Antioxidant intake, plasma antioxidants and oxidative stress in a randomized, controlled, parallel, Mediterranean dietary intervention study on patients with rheumatoid arthritis

Unraveling the intricate dance of the Mediterranean diet and gut microbiota in autoimmune resilience

The nutritional habits regulate the gut microbiota and increase risk of an autoimmune disease. Western diet is rich in sugars, meat, and poly-unsaturated fatty acids, which lead to dysbiosis of intestinal microbiota, disruption of gut epithelial barrier and chronic mucosal inflammation. In contrast, the Mediterranean Diet (MedDiet) is abundant in ω3 fatty acids, fruits, and vegetables, possessing anti-inflammatory properties that contribute to the restoration of gut eubiosis. Numerous studies have extensively examined the impact of MedDiet and its components on both health and various disease states. Additionally, specific investigations have explored the correlation between MedDiet, microbiota, and the risk of autoimmune diseases. Furthermore, the MedDiet has been linked to a reduced risk of cardiovascular diseases, playing a pivotal role in lowering mortality rates among individuals with autoimmune diseases and comorbidities. The aim of the present review is to specifically highlight current knowledge regarding possible interactions of MedDiet with the patterns of intestinal microbiota focusing on autoimmunity and a blueprint through dietary modulations for the prevention and management of disease's activity and progression.

Associations of cereal fiber intake with rheumatoid arthritis mediated by dietary inflammatory index: insights from NHANES 2011-2020

Rheumatoid Arthritis (RA) is an increasingly prevalent inflammatory disorder worldwide. Its complex etiology has recently brought dietary factors, particularly fiber intake, into focus as potential influencers. Our study investigates the intricate relationship between various sources of dietary fiber and RA, emphasizing the mediating role of the Dietary Inflammatory Index (DII). Leveraging data from the National Health and Nutrition Examination Survey spanning 2011 to 2020. We meticulously assessed dietary fiber intake through dual 24 h dietary recall interviews, while RA diagnoses were established based on comprehensive medical surveys. The relationships between fiber intake, RA prevalence, and DII mediation were analyzed using sophisticated multivariate logistic regression and mediation analysis. Among our study cohort, 7% were diagnosed with RA. We observed a notable inverse correlation between increased total fiber intake, particularly 5 g/day increments, and the incidence of RA, with cereal fiber intake emerging as the primary mitigating factor. Intriguingly, the DII played a significant role in mediating this association, especially regarding cereal fiber. Our findings reveal a significant association between higher cereal fiber consumption and a reduced prevalence of RA. Additionally, the DII stands out as a pivotal mediator in this relationship, highlighting dietary management's critical role in preventing and managing RA.

From reactive species to disease development: Effect of oxidants and antioxidants on the cellular biomarkers

The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an important role in inducing reactive stress (RS) and disease. The imbalance in the production and scavenging of free radicals and the induction of RS (oxidative, nitrosative, and halogenative) plays an essential role in the etiology of various chronic pathologies, such as cardiovascular diseases, diabetes, neurodegenerative diseases, and cancer. The implication of free radicals and reactive species injury in metabolic disturbances and the onset of many diseases have been accumulating for several decades, and are now accepted as a major cause of many chronic diseases. Exposure to elevated levels of free radicals can cause molecular structural impact on proteins, lipids, and DNA, as well as functional alteration of enzyme homeostasis, leading to aberrations in gene expression. Endogenous depletion of antioxidant enzymes can be mitigated using exogenous antioxidants. The current interest in the use of exogenous antioxidants as adjunctive agents for the treatment of human diseases allows a better understanding of these diseases, facilitating the development of new therapeutic agents with antioxidant activity to improve the treatment of various diseases. Here we examine the role that RS play in the initiation of disease and in the reactivity of free radicals and RS in organic and inorganic cellular components.

Oxidative Stress Mediated Therapy in Patients with Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this meta-analysis is to explore all the available literature to obtain updated data about the potential use of antioxidants in the treatment of rheumatoid arthritis (RA) and its ability to reduce disease progression and cardiovascular risk.

METHODS

This systematic review and meta-analysis was performed strictly in accordance with the PRISMA guidelines. English and Chinese databases were searched with a retrieval time up to March 2023. These databases included the PubMed, Embase, Medline Complete, Web of Sciences and Cochrane Collaboration, Wanfang, China National Knowledge Infrastructure, and VIP databases. This literature search was formulated by the two researchers independently. The search strategy consists of reading, collecting the literature, and conducting the preliminary screening. After that, they provide the final selection of the literature according to the inclusion criteria and data extraction. Also, for all studies, the risk bias was assessed to evaluate the quality of the included references. The content of the risk assessment of bias included the following criteria: random allocation method, allocation plan hiding, blind method, completeness of result data, and selectivity of reporting of results, as well as other biases. The main outcomes were clinical efficiency of antioxidant therapy (C-reactive protein, DAS28 score, HAQ, Number of tender joints, etc.) and oxidative stress indicators (catalase, superoxide dismutase, or total antioxidant capacity).

RESULTS

We observed, in most of the studies, the small or moderate effects of antioxidant treatment. The mean effect size is 0.525, and that means that moderate effects were observed in 30 selected RCTs. Also, this effect is confirmed in the 1652 patients with RA with the mean confidence interval of 0.276 (lower limit) and 0.983 (upper limit). Cohen coefficient was calculated at 0.05.

CONCLUSION

The existing evidence is that antioxidants can reduce systemic and local oxidative stress and can reduce damage as the main agent involved in autoimmune diseases such as rheumatoid arthritis.

Dietary patterns, uric acid levels, and hyperuricemia: a systematic review and meta-analysis

Background: Studies investigating the effects of dietary intake on serum uric acid (SUA) and hyperuricemia have yielded inconsistent results. Therefore, we conducted a meta-analysis to assess the associations between various dietary patterns and SUA levels as well as hyperuricemia. Methods: We searched PubMed, Web of Science, and EMBASE databases for relevant articles examining the association between dietary intake and SUA levels and/or hyperuricemia published until March 2023. Dietary intake patterns were classified into plant-based, animal-based, and mixed dietary patterns based on predominant foods. The pooled effect sizes of eligible studies and their corresponding 95% confidence intervals (CIs) were estimated using random-effects models. Publication bias was assessed using Egger's test. Results: We included 41 studies, comprising 359 317 participants, that investigated the effects of dietary patterns on SUA levels (n = 25) and hyperuricemia (n = 19). Our findings suggested that a plant-based dietary pattern was associated with decreased SUA levels in both interventional (standard mean difference: -0.24 mg dL-1, 95% CI: -0.42, -0.06; I2 = 61.4%) and observational studies (odds ratio (OR): 0.92, 95% CI: 0.89, 0.95, I2 = 91.1%); this association was stronger in men (OR: 0.45, 95% CI: 0.35, 0.58; I2 = 0). We observed that plant- and animal-based dietary patterns were associated with a reduced risk (OR: 0.75; 95% CI: 0.67, 0.83, I2 = 93.3%) and an increased risk (OR: 1.38; 95% CI: 1.20, 1.59, I2 = 88.4%) of hyperuricemia, respectively. Conclusions: Collectively, a plant-based dietary pattern is negatively associated with SUA levels and hyperuricemia. Therefore, a plant-based dietary pattern should be recommended for the management of SUA levels and the prevention of hyperuricemia.

The association between diet quality index-international and inflammatory markers in Iranian overweight and obese women

Objectives

The present study was conducted to evaluate whether there is a link between the diet quality index (DQI) and markers of systemic inflammation in Iranian overweight and obese women.

Methods

This cross-sectional study included 200 Iranian overweight and obese women aged 18-48 years. The DQI-international (DQI-I) comprises four main components: variety, adequacy, moderation, and overall balance. Blood samples were collected in a fasted state to measure inflammatory markers.

