Dietary inflammatory index and risk of multiple sclerosis: Findings from a large population-based incident case–control study

A systematic review and meta-analysis of Dietary Inflammatory Index and the likelihood of multiple sclerosis/ demyelinating autoimmune disease

Diet and inflammation may contribute to the development of multiple sclerosis (MS). The aim of this systematic review and meta-analysis was to assess the association between proinflammatory diet, as estimated by the Dietary Inflammatory Index (DII®), and the likelihood of developing MS or other demyelinating autoimmune diseases. A systematic search was performed of search engines and databases (PubMed, ISI Web of Sciences, Scopus, and Embase) to identify relevant studies before 10th June 2023. The search identified 182 potential studies, from which 39 full-text articles were screened for relevance. Five articles with case-control design (n = 4,322, intervention group: 1714; control group: 2608) met the study inclusion criteria. The exposure variable was DII, with studies using two distinct models: quartile-based comparisons of DII and assessment of continuous DII. The meta-analysis of high versus low quartiles of DII with four effect sizes showed a significant association with MS/demyelinating autoimmune disease likelihood, with an odds ratio (OR) of 3.26 (95% confidence interval (CI) 1.16, 9.10). The meta-analysis of four studies with DII fit as a continuous variable showed a 31% increased likelihood of MS per unit increment; which was not statistically significant at the nominal alpha equals 0.05 (OR 1.31; 95% CI 0.95, 1.81). In conclusion, this systematic review and meta-analysis provides evidence of a positive association between higher DII scores with the likelihood of developing MS, highlighting that diet-induced inflammation could play a role in MS or other demyelinating autoimmune diseases risk.

Association of Pro-Inflammatory Diet, Smoking, and Alcohol Consumption with Bladder Cancer: Evidence from Case-Control and NHANES Studies from 1999 to 2020

BACKGROUND AND PURPOSE

Diet might be a modifiable factor in preventing cancer by modulating inflammation. This study aims to explore the association between the dietary inflammatory index (DII) score and the risk of bladder cancer (BC).

METHODS

A total of 112 BC patients and 292 control subjects were enrolled in a case-control trial. Additionally, we tracked a total of 109 BC patients and 319 controls, whose propensity scores were obtained from the Nutrition Examination Survey (NHANES) database spanning from 1999 to 2020. The baseline index and dietary intake data were assessed using a food frequency questionnaire (FFQ). DII scores were calculated based on the dietary intake of 20 nutrients obtained from participants and categorized into four groups. The association between the inflammatory potential of the diet and BC risk was investigated using multivariate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

High DII scores were associated with a pro-inflammatory diet and a higher risk of BC, with higher DII scores positively associated with a higher risk of BC (quartiles 4 vs. 1, ORs 4.89, 95% CIs 2.09-11.25 p < 0.001). Specifically, this might promote BC development by inducing oxidative stress and affecting DNA repair mechanisms. This result was consistent with the NHANES findings (quartiles 4 vs. 1, ORs 2.69, 95% CIs 1.25-5.77, p = 0.006) and further supported the association of pro-inflammatory diet and lifestyle factors with the risk of BC.

CONCLUSIONS

Diets with the highest pro-inflammatory potential were associated with an increased risk of BC. By adjusting lifestyle factors, individuals might effectively lower their DII, thereby reducing the risk of developing BC. The results are consistent with the NHANES cohort.

Assessment of dietary intake and its inflammatory potential in persons with pediatric-onset multiple sclerosis

OBJECTIVE

To compare diet and the modified dietary inflammatory index (mDII) between individuals with pediatric-onset multiple sclerosis (PoMS), monophasic acquired demyelinating syndromes (monoADS), and controls.

METHODS

The association between diet, mDII, and disease status was examined in 131 individuals with PoMS/monoADS/controls (38/45/48) using logistic regression.

RESULTS

The associations between diet and PoMS were modest, reaching significance for whole grain intake (adjusted odds ratio, aOR=0.964, 95 % confidence intervals, CI:0.934-0.995) but not mDII (aOR=1.20, 95 %CI:0.995-1.46) versus controls. No findings for monoADS reached significance versus controls.

CONCLUSIONS

Individuals with PoMS, but not monoADS, had lower dietary whole grain intake than controls.

Effects of crocin on inflammatory biomarkers and mental health status in patients with multiple sclerosis: A randomized, double-blinded clinical trial

BACKGROUND

Multiple sclerosis (MS), as a demyelinating disease correlated with inflammation and oxidative stress, affects the central nervous system and causes a wide range of complications, including psychiatric disorders. Considering the anti-inflammatory and antioxidant properties associated with the bioactive components of saffron, such as crocin (trans-crocetin bis(β-d-gentiobiosyl) ester), and their potential impact on ameliorating psychiatric symptoms, our study aimed to investigate the effect of crocin on biomarkers of inflammation, oxidative stress, and mental health, e.g., depression and anxiety in individuals with MS.

METHOD

Patients with MS were randomized into two groups, taking either 15 mg crocin tablets twice a day (n = 25; 30 mg/day) or placebo tablets (n = 25) for 8 weeks. The valid and reliable Beck depression and anxiety scale questionnaire was recorded, and fasting blood samples were collected to measure biomarkers, including high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), and nitric oxide (NO) at baseline and week 8 following the intervention.

RESULTS

The data analysis using ANCOVA showed that supplementation with crocin for 8 weeks significantly lowered hs-CRP levels (p-value= 0.01). In addition, within-group comparisons showed crocin significantly decreased anxiety (p-value= 0.01). However, crocin did not affect serum MDA and NO after 8 weeks of intervention.

