, or elemental diets suggested that responses are very individualized.

CONCLUSION

Some dietary approaches may improve RA symptoms and thus it is recommended that nutrition should be routinely addressed.

Fabrication, characterization and properties of DHA-loaded nanoparticles based on zein and PLGA

This study focused on the feasibility of delivering docosahexaenoic acid (DHA) via zein/ Poly(lactic-co-glycolic) acid stabilized nanoparticles (ZPDNPs). ZPDNPs with good encapsulation efficiency, water solubility, and chemical instability were prepared by the antisolvent precipitation method. The structure and interaction force of ZPDNPs was evaluated using transmission electron microscopy, circular dichroism, X-ray powder diffraction, and FTIR. The stabilities of ZPDNPs for heating, pH, NaCl aqueous solution were also investigated. The results showed that ZPDNPs can improve the water solubility (750-fold), salt tolerance, and heat-resistant processing stability of DHA. The ZPDNPs had high encapsulation efficiency (84.6%) and stability after 35 days of storage. The simulated digestion of the gastrointestinal tract can change particle size, interface potential, and aggregation state of different DHA nanoparticles. The bioavailability of ZPDNPs was 4.2 ~ 5.6-folds higher than free DHA. Overall, a useful method for ZPDNPs formulation was developed for the delivery of DHA.

A Review on Rheumatoid Arthritis Interventions and Current Developments

Rheumatoid arthritis is a chronic autoimmune disorder characterized by inflammation, swelling, and joint destruction primarily affecting the peripheral joints. In recent years, RA has become an alarming concern affecting more than 1.5% of the population worldwide. The majority of the drugs in clinical trials for rheumatoid arthritis are immunomodulatory. The development of novel drugs for RA is impending and scientists are exploring new strategies through various innovative approaches for RA drug development. Treat-to-target and window of opportunity hypothesis are the new approaches that are used to treat, improve outcomes, and prevent long-term use of ineffective therapy, respectively. Novel therapeutic agents (e.g. GM-CSF inhibitors, Matrix metalloproteinase inhibitors) and delivery systems (e.g., Liposomes, Superparamagnetic iron oxide nano particles (SPIONs)) are under investigation for more target based therapy with reduced side effects and toxicity. The new drug discovery and repositioning of previously FDA-approved drugs are also being considered for chronic inflammatory disorder. The review encompasses a vast array of information, including genetics, etiology, clinical symptoms, current treatment, and newer therapeutics approaches, focused on the development of RA interventions. The introduction of the bioinformatics-based approach in RA has also been significantly discussed in the review. This review provides a general understanding of the challenges and uncertainties in the treatment of RA and summarizes the evolving scenario as well as innovative approaches taken into consideration for drug development in rheumatoid arthritis.

Nutraceuticals against Oxidative Stress in Autoimmune Disorders

Antioxidant mechanisms are constituted of enzymes, endogenous, and non-enzymatic, exogenous, which have the role of counterbalancing oxidative stress. Intake of these compounds occurs in the diet. Vegetables, plants, and fruits contain a wide range of alkaloids, polyphenols, and terpenoids which are called "phytochemicals". Most of these substances are responsible for the positive properties of fruits and vegetables, which are an essential part of a healthy life with roles in ameliorating chronic illnesses and favoring longevity. Nutraceuticals are substances contained in a food or fragment of it influencing health with positive effects on health helping in precenting or treating disorders. We conducted a review illustrating the principal applications of nutraceuticals in autoimmune disorders. Literature reported several studies about exogenous dietary antioxidant supplementation in diverse autoimmune diseases such as rheumatoid arthritis, lupus, diabetes, and multiple sclerosis. In these pathologies, promising results were obtained in some cases. Positive outcomes were generally associated with a reduction of oxidative stress parameters and a boost to antioxidant systems, and sometimes with anti-inflammatory effects. The administration of exogenous substances through food derivates or dietary supplements following scientific standardization was demonstrated to be effective. Further bias-free and extended studies should be conducted that include ever-increasing oxidative stress biomarkers.