Results

After adjusting for age, body mass index (BMI), physical activity, total energy intake, economic status, education, supplement intake, age of starting obesity, and history of body mass loss, a marginally significant negative association was observed between the homeostasis model assessment of insulin resistance (HOMA-IR) and the DQI-I (β: -0.015, 95% CI: -0.03, 0.000; p = 0.061). The results after adjustment showed that DQI-I has a negative association with high-sensitivity C-reactive protein (hs-CRP) concentrations (β: -0.031, 95% CI: -0.104, -0.031; p = 0.023). Furthermore, negative associations were observed between the adequacy component and levels of HOMA-IR (β: -0.025, 95% CI: -0.100, 0.047, p = 0.050) and hs-CRP (β: -0.615, 95% CI: -1.191, -0.020; p = 0.045). In addition, negative associations were found between transforming growth factor-β (TGF-β) and balance score (β: -6.270, 95% CI: -39.211, -3.661, p = 0.020), as well as HOMA-IR (β: -0.080, 95% CI: -0.202, -0.000, p = 0.041) and chemoattractant protein-1 (MCP-1) (β: -0.562, 95% CI: -11.414, -0.282, p = 0.021), with the various component. A marginally significant negative association between galectin 3 (Gal-3) and moderation score (β: -0.451, 95% CI: -1.171, 0.060, p = 0.060) was found. In addition, a marginally significant inverse association was also established between hs-CRP and variety score (β: -0.311, 95% CI: -0.970, 0.001, p = 0.052). The Receiver Operating characteristic (ROC) curve analysis demonstrated that DQI-I might better predict HOMA-IR with a cut point of 3.13 (AUC = 0.698, 0.511-0.699, p = 0.050).

Conclusion

These findings showed that a higher adherence to diet quality and its components could probably be related to lowering the inflammatory markers considerably in overweight and obese women.

A nutritional biomarker score of the Mediterranean diet and incident type 2 diabetes: Integrated analysis of data from the MedLey randomised controlled trial and the EPIC-InterAct case-cohort study

BACKGROUND

Self-reported adherence to the Mediterranean diet has been modestly inversely associated with incidence of type 2 diabetes (T2D) in cohort studies. There is uncertainty about the validity and magnitude of this association due to subjective reporting of diet. The association has not been evaluated using an objectively measured biomarker of the Mediterranean diet.

METHODS AND FINDINGS

We derived a biomarker score based on 5 circulating carotenoids and 24 fatty acids that discriminated between the Mediterranean or habitual diet arms of a parallel design, 6-month partial-feeding randomised controlled trial (RCT) conducted between 2013 and 2014, the MedLey trial (128 participants out of 166 randomised). We applied this biomarker score in an observational study, the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study, to assess the association of the score with T2D incidence over an average of 9.7 years of follow-up since the baseline (1991 to 1998). We included 22,202 participants, of whom 9,453 were T2D cases, with relevant biomarkers from an original case-cohort of 27,779 participants sampled from a cohort of 340,234 people. As a secondary measure of the Mediterranean diet, we used a score estimated from dietary-self report. Within the trial, the biomarker score discriminated well between the 2 arms; the cross-validated C-statistic was 0.88 (95% confidence interval (CI) 0.82 to 0.94). The score was inversely associated with incident T2D in EPIC-InterAct: the hazard ratio (HR) per standard deviation of the score was 0.71 (95% CI: 0.65 to 0.77) following adjustment for sociodemographic, lifestyle and medical factors, and adiposity. In comparison, the HR per standard deviation of the self-reported Mediterranean diet was 0.90 (95% CI: 0.86 to 0.95). Assuming the score was causally associated with T2D, higher adherence to the Mediterranean diet in Western European adults by 10 percentiles of the score was estimated to reduce the incidence of T2D by 11% (95% CI: 7% to 14%). The study limitations included potential measurement error in nutritional biomarkers, unclear specificity of the biomarker score to the Mediterranean diet, and possible residual confounding.

CONCLUSIONS

These findings suggest that objectively assessed adherence to the Mediterranean diet is associated with lower risk of T2D and that even modestly higher adherence may have the potential to reduce the population burden of T2D meaningfully.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12613000602729 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363860.

Dietary fiber intake associated with risk of rheumatoid arthritis among U.S. adults: NHANES 2010-2020

Rheumatoid arthritis (RA) is a prevalent inflammatory joint disease that imposes a significant medical burden and morbidity. Recent scientific evidence suggests that dietary components and patterns could be associated with RA risk. In this study, we aim to investigate the possible relationship between dietary fiber intake and RA risk. We included 15,114 participants from the 2010 to 2020 National Health and Nutrition Examination Survey database in our study. Participants aged 20 or above were categorized into those with and without RA. Univariate logistic regression analysis and multivariate regression models were used to test the association between dietary fiber intake, high-sensitivity C-reactive protein, and RA. Out of all the participants, 1053 were diagnosed with RA (6.97%). Multivariate logistic regression analysis indicated that fiber intake was negatively associated with high-sensitivity c-reactive protein (-0.09 [-0.18, -0.02]) and RA risk (0.99 [0.98, 0.99]). Furthermore, our sensitivity analysis suggested that individuals with higher fiber intake (>19.1 g/day) had a 25% lower risk of developing RA than those with lower fiber intake [0.75 (0.63, 0.88)]. Our findings suggest that higher dietary fiber intake is associated with a reduced risk of RA and may help reduce systemic inflammation, thereby potentially slowing down RA progression.

Mineral water Vincentka and its influence on mucosal ulcers

Gastropathy is one of the most common diseases of the human gastrointestinal tract. Apart from its consequences in the stomach, it is also manifested in other parts of the digestive tract, particularly in the duodenum. The aim of this pilot study was to verify on animal model the empirically observed alleviation of gastropathy symptoms in patients who underwent a drinking treatment of Vincentka natural mineral water during their spa treatment. Sixteen male Wistar rats were included in the study. The animals were randomly divided into two groups: experimental group (E; n=8) and control group (C; n=8). The experimental protocol consisted of three phases: (1) handling phase (7 days); (2) mineral water (E)/tap water (C) administration (7 days); (3) acute gastritis induction (1 day). Twenty-four hours after the induction of acute gastritis, the animals were sacrificed. The collected tissues (stomach and duodenum) and blood were examined by standard histological microscopy, and by immunohistochemical and biochemical methods. Histopathological analysis revealed significantly reduced damage to the gastric mucosa in the experimental group. Significantly different values of blood plasma antioxidant capacity, oxidative stress parameters and blood plasma biochemical parameters were also found. Based on these results, we conclude that the mineral water Vincentka has a positive impact on development and symptoms of acute gastric ulcers.

Redox-Mediated Carbamylation As a Hapten Model Applied to the Origin of Antibodies to Modified Proteins in Rheumatoid Arthritis

Significance: The production of antibodies to posttranslationally modified antigens is a hallmark in rheumatoid arthritis (RA). In particular, the presence of citrullination-associated antibodies, targeting both citrullinating enzymes (the peptidylarginine deiminases [PADs]) and citrullinated antigens (anticitrullinated protein antibodies [ACPAs]), has suggested that dysregulated citrullination is relevant for disease pathogenesis. Antibodies to other protein modifications with physicochemical similarities to citrulline, such as carbamylated-lysine and acetylated-lysine, have also gained interest in RA, but their mechanistic relation to ACPAs remains unclear. Recent Advances: Recent studies using RA-derived monoclonal antibodies have found that ACPAs are cross-reactive to carbamylated and acetylated peptides, challenging our understanding of the implications of such cross-reactivity. Critical Issues: Analogous to the classic antibody response to chemically modified proteins, we examine the possibility that antibodies to modified proteins in RA are more likely to resemble antihapten antibodies rather than autoantibodies. This potential shift in the autoantibody paradigm in RA offers the opportunity to explore new mechanisms involved in the origin and cross-reactivity of pathogenic antibodies in RA. In contrast to citrullination, carbamylation is a chemical modification associated with oxidative stress, it is highly immunogenic, and is considered in the group of posttranslational modification-derived products. We discuss the possibility that carbamylated proteins are antigenic drivers of cross-reacting antihapten antibodies that further create the ACPA response, and that ACPAs may direct the production of antibodies to PAD enzymes. Future Directions: Understanding the complexity of autoantibodies in RA is critical to develop tools to clearly define their origin, identify drivers of disease propagation, and develop novel therapeutics. Antioxid. Redox Signal. 36, 389-409.