CONCLUSION

Our findings suggest that crocin may keep promise in attenuating inflammation, evidenced by reducing hs-CRP in patients with MS. However, supplementation for 8 weeks may not be sufficient to improve mental health, and future clinical studies with higher sample sizes and various doses and durations are recommended.

Association between dietary inflammatory index and risk of demyelinating autoimmune diseases

Background: Considering limited data on the association between dietary inflammatory index (DII) and demyelinating autoimmune diseases, here, we studied this issue in the early diagnosed patients [e.g., preceding Multiple Sclerosis (MS) diagnosing level (Clinically Isolated Syndrome (CIS), and Radiologically Isolated Syndrome (RIS), MS, and Neuromyelitis Optica Spectrum Disorder (NMOSD)] using a case-control study among the Iranian population. Methods: A total of 291 subjects were selected as the cases (Patients with demyelinating autoimmune diseases including CIS, RIS, MS, and NMOSD, who were diagnosed less than six months before recruitment) and 297 others as controls. A 117-item semi-quantitative food frequency questionnaire (FFQ) was obtained from all of the participants and DII was calculated. Results: After controlling for potential confounders, adherence to a pro-inflammatory diet was associated with a higher risk of demyelinating autoimmune diseases (OR=2.05, 95% CI: 0.51, 3.58), EDSS (OR=2.02, 95% CI: 0.51, 3.53), active plaque (OR=1.90, 95% CI: 0.08, 3.71), higher lesion load (OR=2.11, 95% CI: 0.58, 3.64), LETM (OR=2.19, 95% CI: 0.27, 4.11), higher number of plaques (OR=2.11, 95% CI: 0.58, 3.64), and brain atrophy (OR=2.12, 95% CI: 0.57, 3.67). Conclusion: Our study suggests a possible link between the inflammatory potential of the diet and demyelinating autoimmune disease; however, further prospective cohort studies are needed to draw a causal link on this issue.

Dietary inflammatory index and neuropsychiatric disorders

Neuropsychiatric disorders (NPDs) are considered a potential threat to mental health. Inflammation predominantly plays a role in the pathophysiology of NPDs. Dietary patterns are widely postulated to be involved in the physiological response to inflammation. This review aims to discuss the literature on how dietary inflammatory index (DII) is related to inflammation and, consequently, NPDs. After comprehensive scrutiny in different databases, the articles that investigated the relation of DII score and various NPDs and psychological circumstances were included. The association between dietary patterns and mental disorders comprising depression, anxiety, and stress proved the role of a proinflammatory diet in these conditions' exacerbation. Aging is another condition closely associated with DII. The impact of proinflammatory and anti-inflammatory diet on sleep quality indicated related disorders like sleep latency and day dysfunctions among the different populations are in relation with the high DII score. The potential effects of genetic backgrounds, dietary patterns, and the gut microbiome on DII are discussed as well. To plan preventive or therapeutic interventions considering the DII, these factors, especially genetic variations, should be considered as there is a growing body of literature indicating the role of personalized medicine in different NPDs. To the best of our knowledge, there is a limited number of RCTs on this subject, so future research should evaluate the causality via RCTs and look for therapeutic interventions with an eye on personalized medicine using information about DII in NPDs.

Additive interaction between dietary inflammatory index and some key risk factors of multiple sclerosis: a population-based incident case-control study

BACKGROUND

Recently, dietary inflammatory index (DII) has been introduced as a significant risk factor for MS. We examined the interaction between dietary inflammatory index and some formerly demonstrated key risk factors of multiple sclerosis (MS).

MATERIAL AND METHODS

We conducted a population-based incident case-control study of 547 MS cases and 1057 controls. Multiplicative and additive interaction were assessed using interaction term in the logistic regression model and synergy index (SI), respectively.

RESULTS

Additive interaction was detected between DII and drug abuse (SI = 2.58; 95% CI: 1.14-5.82), gender (SI = 2.00; 95% CI: 1.39-2.87) and history of depression (SI = 1.68; 95% CI: 1.04-2.72) on the risk scale. The risk of MS in drug abusers with DII ≥ 0 was 10.4-times higher than that in non-drug abusers with DII < 0 (OR = 10.4, 95% CI: 5.12-21.02, P < 0.001). We also found that women with DII ≥ 0 had a 9.2 times larger risk compared with the men with DII < 0(OR = 9.2, 95% CI: 6.3-13.5, P < 0.001). Similarly, the risk of MS was remarkably higher in those with a history of depression and DII >0 (OR = 7.6, 95% CI: 5.1-11.5, P < 0.001). There was no evidence of multiplicative interaction between DII and the other risk factors of MS on the risk scale.

CONCLUSIONS

We identified additive interaction between DII and drug abuse, gender and history of depression on MS. Further studies are needed to understand the underlying mechanisms of these detected interactions.

