Mediterranean diet cools down the inflammatory milieu in type 2 diabetes: the MÉDITA randomized controlled trial

The effects of Mediterranean diet on cardiovascular risk factors, glycemic control and weight loss in patients with type 2 diabetes: a meta-analysis

To explore the impact of the Mediterranean diet on cardiovascular risk factors, glycemic control and weight loss in patients with type 2 diabetes(T2D) by a meta-analysis of randomized controlled trials (RCTs). We systematically searched PubMed, Cochrance Library, EMBASE and four Chinese databases to identify RCTs that compared the Mediterranean diet with control diets in patients with T2D up to December 2021. The Risk of Bias of the included studies was assessed using the version 2 of the Cochrane risk-of-bias tools for randomized trials (ROB 2). Seven RCTs with 1371 patients met the eligibility criteria and entered into the meta-analysis. Compared to control diets, the beneficial effects of Mediterranean diet were not statistically significant in high-density lipoprotein (MD = 2.33; 95% CI: -0.27 to 4.92), low-density lipoprotein (MD = -2.34; 95% CI -5.67 to 0.99) and total cholesterol (MD = 2.60; 95% CI: -0.95 to 6.15). But Mediterranean diet led to reduce the level of diastolic blood pressure (MD = -1.20; 95% CI: -2.21 to -0.19) and systolic blood pressure (MD = -4.17; 95% CI: -7.12 to -1.22). Meanwhile, Mediterranean diet showed beneficial effects in glycemic control (HbA1[%]: MD = -0.39, 95% CI: -0.58 to -0.20; fasting plasma glucose: MD = -15.12, 95% CI: -24.69 to -5.55) and weight loss (BMI: MD = -0.71, 95% CI: -1.30 to -0.78; WC: MD = -1.69; 95% CI: -3.35 to -0.02) compared to the control diets. The meta-analysis presented evidence supporting the beneficial effects of the Mediterranean diet on blood pressure, glycemic control, and weight loss. However, the impact of the Mediterranean diet on the lipid profile was not found to be significant, warranting further verification. This Meta-analysis was registered on the INPLASY website (Registration number: INPLASY 202160096).

Global comparison of the effect of non-pharmacological interventions on glycemic control in patients with type 2 diabetes: A network meta-analysis from 107 randomized controlled trials

OBJECTIVE

To investigate the effectiveness of non-pharmacological interventions (NPIs) on glycemic control in patients with type 2 diabetes (T2D) and to provide guidance for clinical healthcare-giver.

DESIGN

Network meta-analysis (NMA).

SETTING AND PARTICIPANTS

Randomized controlled trials comparing the effect of NPIs with usual care, waitlist, or other NPIs on glycemic control in patients with T2D.

METHODS

This NMA was guided by frequentist framework. PubMed, Embase, the Cochrane Library Central Register of Controlled Trials, Cumulated Index to Nursing and Allied Health Literature, and Web of Science were searched from their inception until January 2023. The primary outcome was HbA1c and secondary outcomes were cardiovascular risk scores and related psychosocial scores. Mean differences and standardized mean differences were pooled using NMA. Study quality was assessed with the Confidence in Network Meta-analysis.

RESULTS

A total of 107 studies (10,496 participants) were included. The median sample size of the included studies was 64 (range, 10-563) and the median duration was 3 months (range, 1-24). Compared to usual care, all NPIs except acupuncture (MD: -0.28; 95 % CI: -1.02, 0.26) and psychological therapy (MD: -0.29; 95 % CI: -0.66, 0.08) showed significantly differences in improving glycemic control in patients with T2D. And according to the results of surface under the cumulative ranking analysis and Cluster ranking, meditation therapy was considered to the best choice when balancing the efficacy of glycemic control with self-efficacy and diabetes related problems, while nutrition therapy was considered to the best choice when balancing quality of life with risk of cardiovascular complications.

CONCLUSIONS

These findings validate the efficacy of NPIs for glycemic control in patients with T2D and suggest that healthcare-giver should consider both the efficacy of interventions and the psychosocial needs of patients when developing NPIs programs.