Programmable Polymeric Microneedles for Combined Chemotherapy and Antioxidative Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease. Antioxidative treatment combined with chemotherapy holds great promise for RA treatment, and the ability to efficiently deliver drugs and antioxidants to the RA synovial joint is highly desired. Herein, we developed a programmable polymeric microneedle (MN) platform for transdermal delivery of methotrexate (MTX) and reactive oxygen species (ROS) scavengers for RA treatment. The biodegradable MNs made of polyvinylpyrrolidone (PVP) were incorporated with polydopamine/manganese dioxide (termed PDA@MnO₂) and MTX. After insertion into skin tissue, the MNs degraded, thus enabling release of loaded MTX and PDA@MnO₂. The PDA@MnO₂ could be utilized as an MRI contrast agent in the RA synovial microenvironment. It also acted as a robust antioxidant to remove ROS and decrease RA inflammation, which when combined with the MTX-mediated chemotherapy led to an ideal outcome for RA treatments in a murine model. This work not only represents a valuable MN-assisted RA therapeutic agent transdermal delivery approach but also opens a new avenue for chemotherapy and antioxidative synergistic treatment of RA.

Dietary patterns and biomarkers of oxidative stress and inflammation: A systematic review of observational and intervention studies

INTRODUCTION

Oxidative stress and inflammation are known to play a critical role in ageing and chronic disease development and could therefore represent important targets for developing dietary strategies for disease prevention. We aimed to systematically review the results from observational studies and intervention trials published in the last 5 years on the associations between dietary patterns and biomarkers of oxidative stress and inflammation.

METHODS

A systematic search of the PubMed, MEDLINE and Web of Science (January 2015 to October 2020) was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological quality of selected studies was evaluated based on the NUTRIGRADE and BIOCROSS assessment tools.

RESULTS

In total, 29 studies among which 16 observational studies and 13 intervention studies were found eligible for review. Overall, results indicated an inverse association between plant-based diets - the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diet - and oxidative stress and proinflammatory biomarkers. In observational studies, inverse associations were further revealed for the vegetarian diet, the USDA Healthy Eating Index (HEI) - based diet and the paleolithic diet, whereas a positive association was seen for western and fast food diets. Quality assessment suggested that majority of dietary intervention studies (n = 12) were of low to moderate quality.

CONCLUSIONS

This study provides evidence that the plant-based dietary patterns are associated with lowered levels of oxidative stress and inflammation and may provide valid means for chronic disease prevention. Future large-scale intervention trials using validated biomarkers are warranted to confirm these findings.

Evaluation of levels of oxidative stress as a potential biomarker in patients with rheumatoid arthritis

Objectives:

One of the most prevalent autoimmune disease globally, rheumatoid arthritis (RA) is caused by interplay of multiple inflammatory mediators in specific joints. Altered redox balance is one of the key factors in pathophysiology of RA. This study aims to find whether oxidative stress in peripheral blood neutrophil correlates with the disease activity and disability associated with it.

Methods:

Ten healthy controls and 29 RA patients with moderate to severe disease activity (DAS28 score >3.2) were recruited and reactive oxygen species (ROS) level in peripheral blood neutrophil was measured using flow cytometry at baseline visit and after 6 months follow-up. Functional status of RA patients was measured using Health Assessment Questionnaire Disability Index (HAQ-DI).

Results:

RA patients showed significantly higher level of ROS in compared to healthy control. DAS28 correlated well with ROS at baseline visit (Pearson's r = +0.63) as well as follow-up visit (Pearson's r = +0.75). HAQ-DI showed weak positive correlation at baseline visit (Pearson's r = 0.1) but it was negative at follow-up visit (Pearson's r = -0.19).

Conclusions:

Oxidative stress mirrors the disease activity in RA and can be considered as a biomarker, but it is not related with functional ability of the patients.

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.

Si Miao San Attenuates Inflammation and Oxidative Stress in Rats with CIA via the Modulation of the Nrf2/ARE/PTEN Pathway

Objective

Si Miao San (SMS) is a traditional Chinese formula used in China to treat rheumatic diseases. To date, its mechanism in rheumatoid arthritis (RA) treatment is uncertain. Our study aims to assess the antiarthritic effects of SMS in experimental arthritic rats.

Materials and Methods

SMS (8.63, 4.31, and 2.16 g/kg/day) was orally administered after the first immunization from day 14 to day 53. The effects of SMS on rats with collagen-induced arthritis (CIA) were evaluated by arthritis score and histological assessment. The levels of cytokines and anti-CII antibodies in rat serum were measured by ELISAs. The expression of oxidative stress parameters was detected by biochemical assay kits. The levels of Nrf2, HO-1, NQO1, and PTEN were determined by western blotting.

Results

Medium- and high-dose SMS treatment significantly decreased arthritis scores and alleviated ankle joint histopathology in the rats with CIA. It inhibited the production of IL-6, TNF-α, COX-2, and PGE2 in rat serum. SMS also suppressed the expression of anti-CII antibodies IgG1 and IgG2a. Moreover, SMS significantly suppressed the levels of MDA and MPO in the synovial tissues while increasing the levels of SOD and CAT in the rats with CIA. The levels of Nrf2, HO-1, NQO1, and PTEN were upregulated by SMS in rat synovial tissues.

Conclusions

This study demonstrated that SMS effectively alleviated the disease progression of CIA by decreasing the levels of proinflammatory cytokines and reducing oxidative stress damage, as indicated by IL-6, TNF-α, COX-2, and PGE2 levels; inhibiting the overproduction of MDA and MPO; and enhancing antioxidant enzymes by upregulating the Nrf2/ARE/PTEN signalling pathway.

The Effect of the Mediterranean Diet on Metabolic Health: A Systematic Review and Meta-Analysis of Controlled Trials in Adults

The Mediterranean diet (MD) may provide metabolic benefits but no systematic review to date has examined its effect on a multitude of outcomes related to metabolic health. This systematic review with meta-analysis (International Prospective Register of Systematic Reviews, PROSPERO; number CRD42019141459) aimed to examine the MD’s effect on metabolic syndrome (MetSyn) incidence, components and risk factors (primary outcomes), and incidence and/or mortality from MetSyn-related comorbidities and receipt of pharmacologic treatment for MetSyn components and comorbidities (secondary outcomes). We searched Pubmed, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Web of Science for controlled trials published until June 2019, comparing the MD with no treatment, usual care, or different diets in adults. Studies not published in English and not promoting the whole MD were excluded. Two authors independently extracted data and assessed risk of bias using the Cochrane Collaboration’s and Risk of Bias in non-randomised studies (ROBINS-I) tools. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Random-effects meta-analyses, subgroup analyses and meta-regressions were performed, and heterogeneity was quantified using the I² statistic. We identified 2654 reports and included 84 articles reporting 57 trials (n = 36,983). In random effects meta-analyses, the MD resulted in greater beneficial changes in 18 of 28 MetSyn components and risk factors (body weight, body mass index, waist circumference, systolic and diastolic blood pressure, glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR) index, total-, low-density lipoprotein (LDL)- and high-density lipoprotein (HDL)-cholesterol, triglycerides, alanine transaminase, hepatic fat mass, C-reactive protein, interleukin-6, tumour necrosis factor-a, and flow-mediated dilatation) and lower risk of cardiovascular disease incidence (risk ratio (RR) = 0.61, 95% confidence intervals (CI) 0.42–0.80; I² = 0%), and stroke (RR = 0.67, 95% CI 0.35–0.98; I² = 0%). Only six studies reported effects on pharmacotherapy use, and pooled analysis indicated no differences between diet groups. Lack of consistency in comparator groups and other study characteristics across studies resulted in high heterogeneity for some outcomes, which could not be considerably explained by meta-regressions. However, a consistent direction of beneficial effect of the MD was observed for the vast majority of outcomes examined. Findings support MD’s beneficial effect on all components and most risk factors of the MetSyn, in addition to cardiovascular disease and stroke incidence. More studies are needed to establish effects on other clinical outcomes and use of pharmacotherapy for MetSyn components and comorbidities. Despite the high levels of heterogeneity for some outcomes, this meta-analysis enabled the comparison of findings across studies and the examination of consistency of effects. The consistent direction of effect, suggesting the MD’s benefits on metabolic health, supports the need to promote this dietary pattern to adult populations.