Nutritional Support During Long COVID: A Systematic Scoping Review

Introduction: Long COVID is a term that encompasses a range of signs, symptoms, and sequalae that continue or develop after an acute COVID-19 infection. The lack of early recognition of the condition contributed to delays in identifying factors that may contribute toward its development and prevention. The aim of this study was to scope the available literature to identify potential nutritional interventions to support people with symptoms associated with long COVID. Methods: This study was designed as a systematic scoping review of the literature (registration PROSPERO CRD42022306051). Studies with participants aged 18 years or older, with long COVID and who underwent a nutritional intervention were included in the review. Results: A total of 285 citations were initially identified, with five papers eligible for inclusion: two were pilot studies of nutritional supplements in the community, and three were nutritional interventions as part of inpatient or outpatient multidisciplinary rehabilitation programs. There were two broad categories of interventions: those that focused on compositions of nutrients (including micronutrients such as vitamin and mineral supplements) and those that were incorporated as part of multidisciplinary rehabilitation programs. Nutrients included in more than one study were multiple B group vitamins, vitamin C, vitamin D, and acetyl-l-carnitine. Discussion: Two studies trialed nutritional supplements for long COVID in community samples. Although these initial reports were positive, they are based on poorly designed studies and therefore cannot provide conclusive evidence. Nutritional rehabilitation was an important aspect of recovery from severe inflammation, malnutrition, and sarcopenia in hospital rehabilitation programs. Current gaps in the literature include a potential role for anti-inflammatory nutrients such as the omega 3 fatty acids, which are currently undergoing clinical trials, glutathione-boosting treatments such as N-acetylcysteine, alpha-lipoic acid, or liposomal glutathione in long COVID, and a possible adjunctive role for anti-inflammatory dietary interventions. This review provides preliminary evidence that nutritional interventions may be an important part of a rehabilitation program for people with severe long COVID symptomatology, including severe inflammation, malnutrition, and sarcopenia. For those in the general population with long COVID symptoms, the role of specific nutrients has not yet been studied well enough to recommend any particular nutrient or dietary intervention as a treatment or adjunctive treatment. Clinical trials of single nutrients are currently being conducted, and future systematic reviews could focus on single nutrient or dietary interventions to identify their nuanced mechanisms of action. Further clinical studies incorporating complex nutritional interventions are also warranted to strengthen the evidence base for using nutrition as a useful adjunctive treatment for people living with long COVID.

Impact of Alcohol Consumption on Multiple Sclerosis Using Model-based Standardization and Misclassification Adjustment Via Probabilistic Bias Analysis

BACKGROUND

The etiology of multiple sclerosis (MS) is still not well-demonstrated, and assessment of some risk factors like alcohol consumption has problems like confounding and measurement bias. To determine the causal effect of alcohol consumption on MS after adjusting for alcohol consumption misclassification bias and confounders.

METHODS

In a population-based incident case-control study, 547 patients with MS and 1057 healthy people were recruited. A minimally sufficient adjustment set of confounders was derived using the causal directed acyclic graph. The probabilistic bias analysis method (PBAM) using beta, logit-logistic, and triangular probability distributions for sensitivity/specificity to adjust for misclassification bias in self-reporting alcohol consumption and model-based standardization (MBS) to estimate the causal effect of alcohol consumption were used. Population attributable fraction (PAF) estimates with 95% Monte Carlo sensitivity analysis (MCSA) intervals were calculated using PBAM and MBS analysis. Bootstrap was used to deal with random errors.

RESULTS

The adjusted risk ratio (95% MCSA interval) from the probabilistic bias analysis and MBS between alcohol consumption and MS using the three distribution was in the range of 1.93 (1.07 to 4.07) to 2.02 (1.15 to 4.69). The risk difference (RD) in all three scenarios was 0.0001 (0.0000 to 0.0005) and PAF was in the range of 0.15 (0.010 to 0.50) to 0.17 (0.001 to 0.47).

CONCLUSION

After adjusting for measurement bias, confounding, and random error alcohol consumption had a positive causal effect on the incidence of MS.

Dietary Patterns and Their Associations with Symptom Levels Among People with Multiple Sclerosis: A Real-World Digital Study

INTRODUCTION

The objective of the study was to investigate long-term food intake patterns and establish possible associations between the inferred dietary habits and levels of reported symptoms among people with multiple sclerosis (MS) in Denmark.

METHODS

The present study was designed as a prospective cohort study. Participants were invited to register daily food intake and MS symptoms and were observed during a period of 100 days. Dropout and inclusion probabilities were addressed using generalized linear models. Dietary clusters were identified among 163 participants using hierarchical clustering on principal component scores. Associations between the dietary clusters and the levels of self-assessed MS symptoms were estimated using inverse probability weighting. Furthermore, the effect of a person's position on the first and second principal dietary component axis on symptom burden was investigated.

RESULTS

Three dietary clusters were identified: a Western dietary cluster, a plant-rich dietary cluster and a varied dietary cluster. Analyses further indicated a vegetables-fish-fruit-whole grain axis and a red-meat-processed-meat axis. The plant-rich dietary cluster showed reduction in symptom burden in nine pre-defined MS symptoms compared to the Western dietary cluster (between 19 and 90% reduction). This reduction was significant for pain and bladder dysfunction as well as across all nine symptoms (pooled p value = 0.012). Related to the two dietary axes, high intake of vegetables resulted in 32-74% reduction in symptom burden compared to low levels of vegetable intake. Across symptoms, this was significant (pooled p value = 0.015), also regarding walking difficulty and fatigue.

CONCLUSIONS

Three dietary clusters were identified. Compared to levels of self-assessed MS-related symptoms, and adjusted for potential confounders, the results suggested less symptom burden with increased intake of vegetables. Although the research design limits the possibilities of establishing causal inference, the results indicate that general guidelines for healthy diet may be relevant as a tool in coping with MS symptoms.

Environmental Influences on Risk and Disease Course in Pediatric Multiple Sclerosis

Pediatric multiple sclerosis (MS) accounts for 3%-10% of all patients diagnosed with MS. Complex interplay between environmental factors impacts the risk for MS and may also affect disease course. Many of these environmental factors are shared with adult-onset MS. However, children with MS are in closer temporal proximity to the biological onset of MS and have less confounding environmental exposures than their adult counterparts. Environmental factors that contribute to MS risk include: geographical latitude, viral exposures, obesity, vitamin deficiencies, smoking, air pollution, perinatal factors, gut microbiome, and diet. More recently, research efforts have shifted to studying the impact of these risk determinants on the clinical course of MS. In this article we will examine relevant environmental risk determinants of pediatric MS and review the current knowledge on how these factors may contribute to pediatric MS disease evolution.