The Effect of Dietary Patterns on Inflammatory Biomarkers in Adults with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Some evidence supports the fact that chronic low-grade inflammation contributes to the physiopathology of type 2 diabetes mellitus (T2DM), and circulating markers of inflammation (e.g., C-reactive protein (CRP), pro- and anti-inflammatory biomarkers (e.g., adiponectin), and endothelial function markers could indicate an ongoing pathology. Following certain dietary patterns (DPs) may result in favorable changes in inflammatory biomarkers. The overarching aim of this systematic review and meta-analysis is to explore the inflammatory effect of healthy DPs on inflammatory biomarkers in adults with T2DM. A systematic search of the literature was conducted using the electronic databases MEDLINE, SCOPUS, and Cochrane Central Register of Controlled Trials. A total of 10 randomized controlled clinical trials (RCTs) were analyzed. In our linear meta-analysis, the random-effects model was applied to estimate standardized mean differences (SMD) to associate the effect of the interventions. Dietary Approaches to Stop Hypertension (DASH), Diabetes UK healthy eating, Mediterranean Diet (MD), Diabetes Prevention Program (DPP), and the American Heart Association’s Therapeutic Lifestyle Changes diet were associated with a significant reduction in CRP (SMD: −0.83, 99% CI −1.49, −0.17, p < 0.001; I2 94%), while plasma levels of adiponectin were significantly higher with the intake of MD, DPP, and Diabetes UK healthy eating (SMD: 0.81, 99% CI 0.06,1.56, p < 0.005; I2 96%), both of which indicate less inflammation. Sensitivity analyses were carried out, and potential publication bias was examined. In conclusion, low- moderate-quality evidence from RCTs suggests that, for the DPs evaluated, there are favorable changes in CRP and adiponectin.

Pharmacological and non-pharmacological therapeutic interventions for the treatment of spinal cord injury-induced pain

Spinal cord injury (SCI) is a complex neurophysiological disorder, which can result in many long-term complications including changes in mobility, bowel and bladder function, cardiovascular function, and metabolism. In addition, most individuals with SCI experience some form of chronic pain, with one-third of these individuals rating their pain as severe and unrelenting. SCI-induced chronic pain is considered to be "high impact" and broadly affects a number of outcome measures, including daily activity, physical and cognitive function, mood, sleep, and overall quality of life. The majority of SCI pain patients suffer from pain that emanates from regions located below the level of injury. This pain is often rated as the most severe and the underlying mechanisms involve injury-induced plasticity along the entire neuraxis and within the peripheral nervous system. Unfortunately, current therapies for SCI-induced chronic pain lack universal efficacy. Pharmacological treatments, such as opioids, anticonvulsants, and antidepressants, have been shown to have limited success in promoting pain relief. In addition, these treatments are accompanied by many adverse events and safety issues that compound existing functional deficits in the spinally injured, such as gastrointestinal motility and respiration. Non-pharmacological treatments are safer alternatives that can be specifically tailored to the individual and used in tandem with pharmacological therapies if needed. This review describes existing non-pharmacological therapies that have been used to treat SCI-induced pain in both preclinical models and clinical populations. These include physical (i.e., exercise, acupuncture, and hyper- or hypothermia treatments), psychological (i.e., meditation and cognitive behavioral therapy), and dietary interventions (i.e., ketogenic and anti-inflammatory diet). Findings on the effectiveness of these interventions in reducing SCI-induced pain and improving quality of life are discussed. Overall, although studies suggest non-pharmacological treatments could be beneficial in reducing SCI-induced chronic pain, further research is needed. Additionally, because chronic pain, including SCI pain, is complex and has both emotional and physiological components, treatment should be multidisciplinary in nature and ideally tailored specifically to the patient.

Association of a pro-inflammatory diet with type 2 diabetes and hypertension: results from the Ravansar non-communicable diseases cohort study

BACKGROUND

Most non-communicable diseases (NCDs) are associated to diet and inflammation. The Dietary Inflammatory Index (DII) is a developed and validated self-assessment tool. The study was conducted to assess the association of DII with the hypertension (HTN) and type 2 diabetes mellitus (T2DM).