Dietary Quality Associated with Self-Reported Diabetes, Osteoarthritis, and Rheumatoid Arthritis among Younger and Older US Adults: A Cross-Sectional Study Using NHANES 2011-2016

Background: To date, few studies have compared the dietary quality of US adults with diabetes mellitus (DM), osteoarthritis (OA), and rheumatoid arthritis (RA) by age groups. Methods: This study used cross-sectional data from adult participants from National Health and Nutrition Examination Survey 2011–2016 to identify dietary quality measured by Healthy Eating Index (HEI)-2015 total and component scores and self-reported disease status for DM, OA, and RA. Associations between the disease status and HEI-2015 total/component scores among younger adults aged 20–59 years (n = 7988) and older adults aged 60 years and older (n = 3780) were examined using logistic regression models. These accounted for the complex survey design and were adjusted for self-reported disease status, sex, race/ethnicity, education levels, income status, weight status, physical activity levels, and smoking status. Results: Among younger adults, 7% had DM, 7% had OA, and 3% had RA. Among older adults, 20% had DM, 32% had OA, and 6% had RA. Moderate added sugar intake was associated with diabetes in all adults. Excess sodium intake was associated with DM among younger adults. Inadequate seafood and plant protein intake was associated with RA among younger adults, while a poor overall dietary pattern was associated with RA among older adults. Conclusions: The dietary quality of US adults varied by self-reported DM, OA, and RA status, and each varied by age group.

A Posteriori Dietary Patterns and Rheumatoid Arthritis Disease Activity: A Beneficial Role of Vegetable and Animal Unsaturated Fatty Acids

To our knowledge, no studies have investigated the relationship between a posteriori dietary patterns (DPs)-representing current dietary behavior-and disease activity in patients with rheumatoid arthritis (RA). We analyzed data from a recent Italian cross-sectional study including 365 RA patients (median age: 58.46 years, 78.63% females). Prevalent DPs were identified through principal component factor analysis on 33 nutrients. RA activity was measured according to the Disease Activity Score on 28 joints (DAS28) and the Simplified Disease Activity Index (SDAI). Single DPs were related to disease activity through linear and logistic regression models, adjusted for the remaining DPs and confounders. We identified five DPs (~80% variance explained). Among them, Vegetable unsaturated fatty acids (VUFA) and Animal unsaturated fatty acids (AUFA) DPs were inversely related to DAS28 in the overall analysis, and in the more severe or long-standing RA subgroups; the highest score reductions (VUFA: 0.81, AUFA: 0.71) were reached for the long-standing RA. The SDAI was inversely related with these DPs in subgroups only. This Italian study shows that scoring high on DPs based on unsaturated fats from either source provides independent beneficial effects of clinical relevance on RA disease activity, thus strengthening evidence on the topic.

A Comparison of Gene Expression Changes in the Blood of Individuals Consuming Diets Supplemented with Olives, Nuts or Long-Chain Omega-3 Fatty Acids

Background: The Mediterranean diet, which is rich in olive oil, nuts, and fish, is considered healthy and may reduce the risk of chronic diseases. Methods: Here, we compared the transcriptome from the blood of subjects with diets supplemented with olives, nuts, or long-chain omega-3 fatty acids and identified the genes differentially expressed. The dietary genes obtained were subjected to network analysis to determine the main pathways, as well as the transcription factors and microRNA interaction networks to elucidate their regulation. Finally, a gene-associated disease interaction network was performed. Results: We identified several genes whose expression is altered after the intake of components of the Mediterranean diets compared to controls. These genes were associated with infection and inflammation. Transcription factors and miRNAs were identified as potential regulators of the dietary genes. Interestingly, caspase 1 and sialophorin are differentially expressed in the opposite direction after the intake of supplements compared to Alzheimer’s disease patients. In addition, ten transcription factors were identified that regulated gene expression in supplemented diets, mild cognitive impairment, and Alzheimer’s disease. Conclusions: We identified genes whose expression is altered after the intake of the supplements as well as the transcription factors and miRNAs involved in their regulation. These genes are associated with schizophrenia, neoplasms, and rheumatic arthritis, suggesting that the Mediterranean diet may be beneficial in reducing these diseases. In addition, the results suggest that the Mediterranean diet may also be beneficial in reducing the risk of dementia.