Multiple Sclerosis-Related Dietary and Nutritional Issues: An Updated Scoping Review with a Focus on Pediatrics

PURPOSE

Lifestyle/dietetic habits play an important role in the development and progression of multiple sclerosis (MS) disease. Here, we examine the basic pathomechanisms underlying intestinal and brain barrier modifications in MS and consider diets and dietary supplementations proposed over time to complement pharmacological therapies for improving disease outcome both in adults and in children.

METHODS

Scoping literature search about evidence-based findings in MS-related gut-brain axis (GBA) pathophysiology and nutritional issues at all ages.

FINDINGS

Data show that (1) no universal best diet exists, (2) healthy/balanced diets are, however, necessary to safeguard the adequate intake of all essential nutrients, (3) diets with high intakes of fruits, vegetables, whole grains, and lean proteins that limit processed foods, sugar, and saturated fat appear beneficial for their antioxidant and anti-inflammatory properties and their ability to shape a gut microbiota that respects the gut and brain barriers, (4) obesity may trigger MS onset and/or its less favorable course, especially in pediatric-onset MS. Vitamin D and polyunsaturated fatty acids are the most studied supplements for reducing MS-associated inflammation.

CONCLUSIONS

Pending results from other and/or newer approaches targeting the GBA (e.g., pre- and probiotics, engineered probiotics, fecal-microbiota transplantation), accurate counseling in choosing adequate diet and maintaining physical activity remains recommended for MS prevention and management both in adults and children.

Feeding the gut microbiome: impact on multiple sclerosis

Multiple sclerosis (MS) is a multifactorial neurological disease characterized by chronic inflammation and immune-driven demyelination of the central nervous system (CNS). The rising number of MS cases in the last decade could be partially attributed to environmental changes, among which the alteration of the gut microbiome driven by novel dietary habits is now of particular interest. The intent of this review is to describe how diet can impact the development and course of MS by feeding the gut microbiome. We discuss the role of nutrition and the gut microbiota in MS disease, describing preclinical studies on experimental autoimmune encephalomyelitis (EAE) and clinical studies on dietary interventions in MS, with particular attention to gut metabolites-immune system interactions. Possible tools that target the gut microbiome in MS, such as the use of probiotics, prebiotics and postbiotics, are analyzed as well. Finally, we discuss the open questions and the prospects of these microbiome-targeted therapies for people with MS and for future research.

Overview of diet and autoimmune demyelinating optic neuritis: a narrative review

This review summarizes the cellular and molecular underpinnings of autoimmune demyelinating optic neuritis (ADON), a common sequela of multiple sclerosis and other demyelinating diseases. We further present nutritional interventions tested for people with multiple sclerosis focusing on strategies that have shown efficacy or associations with disease course and clinical outcomes. We then close by discuss the potential dietary guidance for preventing and/or ameliorating ADON.

Efficacy of Diet on Fatigue and Quality of Life in Multiple Sclerosis: A Systematic Review and Network Meta-analysis of Randomized Trials

BACKGROUND AND OBJECTIVE

Emerging evidence suggests a role for diet in multiple sclerosis (MS) care; however, owing to methodological issues and heterogeneity of dietary interventions in preliminary trials, the current state of evidence does not support dietary recommendations for MS. The objective of this study was to assess the efficacy of different dietary approaches on MS-related fatigue and quality of life (QoL) through a systematic review of the literature and network meta-analysis (NMA).

METHODS

Electronic database searches were performed in May 2021. Inclusion criteria were (1) randomized trial with a dietary intervention, (2) adults with definitive MS based on McDonald criteria, (3) patient-reported outcomes for fatigue and/or QoL, and (4) minimum intervention period of 4 weeks. For each outcome, standardized mean differences (SMDs) were calculated and included in random effects NMA to determine the pooled effect of each dietary intervention relative to each of the other dietary interventions. The protocol was registered at PROSPERO (CRD42021262648).

RESULTS

Twelve trials comparing 8 dietary interventions (low-fat, Mediterranean, ketogenic, anti-inflammatory, Paleolithic, fasting, calorie restriction, and control [usual diet]), enrolling 608 participants, were included in the primary analysis. The Paleolithic (SMD -1.27; 95% CI -1.81 to -0.74), low-fat (SMD -0.90; 95% CI -1.39 to -0.42), and Mediterranean (SMD -0.89; 95% CI -1.15 to -0.64) diets showed greater reductions in fatigue compared with control. The Paleolithic (SMD 1.01; 95% CI 0.40-1.63) and Mediterranean (SMD 0.47; 95% CI 0.08-0.86) diets showed greater improvements in physical QoL compared with control. For improving mental QoL, the Paleolithic (SMD 0.81; 95% CI 0.26-1.37) and Mediterranean (SMD 0.36; 95% CI 0.06-0.65) diets were more effective compared with control. However, the NutriGRADE credibility of evidence for all direct comparisons is very low because of most of the included trials having high or moderate risk of bias, small sample sizes, and the limited number of studies included in this NMA.

DISCUSSION

Several dietary interventions may reduce MS-related fatigue and improve physical and mental QoL; however, because of the limitations of this NMA, which are driven by the low quality of the included trials, these findings must be confirmed in high-quality, randomized, controlled trials.