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.

The relationship between dietary patterns and rheumatoid arthritis: a case-control study

Background and aim

A number of studies have investigated the effects of individual foods and/or nutrients on rheumatoid arthritis (RA), but research focusing on whole dietary patterns remains limited. The association of dietary patterns and rheumatoid arthritis is therefore not well elucidated. This study aims to determine existing relationships between major identified dietary patterns and RA.

Methods

This matched case-control study was conducted on 297 individuals in Isfahan, Iran. The presence of RA was determined by an expert rheumatologist, based on the American College of Rheumatology definitions, 2010. A 168-item questionnaire was used to collect dietary data. Major dietary patterns were identified using the factor analysis method.

Results

Two major dietary patterns, namely, healthy and western dietary patterns, were identified. Lower adherence to the healthy dietary pattern was associated with increased risk of RA (OR = 2.80; 95% CI 1.74-4.67; P < 0.001). The association remained significant even after taking other confounders into account (OR = 2.85; 95% CI 1.12-7.45; P = 0.03). A positively significant association was also observed between adherence to western dietary pattern and RA in the fully-adjusted final model (OR = 2.22; 95% CI 1.04-4.72; P = 0.03).

Conclusions

The study suggests that there is an inverse association between adherence to a healthy dietary pattern and the odds of RA, and a positive significant relationship was found between western dietary pattern and RA. Further studies are required to confirm these findings.

Ideal food pyramid for patients with rheumatoid arthritis: A narrative review

Emerging literature suggests that diet plays an important modulatory role in rheumatoid arthritis (RA) because diet is an environmental factor that affects inflammation, antigen presentation, antioxidant defense mechanisms and gut microbiota. Patients with RA frequently ask their doctors about which diets to follow, and even in the absence of advice from their physicians, many patients are undertaking various dietary interventions. Given this background, the aim of this review is to evaluate the evidence to date regarding the ideal dietary approach for management of RA in order to reduce the counteracting inflammation, and to construct a food pyramid for patients with RA. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains, preferably gluten free), together with fruits and vegetables (5 portions; among which fruit, berries and citrus fruit are to be preferred, and among the vegetables, green leafy ones.), light yogurt (125 ml), skim milk (200 ml), 1 glass (125 ml) of wine and extra virgin olive oil; weekly, fish (3 portions), white meat (3 portions), legumes (2 portions) eggs (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: one green means that subjects with RA need some personalized supplementation (vitamin D and omega 3) and one red means that there are some foods that are banned (salt and sugar). The food pyramid allows patients to easily figure out what to eat.

Vitamin C Deficiency and the Risk of Osteoporosis in Patients with an Inflammatory Bowel Disease

Recent research studies have shown that vitamin C (ascorbic acid) may affect bone mineral density and that a deficiency of ascorbic acid leads to the development of osteoporosis. Patients suffering from an inflammatory bowel disease are at a risk of low bone mineral density. It is vital to notice that patients with Crohn’s disease and ulcerative colitis also are at risk of vitamin C deficiency which is due to factors such as reduced consumption of fresh vegetables and fruits, i.e., the main sources of ascorbic acid. Additionally, some patients follow diets which may provide an insufficient amount of vitamin C. Moreover, serum vitamin C level also is dependent on genetic factors, such as SLC23A1 and SLC23A2 genes, encoding sodium-dependent vitamin C transporters and GSTM1, GSTP1 and GSTT1 genes which encode glutathione S-transferases. Furthermore, ascorbic acid may modify the composition of gut microbiota which plays a role in the pathogenesis of an inflammatory bowel disease.

Oxidative Stress in Rheumatoid Arthritis: What the Future Might Hold regarding Novel Biomarkers and Add-On Therapies

Numerous rheumatologic autoimmune diseases, among which rheumatoid arthritis, are chronic inflammatory diseases capable of inducing multiple cumulative articular and extra-articular damage, if not properly treated. Nevertheless, benign conditions may, similarly, exhibit arthritis as their major clinical finding, but with short-term duration instead, and evolve to spontaneous resolution in a few days to weeks, without permanent articular damage. Such distinction—self-limited arthritis with no need of immunosuppressive treatment or chronic arthritis at early stages?—represents one of the greatest challenges in clinical practice, once many metabolic, endocrine, neoplastic, granulomatous, infectious diseases and other autoimmune conditions may mimic rheumatoid arthritis. Indeed, the diagnosis of rheumatoid arthritis at early stages is a crucial step to a more effective mitigation of the disease-related damage. As a prototype of chronic inflammatory autoimmune disease, rheumatoid arthritis has been linked to oxidative stress, a condition in which the pool of reactive oxygen species increases over time, either by their augmented production, the reduction in antioxidant defenses, or the combination of both, ultimately implying compromise in the redox signaling. The exact mechanisms through which oxidative stress may contribute to the initiation and perpetuation of local (in the articular milieu) and systemic inflammation in rheumatoid arthritis, particularly at early stages, still remain to be determined. Furthermore, the role of antioxidants as therapeutic adjuvants in the control of disease activity seems to be overlooked, as a little number of short studies addressing this issue is currently found. Thus, the present review focuses on the binomial rheumatoid arthritis-oxidative stress, bringing insights into their pathophysiological relationships, as well as the implications of potential diagnostic oxidative stress biomarkers and therapeutic interventions directed to the oxidative status in patients with rheumatoid arthritis.

Mitochondrial dysfunction in rheumatoid arthritis: A comprehensive analysis by integrating gene expression, protein-protein interactions and gene ontology data

Several studies have reported mitochondrial dysfunction in rheumatoid arthritis (RA). Many nuclear DNA (nDNA) encoded proteins translocate to mitochondria, but their participation in the dysfunction of this cell organelle during RA is quite unclear. In this study, we have carried out an integrative analysis of gene expression, protein-protein interactions (PPI) and gene ontology data. The analysis has identified potential implications of the nDNA encoded proteins in RA mitochondrial dysfunction. Firstly, by analysing six synovial microarray datasets of RA patients and healthy controls obtained from the gene expression omnibus (GEO) database, we found differentially expressed nDNA genes that encode mitochondrial proteins. We uncovered some of the roles of these genes in RA mitochondrial dysfunction using literature search and gene ontology analysis. Secondly, by employing gene co-expression from microarrays and collating reliable PPI from seven databases, we created the first mitochondrial PPI network that is specific to the RA synovial joint tissue. Further, we identified hubs of this network, and moreover, by integrating gene expression and network analysis, we found differentially expressed neighbours of the hub proteins. The results demonstrate that nDNA encoded proteins are (i) crucial for the elevation of mitochondrial reactive oxygen species (ROS) and (ii) involved in membrane potential, transport processes, metabolism and intrinsic apoptosis during RA. Additionally, we proposed a model relating to mitochondrial dysfunction and inflammation in the disease. Our analysis presents a novel perspective on the roles of nDNA encoded proteins in mitochondrial dysfunction, especially in apoptosis, oxidative stress-related processes and their relation to inflammation in RA. These findings provide a plethora of information for further research.

Effects of Mediterranean diet on the treatment of rheumatoid arthritis

INTRODUCTION

It has been suggested that environmental and lifestyle factors might contribute to the severity and progression of inflammation in rheumatoid arthritis. An intervention generating high interest due to its supposed anti-inflammatory properties is the Mediterranean diet.

METHODS

We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

RESULTS AND CONCLUSIONS

We identified seven systematic reviews including four primary studies, of which only one corresponded to a randomized trial. We concluded Mediterranean diet may make little or no difference in pain or disease activity and may slightly increase weight in rheumatoid arthritis patients, but the certainty of the evidence is low. On the other hand, it was not possible to clearly establish whether Mediterranean diet has any effect on functionality, morning stiffness or quality of life as the certainty of the existing evidence has been assessed as very low.