Disease Activity, Functional Ability and Nutritional Status in Patients with Rheumatoid Arthritis: An Observational Study in Greece

AIM

The aim of the present pilot study was to assess differences in the nutritional status, Mediterranean diet (MD) adherence, and functional ability among patients with rheumatoid arthritis (RA), according to disease activity.

METHODS

A total of 48 patients with RA, outpatients of a hospital in Athens, Greece were recruited. Disease activity was evaluated with DAS28, functional status with the Health Assessment Questionnaire (HAQ), MD adherence with the MedDietScore and malnutrition with the patient-generated subjective global assessment (PG-SGA).

RESULTS

A relationship was noted between DAS28 and HAQ, indicating a reduced functional status with increased RA activity. Although MD adherence differed between DAS28 categories, no specific differences were noted in the PG-SGA or the MedDietScore in the post-hoc analyses. According to the PG-SGA, no need for nutritional intervention was noted among participants.

CONCLUSIONS

The origin of the participants might have reduced the differences between MD adherence and DAS28. In parallel, the PG-SGA does not appear sensitive in detecting muscle-related malnutrition among patients with RA.

Nutritional modulation of leptin expression and leptin action in obesity and obesity-associated complications

In obesity, an elevated accumulation and dysregulation of adipose tissue, due to an imbalance between energy intake and energy expenditure, usually coexists with the loss of responsiveness to leptin in central nervous system, and subsequently with hyperleptinemia. Leptin, a peptide hormone mainly produced by white adipose tissue, regulates energy homeostasis by stimulating energy expenditure and inhibiting food intake. Human obesity is characterized by increased plasma leptin levels, which have been related with different obesity-associated complications, such as chronic inflammatory state (risk factor for diabetes, cardiovascular and autoimmune diseases), as well as infertility and different types of cancer. Besides, leptin is also produced by placenta, and high leptin levels during pregnancy may be related with some pathological conditions such as gestational diabetes. This review focuses on the current insights and emerging concepts on potentially valuable nutrients and food components that may modulate leptin metabolism. Notably, several dietary food components, such as phenols, peptides, and vitamins, are able to decrease inflammation and improve leptin sensitivity by up- or down-regulation of leptin signaling molecules. On the other hand, some food components, such as saturated fatty acids may worsen chronic inflammation increasing the risk for pathological complications. Future research into nutritional mechanisms that restore leptin metabolism and signals of energy homeostasis may inspire new treatment options for obesity-related disorders.

Diet as a Modulator of Intestinal Microbiota in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic immune-driven inflammatory disease characterised by synovial inflammation, leading to progressive cartilage and bone destruction, impacting patients' functional capacity and quality of life. Patients with RA have significant differences in gut microbiota composition when compared to controls. Intestinal dysbiosis influences the intestinal barrier strength, integrity and function, and diet is considered the main environmental factor impacting gut microbiota. Over the last few years, researchers have focused on the influence of single components of the diet in the modulation of intestinal microbiota in RA rather than whole dietary patterns. In this review, we focus on how the Mediterranean diet (MD), a whole dietary pattern, could possibly act as an adjuvant therapeutic approach, modulating intestinal microbiota and intestinal barrier function in order to improve RA-related outcomes. We also review the potential effects of particular components of the MD, such as n-3 polyunsaturated fatty acids (PUFAs), polyphenols and fibre.

Beverages in Rheumatoid Arthritis: What to Prefer or to Avoid

Background: The role of nutrition in the pathogenesis of rheumatic diseases, including rheumatoid arthritis (RA), has gained increasing attention in recent years. A growing number of studies have focussed on the diverse nutritional contents of beverages, and their possible role in the development and progression of RA. Main body: We aimed to summarise the current knowledge on the role of a range of beverages in the context of RA. Beverages have a key role within the mosaic of autoimmunity in RA and potential to alter the microbiome, leading to downstream effects on inflammatory pathways. The molecular contents of beverages, including coffee, tea, and wine, have similarly been found to interfere with immune signalling pathways, some beneficial for disease progression and others less so. Finally, we consider beverages in the context of wider dietary patterns, and how this growing body of evidence may be harnessed by the multidisciplinary team in patient management. Conclusions: While there is increasing work focussing on the role of beverages in RA, integration of discussions around diet and lifestyle in our management of patients remains sparse. Nutrition in RA remains a controversial topic, but future studies, especially on the role of beverages, are likely to shed further light on this in coming years.