METHODS

This cross-sectional analysis was conducted on 9811 participants aged 35 to 65 years from the Ravansar Non-Communicable Diseases (RaNCD) cohort study's baseline phase data. The DII was calculated using 31 food frequency questionnaire parameters (FFQ). Univariable and multiple logistic regression was used to derive the estimates.

RESULTS

In healthy participants, the mean DII score was - 2.32 ± 1.60; in participants with T2DM, HTN, or T2DM&HTN, the mean DII score was - 2.23 ± 1.59, - 2.45 ± 1.60 and - 2.25 ± 1.60, respectively (P = 0.011). Males had a significantly higher pro-inflammatory diet than females (P <  0.001). BMI (body mass index), triglyceride, energy intake, smokers were significantly higher and socio-economic status (SES), physical activity and HDL-C were significantly lower in the most pro-inflammatory diet compared to the most anti-inflammatory diet. Participants with T2DM, HTN, and T2DM&HTN had significantly higher mean anthropometry indices (P <  0.001) and lipid profiles than healthy subjects (P <  0.001). After adjusting for age, gender, and physical activity, the probability of developing T2DM was 1.48 (95% CI: 1.19, 1.85) times greater in the fourth quartile of DII than in the first quartile.

CONCLUSIONS

The findings of this study showed that an anti-inflammatory diet are associated with HTN, T2DM, and the risk factors associated with these conditions. Modification of diet is recommended to reduce inflammation.

The Impact of Diet on Bone and Fracture Risk in Diabetes

PURPOSE OF REVIEW

The purpose of this review is to summarize the recently published scientific evidence on the effects of diet on diabetes and skeletal health.

RECENT FINDINGS

The impact of diet on overall health has been a growing topic of interest among researchers. An inappropriate eating habit is a relatively modified risk factor for diabetes in adults. Parallel with the significant increase in the incidence of diabetes mellitus worldwide, many studies have shown the benefits of lifestyle modifications, including diet and exercise for people with, or at risk of developing, diabetes. In the last years, accumulating evidence suggests that diabetes is a risk factor for bone fragility. As lifestyle intervention represents an effective option for diabetes management and treatment, there is potential for an effect on bone health. Healthy lifestyle is critical to prevent bone fragility. However, more studies are needed to fully understand the impact of diet and weight loss on fracture risk in diabetics.

Mediterranean dietary pattern and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of prospective cohort studies

PURPOSE

Previous meta-analyses assessed the association of adherence to the Mediterranean dietary pattern (MedDiet) with the risk of type 2 diabetes (T2D). Since then, new large-scale cohort studies have been published. In addition, dose-response relation was not previously investigated and the certainty of evidence was not assessed. We aimed to explore the dose-response relationship between adherence to the MedDiet and the risk of T2D.

METHODS

We did a systematic search using PubMed, Scopus, and ISI Web of Science upto April 2021 for prospective cohort studies of the relationship between adherence to the MedDiet and the risk of T2D in the general population. The summary relative risks (RR) and 95%CI were estimated by applying a random-effects model.

RESULTS

Fourteen prospective cohort studies (410,303 participants and 41,466 cases) were included. There was an inverse association for the highest versus lowest category of adherence to the MedDiet (RR: 0.79, 95%CI 0.72, 0.88; I² = 82%, n = 14; Risk difference:  - 21 per 1000 person, 95%CI  - 28,  - 12; GRADE = moderate certainty), and for a 2-point increment in the MedDiet adherence score (RR: 0.86, 95%CI 0.82, 0.91; n = 13). The RR remained significant after controlling for important confounders and in almost all subgroups, especially subgroups defined by geographical region. We observed an inverse linear association between MedDiet adherence score and T2D incidence.

CONCLUSION

Adherence to the MedDiet was inversely related to T2D risk in a dose-response manner. Adherence to a Mediterranean-style diet may be a good advice for the primary prevention of T2D.

REGISTRY AND REGISTRY NUMBER

PROSPERO (CRD42021246589).