Ad libitum Mediterranean diet reduces subcutaneous but not visceral fat in patients with coronary heart disease: A randomised controlled pilot study

BACKGROUND & AIMS

The Mediterranean diet (MedDiet) is recognised to reduce risk of coronary heart disease (CHD), in part, via its anti-inflammatory and antioxidant properties, which may be mediated via effects on body fat distribution. Diet efficacy via these mechanisms is however unclear in patients with diagnosed CHD. This study aimed to determine: (1) the effect of ad libitum MedDiet versus low-fat diet intervention on adiposity, anti-inflammatory marker adiponectin, oxidative stress marker malondialdehyde (MDA) and traditional CVD risk markers, and (2) whether improvement in MedDiet adherence score in the pooled cohort was associated with these risk markers, in a pilot cohort of Australian patients post coronary event.

METHODS

Participants (62 ± 9 years, 83% male) were randomised to 6-month ad libitum MedDiet (n = 34) or low-fat diet (n = 31). Pre- and post-intervention, dietary adherence, anthropometry, body composition (Dual-energy X-ray Absorptiometry) and venepuncture measures were conducted.

RESULTS

The MedDiet group reduced subcutaneous adipose tissue (SAT) area compared to the low-fat diet group (12.5 cm² more, p = 0.04) but not visceral adipose tissue or other body composition measures. In the pooled cohort, participants with greatest improvement in MedDiet adherence score had significantly lower waist circumference (-2.81 cm, p = 0.01) and SAT area (-27.1 cm², p = 0.04) compared to participants with no improvement in score at 6-months. There were no changes in adiponectin, MDA or other risk markers in the MedDiet compared to low-fat diet group, and no differences in 6-month levels between categories of improvement in MedDiet score (p > 0.05). Within the MedDiet group only, the proportion of participants taking beta-blocker medication reduced from baseline to 6-months (71% vs. 56%, p-trend = 0.007).

CONCLUSIONS

Adherence to 6-month ad libitum MedDiet reduced subcutaneous fat and waist circumference which discounts the misconception that this healthy but high fat diet leads to body fat gain. The effect of MedDiet on body fat distribution and consequent anti-inflammatory and antioxidant effects, as well as need for medications, in patients with CHD warrants exploration in larger studies. Clinically significant effects on these markers may require adjunct exercise and/or caloric restriction.

TRIAL REGISTRATION

ACTRN12616000156482.

Association between dietary intake of some antioxidant micronutrients with some inflammatory and antioxidant markers in active Rheumatoid Arthritis patients

Background: Rheumatoid Arthritis (RA) is an autoimmune disease. Antioxidants intake and body antioxidants status are important in patients with RA. The aim of this study was to investigate the association between dietary intake of some antioxidant micronutrients with some inflammatory and antioxidant markers in patients with active rheumatoid arthritis and comparison with Recommended Dietary Allowance (RDA). Materials and Methods: In this cross-sectional study, eighty-seven patients with active rheumatoid arthritis were included. Dietary antioxidants intake was measured using 24-hour recall questionnaire and food record (3 days). Blood levels of inflammatory and antioxidant markers were determined by laboratory tests. The association between intake of antioxidants with inflammatory and antioxidant markers, and also with RDA were determined using Paired-Samples t-test and Pearson correlation by SPSS software. Results: The findings showed that intakes of vitamin E, zinc, and magnesium in patients were significantly lower and intakes of copper and selenium were significantly higher than RDA (P < 0.05). Significant negative correlations were observed between vitamin A intake with PGE2 [R = -0.31], vitamin C intake with IL-1β [R = -0.25], zinc intake with PGE2 [R = -0.30], IL-2 [R = -0.23], and the activity of glutathione reductase enzyme [R = -0.21], magnesium intake with PGE2 [R = -0.24], IL-1β [R = -0.23] and IL-2 [R = -0.25], and selenium intake with PGE2 [R = -0.21] (P < 0.05). Also, significant positive correlations were observed between intakes of vitamin E and copper with catalase enzyme activity [R = 0.22 and R = 0.21 respectively] (P < 0.05). Conclusion: Some of the antioxidant micronutrients play important roles in the reduction of inflammatory conditions and improve the function of antioxidant enzymes in patients with rheumatoid arthritis.

Neutrophils and redox stress in the pathogenesis of autoimmune disease

Polymorphonuclear leukocytes, or neutrophils, are specialist phagocytic cells of the innate immune system. Their primary role is host defence against micro-organisms, which they kill via phagocytosis, followed by release of reactive oxygen species (ROS) and proteolytic enzymes within the phagosome. ROS are generated via the action of the NADPH oxidase (also known as NOX2), in a process termed the 'Respiratory Burst'. This process consumes large amounts of oxygen, which is converted into the highly-reactive superoxide radical O₂^- and H₂O₂. Subsequent activation of myeloperoxidase (MPO) generates secondary oxidants and chloroamines that are highly microbiocidal in nature, which together with proteases such as elastase and gelatinase provide a toxic intra-phagosomal environment able to kill a broad range of micro-organisms. However, under certain circumstances such as during an auto-immune response, neutrophils can be triggered to release ROS and proteases extracellularly causing damage to host tissues, modification of host proteins, lipids and DNA and dysregulation of oxidative homeostasis. This review describes the range of ROS species produced by human neutrophils with a focus on the implications of neutrophil redox products in autoimmune inflammation.

Diet Quality and Its Relationship with Antioxidant Status in Patients with Rheumatoid Arthritis

A direct contribution towards destructive, proliferative synovitis in rheumatoid arthritis (RA) has been attributed to reactive oxygen species action. Some nutrients are considered to be capable of improving the oxidant/antioxidant status in RA; however the impact of diet composition on the antioxidant capacity of serum has not yet been studied in this disease. The aim of the study was to assess the relationship between diet quality and antioxidant status in patients with RA and healthy controls. Nutritional assessment was performed, and antioxidant status in serum, without and with deproteinization (TAS and DSAS, resp.), was determined in 82 RA and 87 healthy subjects. The diet of the RA group was low-energy and imbalanced. TAS and DSAS were significantly lower in RA patients than in controls. Antioxidant status significantly correlated with the supply of foods and nutrients influencing antioxidant and anti-inflammatory defense in RA; however, in this group, TAS was more sensitive to diet than DSAS. In healthy subjects, the nonprotein pool of serum antioxidants was more tightly linked to diet. These outcomes indicate the need to monitor diet quality of patients with RA and the usefulness of TAS measurements in this monitoring.

A randomised study in young subjects of the effects of eating extra fruit or nuts on periodontal inflammation

Objectives/Aims:

Fruit is often advocated as a healthy source of nutrients and vitamins. However, the high contents of sugars in many fruits could potentially counteract positive effects on the teeth.

Materials and methods:

We recruited 30 healthy non-obese participants who were randomised to either supplement their diet with extra fruits or nuts, each at +7 kcal/kg body weight/day, for 2 months.

Results:

Fructose intake increased from 9.1±6.0 to 25.6±9.6 g/day, P<0.0001, in the fruit group and was reduced from 12.4±5.7 to 6.5±5.3 g/day, P=0.007, in the nut group. Serum-vitamin C increased in both groups (fruit: P=0.017; nuts: P=0.009). α-Tocopherol/cholesterol ratio increased in the fruit group (P=0.0033) while β-carotene/cholesterol decreased in the nut group (P<0.0001). The amount of subjects with probing pocket depths ⩾4 mm in the fruit group was reduced (P=0.045) according to blinded examinations, and the difference in the changes in probing pockets ⩾4 mm was also statistically significant between the food groups (P=0.010).

Conclusion:

A large increase of fruit intake, compared with nuts, had a favourable effect on periodontal status in some respects, despite the high sugar contents. To search for potential protective micronutrients in fruit that protect the teeth could be an aim for further research.

Role of Diet in Influencing Rheumatoid Arthritis Disease Activity

BACKGROUND

Patients with Rheumatoid Arthritis (RA) frequently ask their doctors about which diets to follow, and even in the absence of advice from their physicians, many patients are undertaking various dietary interventions.