Diet-related inflammation increases the odds of multiple sclerosis: Results from a large population-based prevalent case-control study in Jordan

Background

Multiple sclerosis, a chronic inflammatory disease in young and middle-aged adults, is one of the leading causes of non-traumatic disability in adults. Diet is known to have an important role in the modulating inflammatory processes and influencing molecular pathways.

Purpose

This study aims to examine the association of the inflammatory capacity of diet measured by DII with MS in Jordan.

Methods

This prevalent case-control study included participants of both sexes, aged between 20 and 60 years. The cases (n = 541) had a confirmed diagnosis of prevalent Multiple Sclerosis (MS) in the previous 3 years, and controls (n = 607) were apparently healthy individuals matched on sex and age (42 ± 4 years). A validated Arabic food frequency questionnaire (FFQ) was utilized to obtain estimated dietary intake. Dietary data from the FFQ were analyzed using ESHA's Food Processor^® nutrition analysis software, and the results were used to calculate the DII scores. Logistic regression analyses, controlling for covariates such as age, sex, body mass index, and smoking status, were used to measure the association between DII score and MS outcomes.

Results

Cases represent a mixed sample of MS phenotypes and controls were comparable on age and sex. However, controls tended to be taller, lighter, had a lower BMI, and had a lower smoking rate. After controlling for age, BMI, sex, and smoking status, there was a consistent increase in MS risk according to DII score, with a 10-fold increase in odds in quartile 4 vs. quartile 1 [OR_{quartile 4vs1} = 10.17 (95% CI: 6.88; 15.04)]. For each point increase in DII score, there was nearly a doubling of odds [OR₁ = 1.75 (95% CI: 1.59; 1.92)]. Individual nutrients and food values aligned according to their contribution to the DII score calculations.

Conclusion

The findings of this study, obtained in MS patients with varied illness duration over the previous 3 years, are consistent with an association between the overall inflammatory potential of diet and MS odds. Our findings among MS participants showed a significantly more pro-inflammatory DII scores than age- and sex-matched controls. Our results also suggest that MS group had a diet rich in pro-inflammatory foods and nutrients.

Facilitators of and Barriers to Adherence to Dietary Interventions Perceived by Women With Multiple Sclerosis and Their Support Persons

Background:

People with multiple sclerosis (MS) frequently report implementing dietary strategies as part of their personal wellness programs; however, little is known about the perceived themes of healthy behavior change in people with MS.

Methods:

Semistructured one-on-one interviews were conducted with 20 women with MS enrolled in 2 different restrictive dietary intervention studies and their 18 self-identified support persons consisting of partners and adult children. Interviews were transcribed, coded, categorized, and then grouped into summative themes. The frequency of issues being mentioned as facilitators of or barriers to diet adherence was evaluated to identify possible differences in perceived experiences between women with MS and their support persons during the studies.

Results:

Five qualitative themes were identified: (1) personal motivation, (2) diet components, (3) time, (4) support, and (5) resource access. Major facilitators of dietary adherence were positive support from support persons and study staff, access to resources, symptom improvement, and personal motivation. Major barriers included the novelty of the study diet, lack of cooking skills, no change in or worsening of symptoms, lack of diet knowledge, and food preferences and temptations. Symptom severity was more frequently reported as a barrier to study diet adherence among participants with secondary progressive MS.

Conclusions:

Methods to enhance personal motivation and ensure positive support from support persons and study staff may improve study diet adherence. Due to the unique challenges faced by people with MS, future studies should tailor interventions to their unique MS cohort to increase diet adherence.

Joint Waterpipe and Cigarette Smoking as Key Correlate of History of Depression in Iranian Population: A Cross-Sectional Study

Research on the association between waterpipe smoking and depression is limited. This study aimed to explore the prevalence and adjusted associated correlates of depression among Iranian adult. We analyzed data from 974 participants of a population-based cross-sectional study enrolling 18-50-year-old residents of Tehran, Iran in 2015. Data on lifetime self-reported history of depression, smoking behaviors, socioeconomic status, self-rated health, physical activity, stressful life events as well as a number of relevant confounders was obtained. Logistic regression models were employed for estimating adjusted odds ratios (ORs) and their 95% confidence intervals (CI). The mean (SD) age of the study sample was 32.55 (8.58) years. Of 974 recruited adults, 52.36% were female. The lifetime prevalence of depression in the general population was 17.0%. In general, 21.77% and 24.79% of participant reported lifetime history of cigarette and waterpipe smoking, respectively. While only cigarette smoking (OR = 1.94, 95% CI: (1.04-3.61) and only waterpipe smoking (OR = 1.65, 95% CI: (.95-2.86) were significantly associated with depression, joint cigarette and waterpipe smoking (OR= 3.76, 95% CI: (1.99-6.08) was the strongest correlate of depression followed by female gender (OR = 3.28, 95% CI: (2.08-5.15) and poor self-rated health (OR = 2.47, 95% CI: (1.73-3.53). The prevalence of self-reported depression in general population of Tehran is considerably higher than its global mean. We reported joint cigarette and waterpipe smoking as a significant correlate with depression in the general population. Future health promotion interventions should highlight the disadvantages of joint cigarette and waterpipe smoking targeting adults and especially females.

Association of Dietary Inflammatory Index (DII) and depression in the elderly over 55 years in Northern China: analysis of data from a multicentre, cohort study

OBJECTIVES

Our study aimed to assess the association between the Dietary Inflammatory Index (DII) and depression in the elderly over 55 years in Northern China.

METHODS

We analysed the data of 2022 Chinese adults aged 55 and over from a community-based neurological disease cohort study from 2018 to 2019. A validated semiquantitative food frequency questionnaire was used to assess eating habits at the time of inclusion. Multiple logistic regression was used for analysis, and social demographics, lifestyle and health-related factors were adjusted.