The Relevance of Selenium Status in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that can cause joint damage. Among the environmental risk factors, diet plays an important role because it can aggravate or attenuate inflammation. Selenium (Se) is considered an essential trace element since it is a structural component of antioxidant enzymes; however, its concentration can be affected by diet, drugs and genetic polymorphisms. Studies have reported that RA patients have a deficient diet in some food groups that is associated with parameters of disease activity. Furthermore, it has been shown that there is an alteration in serum Se levels in this population. Although some clinical trials have been conducted in the past to analyze the effect of Se supplementation in RA, no significant results were obtained. Contrastingly, experimental studies that have evaluated the effect of novel Se nanoparticles in RA-induced models have shown promising results on the restoration of antioxidant enzyme levels. In particular, glutathione peroxidase (GPx) is an important selenoprotein that could have a modulating effect on inflammation in RA. Considering that RA patients present an inflammatory and oxidative state, the aim of this review is to give an overview of the current knowledge about the relevance of Se status in RA.

Adherence to Mediterranean diet and patient perception of rheumatoid arthritis

OBJECTIVE

To evaluate the association between the adherence to Mediterranean diet (MD) and disease impact, activity, and comorbidities in patients with rheumatoid arthritis (RA).

DESIGN

Consecutive patients with RA were enrolled in this cross-sectional study. For each patient, Disease Activity Score on 28 joints (DAS28), Simple Disease Activity Index (SDAI), RA Impact of Disease (RAID), Health Assessment Questionnaire (HAQ), patient global assessment (PGA) and general health (GH) and a self-reported questionnaire called MD score were recorded.

RESULTS

205 RA patients (median age 53 years, female 80.49 %) were enrolled. An association between MD score and HAQ (p-value = 0.033), PGA and GH (p-value 0.023 both) was observed. RAID total score had a statistically significant negative relationship with MD score (p-value = 0.016). A statistically significant negative association was found for pain (p-value = 0.025), functional disability (p-value<0.001), sleep (p-value = 0.041), physical well-being (p-value = 0.027) and coping (p-value = 0.008). Multiple regression analysis to evaluate the relationship between significant RAID items and MD score did not show any statistical significance as all items are strongly related to each other. A negative trend, although not statistically significant was found for DAS28 and SDAI. The only comorbidity associated with MD score was arterial hypertension (OR = 0.94).

CONCLUSIONS

In this Italian RA cohort, the adherence to MD was significantly associated with a better RAID, PGA and GH, but higher MD score was not significantly associated with lower disease activity. Our study suggests an overall potential beneficial effect of MD in RA patients.

Overview of the Associations Between Cancer and Rheumatic Disease

People living with rheumatic diseases frequently encounter cancer, either as a potential harm of antirheumatic therapies or as a comorbidity that alters the conversation about management. This article provides a general overview of the issues related to cancer and rheumatic disease and serves as a springboard for the remaining chapters in this issue. Several topics are reviewed, including epidemiology, bidirectional causal pathways, and issues related to medications. Although uncertainties remain, the issue of cancer is of great importance to patients with rheumatic diseases, and an individualized, person-centered approach to assessment and management is necessary.

Modifiable Lifestyle Factors Associated With Response to Treatment in Early Rheumatoid Arthritis

Objective

We aimed to evaluate the associations between response to algorithm‐directed treat‐to‐target conventional synthetic disease‐modifying antirheumatic drug therapy and potentially modifiable lifestyle factors, including dietary fish oil supplementation, body mass index (BMI), and smoking history in a rheumatoid arthritis (RA) inception cohort.