DISCUSSION

However, the role of dietary modifications in RA is not well understood. Several studies have tried to address these gaps in our understanding. Intestinal microbial modifications are being studied for the prevention and management of RA. Some benefits of vegan diet may be explained by antioxidant constituents, lactobacilli and fibre, and by potential changes in intestinal flora. Similarly, Mediterranean diet shows anti-inflammatory effects due to protective properties of omega-3 polyunsaturated fatty acids and vitamins, but also by influencing the gut microbiome. Gluten-free and elemental diets have been associated with some benefits in RA though the existing evidence is limited. Long-term intake of fish and other sources of long-chain polyunsaturated fatty acids are protective for development of RA. The benefits of fasting, anti-oxidant supplementation, flavanoids, and probiotics in RA are not clear. Vitamin D has been shown to influence autoimmunity and specifically decrease RA disease activity. The role of supplements such as fish oils and vitamin D should be explored in future trials to gain new insights in disease pathogenesis and develop RA-specific dietary recommendations.

CONCLUSION

Specifically more research is needed to explore the association of diet and the gut microbiome and how this can influence RA disease activity.

The role of the gut microbiome in systemic inflammatory disease

The role of the gut microbiome in models of inflammatory and autoimmune disease is now well characterized. Renewed interest in the human microbiome and its metabolites, as well as notable advances in host mucosal immunology, has opened multiple avenues of research to potentially modulate inflammatory responses. The complexity and interdependence of these diet-microbe-metabolite-host interactions are rapidly being unraveled. Importantly, most of the progress in the field comes from new knowledge about the functional properties of these microorganisms in physiology and their effect in mucosal immunity and distal inflammation. This review summarizes the preclinical and clinical evidence on how dietary, probiotic, prebiotic, and microbiome based therapeutics affect our understanding of wellness and disease, particularly in autoimmunity.

Anti-arthritogenic and cardioprotective action of hesperidin and daidzein in collagen-induced rheumatoid arthritis

Atherosclerosis has been linked to chronic inflammatory processes. Changes in the levels of lipoproteins, especially low-density lipoprotein or its variants, as well as inflammatory markers are risk factors for the atherosclerosis. In the present study, an experimental model of rheumatoid arthritis was developed by administrating collagen suspension intradermally in the tail region of Wistar albino rats. At the same time, a suspension of hesperidin (50 mg/kg body weight) and daidzein (20 mg/kg body weight) was orally administrated. The compounds were given in the morning and evening for 21 days. Levels of inflammatory markers in the homogenate of knee joints of experimental rats as well as plasma lipoproteins were investigated. The administration of hesperidin and daidzein caused significant (p < 0.001) decrease in articular elastase activity, TNF-α, and malondialdehyde levels. Further, arthritis scoring and histological findings supported the anti-inflammatory actions of the test compounds. Interestingly, the test compounds also lowered the plasma low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, and triglyceride but increased the level of high-density lipoprotein cholesterol. The test compounds thus ameliorated the risk factors of atherosclerosis. Furthermore, antioxidant roles of hesperidin as well as daidzein were evident from decrease in free radical load demonstrated as increase in total antioxidant level in plasma of arthritic animals treated with hesperidin and daidzein. In a separate in vitro experiment, enhanced free radical scavenging activity of hesperidin was demonstrated against 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid. The anti-inflammatory, hypolipidemic, and antioxidant actions of the naturally occurring test compounds, particularly hesperidin, seem to be quite effective against rheumatoid arthritis and atherosclerosis. Thus, their consumption may be helpful in prevention or at least delaying the onset of these diseases in susceptible individuals.

Healthy Dietary Patterns and Oxidative Stress as Measured by Fluorescent Oxidation Products in Nurses' Health Study

Healthy diets may lower oxidative stress and risk of chronic diseases. However, no previous studies examined associations between diet and fluorescent oxidation products (FlOP), a global marker of oxidative stress. We evaluated associations between healthy eating patterns (Alternative Healthy Eating Index (AHEI), Dietary Approach to Stop Hypertension (DASH), and Alternate Mediterranean Diet (aMED)) and FlOP, measured at three excitation/emission wavelengths (FlOP_360, FlOP_320, FlOP_400) from 2021 blood samples collected from 1688 women within the Nurses’ Health Study. AHEI, DASH, and aMED scores were significantly positively associated with FlOP_360 and FlOP_320 concentrations (p-trend ≤ 0.04), but not associated with FlOP_400. Among specific food groups that contribute to these diet scores, significantly positive associations were observed with legumes and vegetables for FlOP_360, vegetables and fruits for FlOP_320, and legumes and alcohol for FlOP_400. Inverse associations were observed with nuts, sweets or desserts, and olive oil for FlOP_360, nuts for FlOP_320 and sweets or desserts for FlOP_400 (all p-trend ≤ 0.05). However, FlOP variation due to diet was small compared to overall FlOP variation. In conclusion, AHEI, DASH, and aMED scores were unexpectedly positively, but weakly, associated with FlOP_360 and FlOP_320. However, these findings should be interpreted cautiously as the determinants of FlOP concentrations are not fully understood.

Reactive oxygen and nitrogen species in patients with rheumatoid arthritis as potential biomarkers for disease activity and the role of antioxidants

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have distinct contribution to the destructive, proliferative synovitis of rheumatoid arthritis (RA) and play a prominent role in cell-signaling events. However, few studies had clarified the role of individual ROS and RNS in the etiopathogenesis of RA. To date, most of the studies were concerned with the measurement of the total oxidative and nitrative stress levels in RA. The aim of this study was to monitor the levels of individual ROS and RNS to emphasize the role that each plays in the pathogenesis of RA and their usefulness as possible biomarkers for the disease activity. In addition, the effect of an antioxidant (ascorbic acid), added to the treatment regimen, on the levels of ROS, RNS and disease activity has been evaluated. Forty-two Saudi RA patients and 40 healthy controls of both genders were included in this study. Serum levels of six different ROS and three different RNS were measured using specific fluorescent probes. The ROS included the hydroxyl radical ((•)OH), the superoxide anion (O2(•-)), hydrogen peroxide (H2O2), the singlet oxygen ((1)O2), the hypochlorite radical (OHCl(•)), and the peroxyl radical (ROO(•)). The RNS included nitric oxide (NO(•)), nitrogen dioxide (ONO-) and peroxynitrite (ONOO-). The main clinical and biochemical markers for disease activity were assessed and correlated with ROS and RNS levels. The clinical markers included the 28 swollen joint count (SJC-28), the 28-tender joint count (TJC-28), morning stiffness and symmetric arthritis, in addition to the disease activity score assessing 28 joints with erythrocyte sedimentation rate (DAS28-ESR). The biochemical markers included undercarboxylated osteocalcin (ucOC), matrix metalloproteinase (MMP-3), ESR, C-reactive protein (CRP), rheumatoid factor (RF) and anticyclic citrullinated polypeptide (Anti-CCP). Ascorbic acid (1mg/day) was added as an antioxidant to the regular treatment regimen of RA patients for two months, and the levels of ROS and RNS, as well as disease activity were re-evaluated. The results have shown significant higher serum levels of individual ROS and RNS in RA patients compared with healthy subjects. Moreover, this study might be the first to report strong positive correlations between most of the reactive species and the clinical and biochemical markers of RA. Interestingly, the addition of ascorbic acid had significantly reduced the levels of all ROS and RNS in RA patients. In conclusion, the role of oxidative and nitrative stress in the pathogenesis of RA has been confirmed by this study. Serum levels of ROS and RNS may effectively serve as biomarkers for monitoring disease progression. Finally, the addition of an antioxidant, such as ascorbic acid, in the management of RA may be of a great value.

The metabolic role of the gut microbiota in health and rheumatic disease: mechanisms and interventions

The role of the gut microbiome in animal models of inflammatory and autoimmune disease is now well established. The human gut microbiome is currently being studied as a potential modulator of the immune response in rheumatic disorders. However, the vastness and complexity of this host-microorganism interaction is likely to go well beyond taxonomic, correlative observations. In fact, most advances in the field relate to the functional and metabolic capabilities of these microorganisms and their influence on mucosal immunity and systemic inflammation. An intricate relationship between the microbiome and the diet of the host is now fully recognized, with the microbiota having an important role in the degradation of polysaccharides into active metabolites. This Review summarizes the current knowledge on the metabolic role of the microbiota in health and rheumatic disease, including the advances in pharmacomicrobiomics and its potential use in diagnostics, therapeutics and personalized medicine.