RESULTS

Among the included population, the prevalence of depression was 23.39%. Mean (SD) and range of the DII in the included population were 1.70 (1.42) and -5.20 to +5.68. The risk of depression was significantly higher in participants in the most pro-inflammatory group (quartile 4) than in the participants in the most anti-inflammatory group (quartile 1) (OR 1.53; 1.37 to 1.82; p-trend=0.01). The subgroup analysis of body mass index (BMI) showed that there is a significant association between DII and the risk of depression in overweight and obese people (p＜0.05). The restricted cubic spline results show that the OR value of depression possesses an upward trend with the increase of the DII score.

CONCLUSIONS

Aged patients with depression present a higher potential for dietary inflammation. Pro-inflammatory diets might increase the risk of depressive symptoms. Further research in different populations is crucial to confirm the association between DII and depression.

A proinflammatory diet is associated with an increased likelihood of first clinical diagnosis of central nervous system demyelination in women

BACKGROUND

While a number of studies have examined associations between dietary factors and risk of multiple sclerosis (MS), little is known about intakes of inflammation-modulating foods and nutrients and risk of MS.

OBJECTIVES

To test associations between the Dietary Inflammatory Index (DII®) and risk of a first clinical diagnosis of central nervous system (CNS) demyelination (FCD) (267 cases, 507 controls) using data from the Ausimmune Study.

METHODS

The 2003-2006 Ausimmune Study was a multicentre, matched, case-control study examining environmental risk factors for an FCD, a common precursor to MS. The DII is a well-recognised tool that categorises individuals' diets on a continuum from maximally anti-inflammatory to maximally pro-inflammatory. The DII score was calculated from dietary intake data collected using a food frequency questionnaire. Conditional logistic regression models were used to estimate the association between DII and FCD separately for men and women.

RESULTS

In women, a higher DII score was associated with increased likelihood of FCD, with a 17% increase in likelihood of FCD per one-unit increase in DII score (adjusted odds ratio 1.17, 95% confidence interval 1.04-1.33). There was no association between DII and FCD in men (adjusted odds ratio 0.88, 95% confidence interval 0.73-1.07).

CONCLUSIONS

These findings suggest that a pro-inflammatory diet is associated with an increased likelihood of FCD in women.

Investigating Associations Between Depressive Symptoms and Anti-/Pro-Inflammatory Nutrients in an Elderly Population in Northern China: A Bayesian Kernel Machine Regression Approach

Backgroud

The potential for dietary inflammation has been shown to be associated with a variety of chronic diseases. The relationship between the potential for dietary inflammation and depression in the elderly is unclear.

Objective

This study aimed to exam the relationship between different nutrients and the risk of depression symptoms in the elderly.

Methods

In total, 1865 elderly in northern China were investigated at baseline from 2018 to 2019 and followed up in 2020. We measured the baseline intake of 22 nutrients and used Least Absolute Shrinkage and Selection Operator(LASSO) regression analysis and Bayesian Kernel Machine Regression (BKMR) to explore the association between exposure to a variety of nutrients with different inflammatory potentials and the risk of depressive symptoms.

Results

A total of 447 individuals (24.0%) were diagnosed with depressive symptoms. Through the lasso regression model, it was found that 11 nutrients are significantly related to the risk of depressive symptoms, of which 6 nutrients are pro-inflammatory nutrients (inflammation effect score>0), and 5 are anti-inflammatory nutrients (inflammation effect score<0). We incorporated the inflammatory effect scores of 11 nutrients into the BKMR model at the same time, and found that the overall inflammatory effect of 11 nutrients increased with the increase of total inflammatory scores, suggesting that the overall effect was pro-inflammatory. BKMR subgroup analysis shows that whether in the pro-inflammatory nutrient group or the anti-inflammatory nutrient group, multiple nutrients have a significant combined effect on depressive symptoms. By comparing the overall and group effects, we found that the inflammatory effects of the pro-inflammatory diet and the anti-inflammatory diet in the study’s diet are offset by each other (P<0.005).

Conclusion

We determined the combined effect of multiple nutrients of different inflammatory potential classifications on depressive symptoms in the elderly.

Dietary risk factors of primary progressive multiple sclerosis: A population-based case-control study

OBJECTIVES

There are growing evidences on the role of nutritional factors in multiple sclerosis (MS) occurrence. But dietary data are limited in primary progressive type of MS (PPMS). We assessed the role of dietary factors during adolescence in PPMS risk.

METHODS

An incident case-control study on 143 PPMS cases with definite diagnosis and 400 controls were conducted in Sina hospital, Tehran, Iran. Demographic data were collected. Data on nutritional habits during adolescence were obtained using questionnaire designed for multinational case-control studies of environmental risk factors for multiple sclerosis (EnvIMS-Q). Logistic regression models were run to evaluate the role of diet in PPMS risk.

RESULTS

A significant association was founded between higher intake of dairy, seafood, red meat, poultry, vegetable, fruit and nut and lower risk of PPMS (P< 00.5). This association was dose dependent for all mentioned food groups except fruit. In the fully adjusted model, more intake of dairy (OR: 0.27; 95%CI: 0.14-0.53), seafood (OR: 0.21; 95%CI: 0.10-0.44), red meat (OR:0.44; 95%CI: 0.22-0.90), vegetable (OR: 0.19; 95%CI: 0.09-0.39), fruit (OR: 0.47; 95%CI: 0.22-0.99) and nut (OR: 0.29; 95%CI: 0.15-0.56) in the third tertiles resulted in significant reduction in PPMS risk. In case of poultry consumption, the association was meaningful just in the third tertile of crude model (OR: 0.54; 95%CI: 0.30-0.95). Nutrient supplementation with calcium, iron, folic acid, vitamin B12 and C were also related with more than 84% lower risk of PPMS.