Impact of the Mediterranean Dietary pattern on n-3 fatty acid tissue levels-A systematic review

INTRODUCTION

The Mediterranean Diet (MedDiet) is described as a plant-based dietary pattern with adherence associated with reductions in chronic disease risk and longevity. Although the nutrient profile is diverse and complex, the MedDiet is often described as a rich source of n-3 polyunsaturated fatty acids (PUFA) derived from fish, seafood and nuts. However, whether MedDiet adherence results in appreciable increases in tissue levels of n-3 PUFAs is yet to be systematically investigated. This systematic review synthesized the literature to determine the impact of the MedDiet on n-3 PUFA tissue levels.

MATERIALS AND METHODS

Medline, Embase, Amed, and CINAHL databases were searched for studies reporting on adherence to a MedDiet and tissue levels of n-3 PUFAs. PROSPERO registration number is CRD 42020162114.

RESULTS

Twenty-two studies were included. Seven were observational studies and 15 were randomised controlled trials (RCTs). All observational studies reported a positive relationship between adherence and higher tissue n-3 PUFA levels. Two-thirds (10/15) of RCTs reported significant increases in n-3 PUFA concentrations.

DISCUSSION

MedDiet adherence is associated with higher tissue levels of n-3 PUFA. However, we report heterogeneity in the description across all MedDiet interventions.

The mediterranean diet: Healthy and sustainable dietary pattern in the time of Sars-Cov-2

COVID-19, first reported in Wuhan, China in December 2019 quickly spread worldwide leading to serious health, social and economic consequences. A crucial role in the pathogenesis of severe disease has been attributed to the inflammatory status, that in more severe cases may evolve in an overproduction of pro-inflammatory cytokines (“cytokine storm)” and fatal outcome. Non-communicable diseases, nutritional disorders and advanced age, conditions associated with a low-grade systemic inflammation and immune function alterations, have been identified as major risks for severe COVID-19. General recommendations for fighting COVID-19 highlighted the paramount importance of adopting a healthy plant-based dietary pattern and healthy lifestyle. The Mediterranean dietary pattern is considered as one of the healthiest dietary patterns, and its benefits are supported by a large body of evidence. Furthermore, it is considered as a sustainable lifestyle model. The aim of this research was to update the multiple benefits of the Mediterranean dietary pattern on physical and mental health, focusing on the effects that it may have in combating COVID-19. The potential effects and mechanisms of action of the main bioactive components of Mediterranean diet were also analyzed. Considering its effects in modulating inflammation and oxidative stress and supporting the immune system, the Mediterranean dietary pattern may be considered the most promising dietary approach to combat COVID-19.

Effects of Dietary Patterns on Biomarkers of Inflammation and Immune Responses: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Altered immune cell phenotype and chronic inflammation are key features shared by various chronic diseases. Evidence from nutritional interventions aimed at alleviating inflammation could be a promising approach for the prevention of adverse health outcomes. We therefore aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to summarize the recent evidence on the effects of dietary patterns on inflammatory and immune-related biomarkers in humans. PubMed, Medline, and Web of Science databases were searched for publications up to October 2020. In total, 22 RCTs were included in the meta-analysis conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Mediterranean diet appeared as the dietary pattern that showed the most prominent reductions of inflammatory biomarkers such as IL-6 [mean difference (MD): -1.07 pg/mL (95% CI: -1.94, -0.20); I2: 96%], IL-1β [MD: -0.46 pg/mL (95% CI: -0.66, -0.25); I2: 0%], and C-reactive protein [MD: -1.00 mg/L (95% CI: -2.02, 0.01); I2: 100%]. No substantial effects were observed for the additional dietary patterns studied in intervention research, including the Dietary Adherence to Stop Hypertension diet, and the vegetarian or vegan diets. Future large-scale multifactorial intervention studies are warranted to allow direct comparison of various dietary patterns in relation to a range of biomarkers reflecting multiple inflammatory and immune-related pathways.

Poor quality of dietary assessment in randomized controlled trials of nutritional interventions for type 2 diabetes may affect outcome conclusions: A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to evaluate the quality of dietary assessment methods in randomized controlled trials focusing on individuals with type 2 diabetes (T2DM), and its impact on the favorability of conclusions.