Methods

Patients with RA with a duration of less than 12 months were reviewed every 3 to 6 weeks to adjust therapy according to disease response. All patients received advice to take fish oil supplements, and omega‐3 status was measured as plasma levels of eicosapentaenoic acid (EPA). Lifestyle factors and other variables potentially prognostic for 28‐joint Disease Activity Score (DAS28) remission and DAS28 low disease activity (LDA) at the 12‐month visit were included in multivariable logistic regression models.

Results

Of 300 participants, 57.7% reached DAS28 LDA, and 43.7% were in DAS28 remission at 1 year. Increase in plasma EPA was associated with an increase in the odds of being in LDA (adjusted odds ratio [OR] = 1.27; P < 0.0001) and remission (adjusted OR = 1.21; P < 0.001). There was some evidence that the effect of BMI on LDA might be modified by smoking history. An increase in BMI was associated with a decrease in the odds of being in LDA in current and former smokers but had no impact on LDA in patients who had never smoked. There were no meaningful associations between BMI or smoking history and remission.

Conclusion

Omega‐3 status, BMI, and smoking history are potential predictors of outcome in early RA. The possibility of an effect modification by smoking on the predictive value of BMI merits further investigation.

Fish oil supplementation and maintaining muscle mass in chronic disease: state of the evidence

PURPOSE OF REVIEW

Providing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the form of fish oils, to benefit muscle is an emerging area of interest. The aim of this work was to evaluate the current literature that has assessed muscle mass as an outcome during a fish oil intervention in any chronic disease.

RECENT FINDINGS

The vast majority of studies published in the last 3 years (12 of 15) have been conducted in the oncological setting, in patients undergoing treatment for cancers of the gastrointestinal tract, breast, head and neck, lung, cervix, and hematological cancers. Three studies were conducted in patients with chronic obstructive pulmonary disease (COPD). Fish oil was provided as part of nutrient mixtures in 12 studies and as capsules in three studies.

SUMMARY

Overall, the evidence for an effect of fish oil supplementation on muscle mass in patients with cancer undergoing treatment and in COPD remains unequivocal and reveals limited new knowledge in the area of fish oil supplementation in the cancer setting. Recent literature continues to provide mixed evidence on the efficacy of fish oil on muscle mass and function. The present review highlights challenges in comparing and interpreting current studies aimed at testing fish oil supplementation for muscle health.

Genome-Wide Association Study for Serum Omega-3 and Omega-6 Polyunsaturated Fatty Acids: Exploratory Analysis of the Sex-Specific Effects and Dietary Modulation in Mediterranean Subjects with Metabolic Syndrome

Many early studies presented beneficial effects of polyunsaturated fatty acids (PUFA) on cardiovascular risk factors and disease. However, results from recent meta-analyses indicate that this effect would be very low or nil. One of the factors that may contribute to the inconsistency of the results is that, in most studies, genetic factors have not been taken into consideration. It is known that fatty acid desaturase (FADS) gene cluster in chromosome 11 is a very important determinant of plasma PUFA, and that the prevalence of the single nucleotide polymorphisms (SNPs) varies greatly between populations and may constitute a bias in meta-analyses. Previous genome-wide association studies (GWAS) have been carried out in other populations and none of them have investigated sex and Mediterranean dietary pattern interactions at the genome-wide level. Our aims were to undertake a GWAS to discover the genes most associated with serum PUFA concentrations (omega-3, omega-6, and some fatty acids) in a scarcely studied Mediterranean population with metabolic syndrome, and to explore sex and adherence to Mediterranean diet (MedDiet) interactions at the genome-wide level. Serum PUFA were determined by NMR spectroscopy. We found strong robust associations between various SNPs in the FADS cluster and omega-3 concentrations (top-ranked in the adjusted model: FADS1-rs174547, p = 3.34 × 10-14; FADS1-rs174550, p = 5.35 × 10-14; FADS2-rs1535, p = 5.85 × 10-14; FADS1-rs174546, p = 6.72 × 10-14; FADS2-rs174546, p = 9.75 × 10-14; FADS2- rs174576, p = 1.17 × 10-13; FADS2-rs174577, p = 1.12 × 10-12, among others). We also detected a genome-wide significant association with other genes in chromosome 11: MYRF (myelin regulatory factor)-rs174535, p = 1.49 × 10-12; TMEM258 (transmembrane protein 258)-rs102275, p = 2.43 × 10-12; FEN1 (flap structure-specific endonuclease 1)-rs174538, p = 1.96 × 10-11). Similar genome-wide statistically significant results were found for docosahexaenoic fatty acid (DHA). However, no such associations were detected for omega-6 PUFAs or linoleic acid (LA). For total PUFA, we observed a consistent gene*sex interaction with the DNTTIP2 (deoxynucleotidyl transferase terminal interacting protein 2)-rs3747965 p = 1.36 × 10-8. For adherence to MedDiet, we obtained a relevant interaction with the ME1 (malic enzyme 1) gene (a gene strongly regulated by fat) in determining serum omega-3. The top-ranked SNP for this interaction was ME1-rs3798890 (p = 2.15 × 10-7). In the regional-wide association study, specifically focused on the FADS1/FASD2/FADS3 and ELOVL (fatty acid elongase) 2/ELOVL 5 regions, we detected several statistically significant associations at p < 0.05. In conclusion, our results confirm a robust role of the FADS cluster on serum PUFA in this population, but the associations vary depending on the PUFA. Moreover, the detection of some sex and diet interactions underlines the need for these associations/interactions to be studied in all specific populations so as to better understand the complex metabolism of PUFA.