CONCLUSION

Our data proposed that adequate intake of food groups and nutrient supplementation during adolescence may be effective in reducing adult-onset PPMS risk.

The relationship between Dietary Inflammatory Index and disease severity and inflammatory status: a case-control study of COVID-19 patients

Numerous studies have revealed strong relationships between COVID-19 and inflammation. However, the imminent link between diet-related inflammation and the COVID-19 risk has not been addressed before. So, we explored the capability of the Energy-Adjusted Dietary Inflammatory Index (E-DII) to predict the inflammatory markers, incidence and severity of COVID-19. We conducted a case-control study consisting of 120 adults; they had been admitted for COVID-19 at hospital during June and July, 2020. The E-DII score was calculated based on the dietary intake, which was evaluated by a 138-item semi-quantitative food frequency questionnaire. Serum levels of inflammatory markers including the Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and White blood cells (WBCs) differential were measured. Severity of disease was assessed by chest radiology criteria. Patients with the maximum pro-inflammatory energy adjusted E-DII score had 7·26 times greater odds of developing COVID-19, as compared to those in tertiles 1 (E-DII _T3v. E-DII _T1: OR = 7·26; 95 % CI 2·64 to 9·94, P < 0·001). Also, a positive association between E-DII and C-reactive protein (CRP) was observed (B_E-DII = 1·37, 95 % CI 0·72, 2·02), such that with each unit increase in E-E-DII, the CRP levels were increased by 1·37 units. Furthermore, a significant association was found between E-DII and the severity of disease (B_E-DII = 0·03, 95 % CI 0·01, 0·06. 0·024). Patients consuming a diet with a higher pro-inflammatory potential were at a greater risk of COVID-19 occurrence; also, the severity of disease was elevated with a high score inflammatory diet.

Modified Mediterranean Diet VS. Traditional Iranian Diet: Efficacy of Dietary Interventions on Dietary Inflammatory Index Score, Fatigue Severity and Disability in Multiple Sclerosis Patients

BACKGROUND

Current evidence suggests that adherence to the Mediterranean Diet (MeD) can reduce inflammation in chronic diseases; however, studies pertaining to Relapsing-Remitting Multiple Sclerosis (RRMS) are limited. Therefore, the aim of this study was to investigate the potential of the modified MeD (mMeD) in improving Dietary Inflammatory Index (DII) scores, disability, and fatigue severity, compared to Traditional Iranian Diet (TID), in RRMS patients.

METHODS

After initial screening (n=261), 180 RRMS patients were randomized to receive mMeD or TID (as control) for six months. DII score, Expanded Disability Status Scale (EDSS) and 21-item Modified Fatigue Impact Scale (MFIS) were evaluated at baseline and trial cessation. Multivariate analysis of covariance was conducted and adjusted for age, gender, body weight, body mass index, education level, supplement use, family history and duration of MS.

RESULTS

Of the 180 patients enrolled, 147 participants were included in the final analysis (n of mMeD=68; n of TID=79). Self-reported adherence was good (˜81%). Dietary intakes of 45 food parameters were assessed through the food frequency questionnaire. The mMeD significantly reduced DII scores after six months (2.38±0.21 to -1.87±0.86, P<0.001), but TID did not elicit any changes (2.21±0.44 to 2.14±1.01, P=0.771). Additionally, MFIS total score decreased significantly (72.4±17.2 to 63.9±14.2, P<0.001), whereas there was no considerable improvement for EDSS in the mMeD group.

CONCLUSION

Adherence to mMeD, for six months, improved dietary inflammatory status and fatigue severity in RRMS patients, however, the traditional Iranian diet did not positively impact dietary inflammation and MFIS score.

Estimating the Marginal Causal Effect and Potential Impact of Waterpipe Smoking on Risk of Multiple Sclerosis Using the Targeted Maximum Likelihood Estimation Method: A Large, Population-Based Incident Case-Control Study

There are few if any reports regarding the role of lifetime waterpipe smoking in the etiology of multiple sclerosis (MS). In a population-based incident case-control study conducted in Tehran, Iran, we investigated the association between waterpipe smoking and MS, adjusted for confounders. Cases (n = 547) were patients aged 15-50 years identified from the Iranian Multiple Sclerosis Society between 2013 and 2015. Population-based controls (n = 1,057) were persons aged 15-50 years recruited through random digit telephone dialing. A doubly robust estimation method, the targeted maximum likelihood estimator (TMLE), was used to estimate the marginal risk ratio and odds ratio for the association between waterpipe smoking and MS. The estimated risk ratio and odds ratio were both 1.70 (95% confidence interval: 1.34, 2.17). The population attributable fraction was 21.4% (95% confidence interval: 4.0, 38.8). Subject to the limitations of case-control studies in interpreting associations causally, these results suggest that waterpipe use, or strongly related but undetermined factors, increases the risk of MS. Further epidemiologic studies, including nested case-control studies, are needed to confirm these findings.

"Association between dietary inflammatory index (DII) and risk of irritable bowel syndrome: a case-control study"

Background

Pathophysiology of IBS is not well recognized; however, several studies have shown the possible relationship between diet and risk of IBS. We assessed the ability of the dietary inflammatory index (DII) to predict the risk of IBS.