METHODS

MEDLINE, EMBASE, CINAHL, and CENTRAL were searched, from inception until September 2019 for RCTs of dietary interventions in individuals with T2DM. Investigators assessed risk of bias and quality of the dietary measurements using the Cochrane Risk of Bias Assessment Tool 2.0 and the redeveloped EURICA tool, respectively. Random-effects meta-analysis assessed mean changes in hemoglobin (Hb)A1c. The study was conducted in accordance with the Preferred Reporting in Systematic Reviews and Meta-analyses. PROSPERO registration number: CRD42019146471.

RESULTS

Of 2552 records retrieved, 23 studies met the inclusion criteria. Two studies were rated as good, 6 as medium, and 15 as poor in the quality assessment of the dietary measurement tool. All eight studies with higher quality of dietary assessment were associated with favorable conclusions. Among the 15 studies with poor quality, 5 failed to draw favorable conclusions. Among studies that sought to produce a reduction in HbA1c, 3 of 6 with better dietary assessment quality produced a significant difference of -0.38% (-0.67% to -0.08%), and 4 of 12 of poorer quality produced a significant difference of -0.26% (-0.37% to -0.14%).

CONCLUSIONS

The poor quality of dietary assessment in clinical trials casts uncertainty on the dietary outcomes and the validity of possible causal mechanisms. Attention to the accuracy and reliability of dietary assessment methods is indicated.

The Mediterranean diet and health: a comprehensive overview

The Mediterranean diet (MedDiet), one of the most studied and well-known dietary patterns worldwide, has been associated with a wide range of benefits for health. In the present narrative review, we aimed to provide a comprehensive overview of the current knowledge on the relation of the MedDiet to important health outcomes, considering both observational and intervention studies with both risk factors and clinical diseases as outcomes. In addition, we considered the clinical and public health impacts of the MedDiet on both human and planetary health. Earlier research confirmed by recent studies has provided strong evidence for the benefits of the MedDiet on cardiovascular health, including reduction in the incidence of cardiovascular outcomes as well as risk factors including obesity, hypertension, metabolic syndrome, and dyslipidaemia. There is also evidence that MedDiet is associated with lower rates of incident diabetes, and better glycaemic control in diabetic patients compared to control diets. In prospective studies, adherence to the MedDiet reduced mortality, especially cardiovascular mortality, hence increased longevity. In addition, it has been associated with less age-related cognitive dysfunction and lower incidence of neurodegenerative disorders, particularly Alzheimer's disease. Furthermore, the relatively low environmental impacts (water, nitrogen and carbon footprint) of the MedDiet is an additional positive aspect of the Mediterranean dietary model. It is likely that the combination of a healthy diet with social behaviours and the way of life of Mediterranean regions makes the MedDiet a sustainable lifestyle model that could likely be followed in other regions with country-specific and culturally appropriate variations.

Efficacy of Dietary and Supplementation Interventions for Individuals with Type 2 Diabetes

The prevalence of Type 2 diabetes (T2D) is increasing, which creates a large economic burden. Diet is a critical factor in the treatment and management of T2D; however, there are a large number of dietary approaches and a general lack of consensus regarding the efficacy of each. Therefore, the purpose of this narrative review is twofold: (1) to critically evaluate the effects of various dietary strategies on diabetes management and treatment, such as Mediterranean diet, plant-based diet, low-calorie and very low-calorie diets, intermittent fasting, low-carbohydrate and very low-carbohydrate diets, and low glycemic diets and (2) to examine several purported supplements, such as protein, branched-chain amino acids, creatine, and vitamin D to improve glucose control and body composition. This review can serve as a resource for those wanting to evaluate the evidence supporting the various dietary strategies and supplements that may help manage T2D.

What Can We Change in Diet and Behaviour in Order to Decrease Carotid Intima-Media Thickness in Patients with Obesity?