Interaction between food antigens and the immune system: Association with autoimmune disorders

It has been shown that environmental factors such as infections, chemicals, and diet play a major role in autoimmune diseases; however, relatively little attention has been given to food components as the most prevalent modifiers of these afflictions. This review summarizes the current body of knowledge related to different mechanisms and associations between food proteins/peptides and autoimmune disorders. The primary factor controlling food-related immune reactions is the oral tolerance mechanism. The failure of oral tolerance triggers immune reactivity against dietary antigens, which may initiate or exacerbate autoimmune disease when the food antigen shares homology with human tissue antigens. Because the conformational fit between food antigens and a host's self-determinants has been determined for only a few food proteins, we examined evidence related to the reaction of affinity-purified disease-specific antibody with different food antigens. We also studied the reaction of monoclonal or polyclonal tissue-specific antibodies with various food antigens and the reaction of food-specific antibodies with human tissue antigens. Examining the assembled information, we postulated that chemical modification of food proteins by different toxicants in food may result in immune reaction against modified food proteins that cross-react with tissue antigens, resulting in autoimmune reactivity. Because we are what our microbiome eats, food can change the gut commensals, and toxins can breach the gut barrier, penetrating into different organs where they can initiate autoimmune response. Conversely, there are also foods and supplements that help maintain oral tolerance and microbiome homeostasis. Understanding the potential link between specific food consumption and autoimmunity in humans may lay the foundation for further research about the proper diet in the prevention of autoimmune diseases.

Factors Associated With Low Lean Mass in Early Rheumatoid Arthritis: A Cross- Sectional Study

Background and Objectives: The aim of the study was to evaluate body composition (BC) of rheumatoid arthritis (RA) patients at disease onset compared to population controls focusing on the associations between low lean mass and disease specific parameters, nutritional factors and physical activity. Materials and Methods: 91 patients with early rheumatoid arthritis (ERA) (72% female) and 328 control subjects (54% female) were studied. BC- lean and fat mass parameters were measured with a Lunar Prodigy Dual Energy X-Ray Absorptiometry (DXA) machine. The prevalence, age and gender adjusted odds ratios of having low lean mass and overfat, associations between nutrition, physical activity, and ERA disease specific parameters and the presence of low lean mass were evaluated. Results: We found that the BC of patients with recent onset RA differs from control subjects-ERA patients had a higher mean body fat percentage (BFP) and lower appendicular lean mass (ALM). 41.8% of the ERA patients and 19.8% of the controls were classified as having low lean mass adjusted OR 3.3 (95% C.I. 1.9-5.5, p < 0.001). 68.1% of the ERA subjects and 47.3% of the controls were overfat (adjusted OR 1.9 (95% C.I. 1.1-3.3, p = 0.02)) and the adjusted odds of having both low lean mass and overfat were 4.4 times higher (26.4% vs. 7.0% 95% C.I. 2.3-8.4, p < 0.001) among the ERA group. Higher ESR (OR 1.03, C.I.1.002-1.051, p = 0.03), CRP (OR 1.03, C.I. 1.002-1.061, p = 0.04), lower protein intake (OR 0.98 C.I. 0.96-0.99, p = 0.04), corticosteroid usage (OR 3.71 C.I. 1.4-9.9, p < 0.01) and lower quality of life (higher HAQ score OR 2.41 C.I. 1.24-4.65, p < 0.01) were associated with having low lean mass in the ERA group (adjusted to age and gender). Conclusions: Patients with early RA have lower appendicular lean mass and higher body fat percentage compared to healthy controls. Loss of lean mass in early RA is associated with elevated inflammatory markers inducing catabolism, lower protein intake and also with GCS treatment.