A Randomized Study of the Effects of Additional Fruit and Nuts Consumption on Hepatic Fat Content, Cardiovascular Risk Factors and Basal Metabolic Rate

Background

Fruit has since long been advocated as a healthy source of many nutrients, however, the high content of sugars in fruit might be a concern.

Objectives

To study effects of an increased fruit intake compared with similar amount of extra calories from nuts in humans.

Methods

Thirty healthy non-obese participants were randomized to either supplement the diet with fruits or nuts, each at +7 kcal/kg bodyweight/day for two months. Major endpoints were change of hepatic fat content (HFC, by magnetic resonance imaging, MRI), basal metabolic rate (BMR, with indirect calorimetry) and cardiovascular risk markers.

Results

Weight gain was numerically similar in both groups although only statistically significant in the group randomized to nuts (fruit: from 22.15±1.61 kg/m² to 22.30±1.7 kg/m², p = 0.24 nuts: from 22.54±2.26 kg/m² to 22.73±2.28 kg/m², p = 0.045). On the other hand BMR increased in the nut group only (p = 0.028). Only the nut group reported a net increase of calories (from 2519±721 kcal/day to 2763±595 kcal/day, p = 0.035) according to 3-day food registrations. Despite an almost three-fold reported increased fructose-intake in the fruit group (from 9.1±6.0 gram/day to 25.6±9.6 gram/day, p<0.0001, nuts: from 12.4±5.7 gram/day to 6.5±5.3 gram/day, p = 0.007) there was no change of HFC. The numerical increase in fasting insulin was statistical significant only in the fruit group (from 7.73±3.1 pmol/l to 8.81±2.9 pmol/l, p = 0.018, nuts: from 7.29±2.9 pmol/l to 8.62±3.0 pmol/l, p = 0.14). Levels of vitamin C increased in both groups while α-tocopherol/cholesterol-ratio increased only in the fruit group.

Conclusions

Although BMR increased in the nut-group only this was not linked with differences in weight gain between groups which potentially could be explained by the lack of reported net caloric increase in the fruit group. In healthy non-obese individuals an increased fruit intake seems safe from cardiovascular risk perspective, including measurement of HFC by MRI.

Trial Registration

ClinicalTrials.gov NCT02227511

The onset of lipid peroxidation in rheumatoid arthritis: consequences and monitoring

Several epidemiological studies propose the association of rheumatoid arthritis (RA) with oxidative stress. The aim of this study was to estimate the possible onset of systemic lipid peroxidation in RA patients and its relevance for pathophysiology and monitoring of RA. Seventy-three patients with RA and 73 healthy subjects were included in the study. Lipid peroxidation was estimated by the measurement of 4-hydroxynonenal (4-HNE), 4-hydroxyhexenal, malondialdehyde, acrolein, crotonaldehyde, 4-oxononenal, and isoprostanes (8-isoPGF(2α)) levels. Cytosolic phospholipase A(2) (cPLA(2)), platelet-activating factor acetylhydrolase (PAF-AH) and glutathione peroxidase (GSH-Px) activities and vitamin E levels were also determined. In parallel, the plasma levels of phospholipid arachidonic acid (AA), linoleic acid (LA), and 4-HNE-protein adducts were monitored. Plasma of RA patients had increased vitamin E levels, but decreased GSH-Px activity and phospholipid AA and LA levels when compared to levels of the healthy subjects. The levels of aldehydes were significantly increased in the plasma of the RA patients and even more in urine. Significant increases in HNE-modified protein adducts was observed for the first time in plasma of RA patients, while the activities of PAF-AH and cPLA(2) were decreased. The 8-isoPGF(2α) levels were 9-fold higher in plasma and 3-fold higher in urine of RA patients and were related to the severity of disease. The levels of lipid peroxidation products in plasma and in urine suggest the relationship between lipid peroxidation and the development of RA. Additionally, urine 8-isoPGF(2α), plasma 4-HNE and 4-HNE-protein adducts appear to be convenient biomarkers to monitor progression of this autoimmune disease.

Management of symptomatic erosive-ulcerative lesions of oral lichen planus in an adult Egyptian population using Selenium-ACE combined with topical corticosteroids plus antifungal agent

Aim:

Oral lichen planus (OLP) is a chronic mucocutaneous disease with an immunological etiology. This study was conducted to evaluate the effect of selenium combined with Vitamins A, C & E (Selenium-ACE) in the treatment of erosive-ulcerative OLP as an adjunctive to topical corticosteroids plus antifungal agent.

Subjects and Methods:

Thirty patients with a confirmed clinical and histopathologic diagnosis of OLP participated in this clinical trial. Patients were randomly allocated into one of three groups and treated as follows: (I) Topical corticosteroids, (II) topical corticosteroids plus antifungal, and (III) SE-ACE combined with topical corticosteroids plus antifungal. The patients were followed for 6 weeks. The pain and severity of the lesions were recorded at the initial and follow-up visits. All recorded data were analyzed using paired t-test and ANOVA test. A P ≤ 0.05 was considered significant.

Results:

The experimental groups showed a marked reduction in pain sensation and size of lesions, particularly in the final follow-up period, but there was no significant difference between the first two Groups I and II. However, healing of lesions and improvement of pain sensation was effective in Group III since a significant difference was found favoring Group III over both Groups I and II.

Conclusion:

No significant difference was found in treating erosive-ulcerative lesions of OLP by topical corticosteroids alone or combined with antifungal. However, when using SE-ACE in combination with topical corticosteroids plus antifungal, this approach may be effective in managing ulcerative lesions of OLP; but more research with a larger sample size and a longer evaluation period may be recommended.

Intake of antioxidants in patients with rheumatoid arthritis

OBJECTIVE

to investigate dietary intake of antioxidants in patients with rheumatoid arthritis.

METHODS

this is a cross-sectional case series study with 53 women accompanied at the Rheumatology Outpatient Clinic, Hospital das Clínicas/UFPE, from January to October 2012. Demographic and anthropometric parameters (weight, height, body mass index, weight change) were collected by means of a form. The assessment of food consumption was conducted using a semi-quantitative food frequency survey, analyzed according to a food composition table. Database construction and statistical analysis were performed using Excel and SPSS version 18.0, using chi-squared test, Anova, and Student's t-test, at a confidence level of 5%.

RESULTS

the sample was composed of 53 women with a mean age of 54.51 ± 4.24 years and BMI of 25.97 ± 5.94 kg/m². In the sociodemographic variables, statistically significant differences in origin, occupation, and income were observed. Daily consumption showed significance for vitamins A, C, and zinc. In adults, vitamins A and C were in accordance with recommendations, while in the elderly a low intake of vitamin E and selenium was observed. The relation between vitamin E and origin was significant.

CONCLUSION

the sample was composed of 53 women with a mean age of 54.51 ± 4.24 years and BMI of 25.97 ± 5.94 kg/m². In the sociodemographic variables, statistically significant differences in origin, occupation, and income were observed. Daily consumption showed significance for vitamins A, C, and zinc. In adults, vitamins A and C were in accordance with recommendations, while in the elderly a low intake of vitamin E and selenium was observed. The relation between vitamin E and origin was significant.

The Effect of the Mediterranean Diet on Serum Total Antioxidant Capacity in Obese Patients: A Randomized Controlled Trial

OBJECTIVE

The aim of this work was to evaluate the combined effect of physical activity and 1 and 12 months' adherence to Mediterranean diet (MD) on serum total antioxidant capacity (TAC) in obese patients, as well as factors contributing to TAC.

METHODS

One hundred twenty-four patients were randomly assigned to either MD combined with physical activity or standard hypolypemic diet (SHD) with physical activity. Both groups received counseling and education during the initial week and were invited for the follow-up visits, where data on body weight and blood samples were collected. TAC was determined by Trolox equivalent antioxidant capacity and urate was determined using a uricase spectrophotometric method at the initial visit and after 1 and 12 months.