Methods

The subjects were 155 IBS cases and 310 age- and sex-matched healthy controls (aged ≥18 years). The participants were recruited from June, 2019 to March, 2020. IBS was recognized using the Rome IV criteria. DII score was computed based on dietary intake using a 168-item FFQ. The DII score was calculated based on energy-adjusted amounts of nutrients using residual method. Logistic regression models were used to estimate multivariable odds ratios (ORs).

Results

The mean DII score was significantly higher among IBS patients in comparison to healthy controls (0.78 ± 2.22 vs. − 0.39 ± 2.27). In crude model, increase in DII as continuous variable was associated with a significant increase in the risk of IBS (OR (95% CI): 1.26 (1.1–15.38)). Furthermore, the association remained significant even after adjusting for age and sex (OR (95% CI): 1.28 (1.1–17.41)) and after multivariate adjustment (OR (95% CI): 1.38 (1.2–1.56)). In crude, age and sex adjusted and multivariate-adjusted models subjects in fourth quartile of DII had higher OR in comparison to subjects in first quartile.

Conclusions

This study showed a possible positive association between a pro-inflammatory diet and the risk of IBS. Thus, encouraging intake of more anti-inflammatory dietary factors and reducing intake of pro-inflammatory factors may be a strategy for reducing risk of IBS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00721-5.

Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases? A systematic narrative review

Respiratory Viruses infections (RVI) such as rhinovirus, coronavirus, influenza virus, and adenovirus affect the respiratory and the immune systems. The role of nutrition in the respiratory and immune systems has been studied in some studies, and its importance is undeniable. In addition, one of the key findings in this disease is high inflammation that affects almost all patients. This systematic narrative review aims to answer the question, "Can an anti-inflammatory diet be effective in preventing or treating viral respiratory diseases?" A systematic review search was used for the articles extraction. All studies published in English from 1999 to 2020 investigating dietary inflammatory conditions and RVI were included. Food items with anti-inflammatory properties were selected based on the definition of the dietary inflammatory index (DII). We used Google Scholar, Pub Med, Scopus, Web of Science, Springer, Science Direct, Directory of Open Access Journals, Elsevier, Taylor and Francis, ProQuest, EBSCO, MEDLINE, and SciELO databases for extracting articles. Keywords were restricted by DII. Based on DII, food items/nutrients are involved in inflammation, some of which have anti-inflammatory and some inflammatory properties. Some foods/nutrients, in addition to their anti-inflammatory properties, have antioxidant, antiviral, and immune-enhancing properties. Considering the immune system's involvement, increased inflammation, and involvement of the pulmonary system in RVI and the remarkable role of the anti-inflammatory foods for counteracting them, it is recommended to use a predominantly anti-inflammatory diet along with prevention/control and treatment protocols. An anti-inflammatory diet (based on DII) includes turmeric, ginger, garlic, onions, saffron, dietary vitamin C, vitamin D, zinc, and omega-3 are recommended to reduce infection symptoms and duration.

Maternal education has significant influence on progression in multiple sclerosis

OBJECTIVE

The identification of potential risk factors for disease severity is of great importance in the treatment of multiple sclerosis. The influence of socioeconomic status on progression in multiple sclerosis (MS) is sparsely investigated. Our aim was to investigate how socioeconomic status in adolescence influences disease progression in later life.

METHODS

A total of 1598 patients with multiple sclerosis from a well-defined population in Norway were included. Detailed information on disease progression, measured by expanded disability status scale (EDSS) and multiple sclerosis severity score (MSSS), were combined with data on socioeconomic factors. We used residency and parental level of education at patients' age 16 and exposure to second-hand smoking as a measure of socioeconomic status in adolescence, adjusting for the same variables as well as use of disease modifying treatments at prevalence date 01.01.18.

RESULTS

High maternal level of education at patients' age 16 was significantly associated with less pronounced disease progression measured by MSSS (β-coefficient -0.58, p = 0.015), younger age and lower EDSS at disease onset, and shorter time from onset to diagnosis. No significant associations were found for paternal education level and MSSS. The use of any disease modifying treatment before prevalence date was significantly associated with disease progression (β-coefficient -0.49, p=0.004), while residence, current and second-hand smoking were not.

CONCLUSION

This study on a population-based, real-world cohort shows that the parental level of education has a significant impact on a timely diagnosis of MS. In addition to disease modifying treatment, maternal level of education also had an impact on disease progression in later life.

Adherence to a healthy lifestyle and multiple sclerosis: a case-control study from the UK Biobank

BACKGROUND

Multiple sclerosis (MS) is a common and disabling condition. The importance of healthy lifestyle for this disease is poorly explored.

OBJECTIVE

To test whether adherence to healthier lifestyle patterns is associated with a lower presence of multiple sclerosis (MS).

METHODS

By using a case-control design, we investigated the combined association of four healthy lifestyle-related factors (no current smoking, healthy diet, exercising regularly, body mass index <30 kg/m²) and the prevalence of MS. A logistic regression analysis, adjusted for potential confounders, was used and data reported as odds ratios (ORs) with their 95% confidence intervals (CIs).

RESULTS

728 participants with MS were matched with healthy controls (n = 2,912) using a propensity score approach. In a multivariable analysis, compared to those who scored low in the composite lifestyle score (0-1 healthy lifestyle factors), people who adopted all four low risk lifestyle factors showed a 71% lower odds of having MS (OR = 0.29; 95% CI: 0.15-0.56). Moreover, there was a strong linear trend, suggesting that the higher number of healthy lifestyle behaviors was associated with lower odds of having MS.

CONCLUSION

Following a healthy lifestyle is associated with a lower prevalence of MS. This association should be explored further in cohort studies.