Mediterranean diet and Psoriatic Arthritis activity: a multicenter cross-sectional study

Diet is a modifiable factor implicated in chronic systemic inflammation, and the mediterranean dietary pattern is considered to be a healthy model in terms of morbidity and mortality. The main aim of this study was to evaluate the adherence to the mediterranean diet in patients with Psoriatic Arthritis (PsA) and its impact on disease activity. A cross-sectional observational study was conducted in a cohort of 211 consecutive PsA patients. We evaluated PsA activity by disease activity index for PSoriatic Arthritis (DAPSA) and composite psoriatic disease activity index (CPDAI). The NCEP-ACT III criteria were used to identify subjects with MetS, and in each subject, we evaluated body mass index (BMI). A validated 14-item questionnaire for the assessment of adherence to the mediterranean diet (PREDIMED) was recorded for all the enrolled subjects. Patients showed a median age of 55 (48-62) and disease duration was 76 (36-120) months. 27.01% of patients were classified as having MetS. The median of the mediterranean diet score (MDS) was 7 (6-9). A moderate adherence to mediterranean diet was found in 66.35% of the entire cohort; 15.64% and 18.01% of the patients showed low- and high adherence to the dietary pattern, respectively. We found a negative association between DAPSA and adherence to mediterranean diet (B = - 3.291; 95% CI - 5.884 to - 0.698). DAPSA was positively associated with BMI (B = 0.332; 95% CI 0.047-0.618) and HAQ ( B = 2.176; 95% CI 0.984-3.368). Results from our study evidenced that in PsA patients, higher levels of disease activity as measured by DAPSA correlated with low adherence to mediterranean diet, suggesting potential benefit of antinflammatory properties of this dietary pattern.

Challenges in the treatment of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic inflammatory disease characterized by a heterogeneous clinical response to the different treatments. Some patients are difficult to treat and do not reach the treatment targets as clinical remission or low disease activity. Known negative prognostic factors, such as the presence of auto-antiantibodies and joint erosion, the presence of a genetic profile, comorbidities and extra-articular manifestations, pregnancy or a pregnancy wish may concur to the treatment failure. In this review we aimed at identify difficult to treat RA patients and define the optimal therapeutic and environmental targets. Genetic markers of severity such as HLA-DRB1, TRAF1, PSORS1C1 and microRNA 146a are differently associated with joint damage; other gene polymorphisms seem to be associated with response to biologic disease modifying anti-rheumatic drugs (bDMARDs). The presence of comorbidities and/or extra-articular manifestations may influence the therapeutic choice; overweight and obese patients are less responsive to TNF inhibitors. In this context the patient profiling can improve the clinical outcome. Targeting different pathways, molecules, and cells involved in the pathogenesis of RA may in part justify the lack response of some patients. An overview of the future therapeutic targets, including bDMARDs (inhibitors of IL-6, GM-CSF, matrix metalloproteinases, chemokines) and targeted synthetic DMARDs (filgotinib, ABT-494, pefacitinib, decernotinib), and environmental targets is addressed. Environmental factors, such as diet and cigarette smoke, may influence susceptibility to autoimmune diseases and interfere with inflammatory pathways. Mediterranean diet, low salt intake, cocoa, curcumin, and physical activity seem to show beneficial effects, however studies of dose finding, safety and efficacy in RA need to be performed.