RESULTS

Eighty-four patients finished the 12-month program and were analyzed. The baseline and 1- and 12-month mean (±SD) TAC values in the MD group (n = 40) were 2.38 ± 0.48, 2.51 ± 0.47, and 2.47 ± 0.45 mmol Trolox equivalent (TE)/L, respectively. In the SHD group (n = 44), TAC values were 2.37 ± 0.49, 2.48 ± 0.49, and 2.31 ± 0.51 mmol TE/L, respectively. There was a statistically significant main effect for time (p < 0.001), as well as statistically significant time-diet interaction effect (p = 0.009). There was no statistically significant correlation between TAC and uric acid after 1 month (p = 0.733) or 12 months (p = 0.844) of the intervention. Based on the regression model, which included gender, diet, physical activity level, and percentage body weight change, the type of diet was the only significantly contributing factor to TAC change after the 12-month period, F = 3.867, df = 3, p = 0.012, R = 0.358, R(2) = 0.128.

CONCLUSION

This randomized controlled trial with diet and physical activity intervention and TAC as a primary outcome demonstrated initial antioxidant improvement in both MD and SHD groups and a long-term beneficial effect of MD. The results imply that diet composition-olive oil, nuts, and fish in particular-combined with physical activity modify antioxidant capacity.

Oxidation of olive oil fortified with quercetin, caffeic acid, tyrosol and hydroxytyrosol

Purpose

– This paper aims to evaluate effects of the fortification of polyphenolic compound mixtures of quercetin, caffeic acid, tryrosol and hydroxytyrosol in olive oil oxidation.

Design/methodology/approach

– The authors measured olive oxidation initiated by copper using thiobarbituric acid reactive substance, as an indicator of lipid peroxidation.

Findings

– Overall, most mixture combinations exhibited oxidation similar to olive oil alone. Some mixture combinations of polyphenolic compounds acted as antioxidants; however, as the concentrations were changed, they became prooxidant in nature.

Research limitations/implications

– In vitro studies have limitations for extrapolation to in vivo and clinical studies.

Practical implications

– Such information will be useful in determining optimal concentrations and combinations of antioxidants for reducing rancidity and perhaps as models that could be used to modulate various chronic diseases that are associated with oxidative stress.

Originality/value

– Olive oil, along with fruits, vegetables and fish, are important constituents of health promoting diets, such as the Mediterranean diet. Active ingredients include monounsaturated fatty acids, oleic acid and a variety of antioxidants including various polyphenolic compounds.

Mediterranean diet and incidence of rheumatoid arthritis in women

OBJECTIVE

We examined the association between a Mediterranean dietary pattern, as measured by the Alternate Mediterranean Diet Score (aMed), and risk of incident rheumatoid arthritis (RA) in US women.

METHODS

We prospectively followed 83,245 participants from the Nurses' Health Study (NHS; 1980-2008) and 91,393 participants from NHS II (1991-2009) who were initially free of baseline connective tissue diseases. Dietary information was obtained via validated food frequency questionnaires at baseline and approximately every 4 years during followup. The aMed score was calculated according to the consumption status of 9 food components using cumulative average value. Time-varying Cox proportional hazards models were used to calculate hazard ratios (HRs) for RA, seropositive RA, and seronegative RA after adjustment for potential confounding factors. Results from 2 cohorts were pooled by an inverse variance-weighted, fixed-effects model.

RESULTS

During 3,511,050 person-years of followup, 913 incident cases of RA were documented in the 2 cohorts. After adjustment for several lifestyle and dietary variables, in both cohorts greater adherence to Mediterranean dietary pattern was not significantly associated with altered risk of RA. The pooled HR for women in the highest quartile of the aMed score was 0.98 (95% confidence interval 0.80-1.20) compared with those in the bottom quartile. Similar nonsignificant results were observed for both seropositive and seronegative RA. We did not find significant associations between each individual food component (except for alcohol) of the aMed score and risk of incident RA.

CONCLUSION

We did not find a significant association between a Mediterranean dietary pattern and the risk of RA in women.

Whole-foods, plant-based diet alleviates the symptoms of osteoarthritis

Objective. To evaluate the effectiveness of a whole-foods, plant-based diet (WFPB) to reduce symptoms of osteoarthritis. Methods. Six-week, prospective randomized open-label study of patients aged 19–70 with osteoarthritis. Participants were randomized to a WFPB (intervention) or continuing current diet (control). Outcomes were assessed by mixed models analysis of participant self-assessed weekly SF-36v2 domain t scores, weekly Patient Global Impression of Change (PGIC) scales, and mean weekly Visual Analog Scale (VAS) pain assessment. Mixed models analysis also evaluated pre-post change from baseline level for standard clinical measures: weight, BMI, body temperature, pulse, and blood pressure. Results. Forty participants were randomized. Thirty-seven of them, 18 control and 19 intervention, completed the study. The intervention group reported a significantly greater improvement than the control group in SF-36v2 energy/vitality, physical functioning, role physical, and the physical component summary scale. The differences between the intervention and control PGIC scales were statistically significant over time. Intervention group improvement in VAS weekly mean was also significantly greater than that of the control group from week 2 onward. Conclusion. Study results suggest that a whole-foods, plant-based diet significantly improves self-assessed measures of functional status among osteoarthritis patients.

Fibroblast growth factor 21 (FGF21) ameliorates collagen-induced arthritis through modulating oxidative stress and suppressing nuclear factor-kappa B pathway

It has been demonstrated that circulating FGF21 levels are elevated in the serum and synovial fluid of patients with rheumatoid arthritis (RA). The aim of this study is to investigate efficacy of FGF21 for treatment of RA and the molecular mechanisms of the therapeutic effect on collagen-induced arthritis (CIA). Mice with CIA were subcutaneously administered with FGF21 (5, 2 or 1mg·kg(-1)·d(-1)), IL-1β antibody (5mg·kg(-1)·d(-1)), IL-17A antibody (5mg·kg(-1)·d(-1)) and dexamethasone (DEX) (1mg·kg(-1)·d(-1)), respectively. The effects of treatment were determined by arthritis severity score, histological damage and cytokine production. The activation of NF-κB was analyzed by Western blotting. We also detected the levels of oxidative stress parameters. Our results showed that FGF21 had beneficial effects on clinical symptom and histological lesion of CIA mice. Similar to antibody and DEX, FGF21 treatment alleviated the severity of arthritis by reducing humoral and cellular immune responses and down-regulating the expression of pro-inflammatory cytokines. FGF21 treatment also reduced the expression of TNF-α, IL-1β, IL-6, IFN-γ and MMP-3 and increased level of IL-10 in the spleen tissue or the plasma of CIA mice in a dose-dependent manner. Furthermore, FGF21 inhibited IκBα degradation and NF-κB p65 nuclear translocation and induced significant changes of oxidative stress parameters (MDA, SOD, CAT, GSH-PX and GSH) in the plasma. FGF21 exerts therapeutic efficacy for RA through antioxidant reaction and inhibiting NF-κB inflammatory pathway. This study provides evidence that FGF21 may be a promising therapeutic agent for RA patients.

Muscle wasting in rheumatoid arthritis: The role of oxidative stress

Rheumatoid arthritis (RA), the commonest inflammatory arthritis, is a debilitating disease leading to functional and social disability. In addition to the joints, RA affects several other tissues of the body including the muscle. RA patients have significantly less muscle mass compared to the general population. Several theories have been proposed to explain this. High grade inflammation, a central component in the pathophysiology of the disease, has long been proposed as the key driver of muscle wasting. More recent findings however, indicate that inflammation on its own cannot fully explain the high prevalence of muscle wasting in RA. Thus, the contribution of other potential confounders, such as nutrition and physical activity, has also been studied. Results indicate that they play a significant role in muscle wasting in RA, but again neither of these factors seems to be able to fully explain the condition. Oxidative stress is one of the major mechanisms thought to contribute to the development and progression of RA but its potential contribution to muscle wasting in these patients has received limited attention. Oxidative stress has been shown to promote muscle wasting in healthy populations and people with several chronic conditions. Moreover, all of the aforementioned potential contributors to muscle wasting in RA (i.e., inflammation, nutrition, and physical activity) may promote pro- or anti-oxidative mechanisms. This review aims to highlight the importance of oxidative stress as a driving mechanism for muscle wasting in RA and discusses potential interventions that may promote muscle regeneration via reduction in oxidative stress.