Atherosclerosis—considered the major cause of cardiovascular diseases (CVDs)—is strongly associated with obesity, to which it strongly contributes. Moreover, atherosclerosis is characterised by a long asymptomatic phase, and its progression can lead to serious cardiovascular (CV) events. The carotid intima-media thickness (cIMT) has been determined as a predictor of CV events, as well as a marker of subclinical atherosclerosis, and has been used in clinical trials as an alternative assessment method or a surrogate endpoint. It should be noted that several behavioural approaches can directly influence the cIMT values, and decrease or increase the CV risk. In our paper, we aimed to summarize the current knowledge regarding IMT measurement among patients with obesity as a risk group—also in terms of the obesity paradox where the diagnosis of subclinical atherosclerosis is especially essential and implements the early therapeutic approach. We also summarized behavioural, modifiable factors, such as the Mediterranean diet, the Dietary Approach to Stop Hypertension Diets, body weight reduction or the intake of micro- and macronutrients, with a particular focus on the studies where the cIMT values were one of the outcomes. In order to collect the literature data related to the presented topic, the PubMed database was explored.

The Influence of Nutrition on Adiponectin-A Narrative Review

The adipose tissue is an active endocrine organ which synthesizes and secretes a variety of adipokines, including adiponectin with its anti-inflammatory properties. Its expression is influenced by numerous factors such as age, sex, body weight and adipose tissue content. However, dietary factors, i.e., diet structure and the percentage of individual nutrients and products, are very important modulators. Beneficial dietary habits are the Mediterranean diet, DASH diet, diet based on plant products and diet with reduced energy value. Moreover, the share of individual products and nutrients which increase the concentration of adiponectin is worth noting. This group may include monounsaturated fatty acids, polyunsaturated omega-3 fatty acids, dietary fiber, polyphenols, alcohol and milk products. Conversely, dietary ingredients which have a negative effect on the concentration of adiponectin are typical components of the Western diet: saturated fatty acids, trans fatty acids, monosaccharides and disaccharides, and red meat. Furthermore, a diet characterized by a high glycemic index such as a high-carbohydrate low-fat diet also seems to be unfavorable. Due to the fact that available knowledge should be systematized, this study aimed to summarize the most recent research on the influence of dietary factors on the concentration of adiponectin.

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.

Analysis of the intricate effects of polyunsaturated fatty acids and polyphenols on inflammatory pathways in health and disease

Prevention and treatment of non-communicable diseases (NCDs), including cardiovascular disease, diabetes, obesity, cancer, Alzheimer's and Parkinson's disease, arthritis, non-alcoholic fatty liver disease and various infectious diseases; lately most notably COVID-19 have been in the front line of research worldwide. Although targeting different organs, these pathologies have common biochemical impairments - redox disparity and, prominently, dysregulation of the inflammatory pathways. Research data have shown that diet components like polyphenols, poly-unsaturated fatty acids (PUFAs), fibres as well as lifestyle (fasting, physical exercise) are important factors influencing signalling pathways with a significant potential to improve metabolic homeostasis and immune cells' functions. In the present manuscript we have reviewed scientific data from recent publications regarding the beneficial cellular and molecular effects induced by dietary plant products, mainly polyphenolic compounds and PUFAs, and summarize the clinical outcomes expected from these types of interventions, in a search for effective long-term approaches to improve the immune system response.

Mediterranean Diet Effects on Type 2 Diabetes Prevention, Disease Progression, and Related Mechanisms. A Review

The search for a quality diet has grown over the past decade. Diet is considered one of the pillars for the prevention and progression of several diseases, among them: diabetes. Type 2 diabetes (T2D) is an epidemic of western countries that increases the vulnerability of other diseases, such as cardiovascular and cancer. T2D is associated with lifestyle and diet. The traditional Mediterranean diet has proven its benefits over several cardiovascular risk factors, and specifically on diabetes. This review compiles recent published evidence on the effects of the Mediterranean diet on the incidence and progression of type 2 diabetes (T2D) and its relation with several other cardiovascular healthy diets. We will also focus on how the Mediterranean diet could play a role in T2D-related mechanisms, such as anti-inflammatory or antioxidant compounds, glucagon-like peptide agonist compounds, and changes in gut microbiota. Each component of the Mediterranean diet could be involved in processes related to diabetes homeostasis, many of them sharing common physio-pathological pathways. The importance of this diet within the set of habits of a healthy lifestyle must be emphasized.

Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota

The interaction between nutrition and the immune system is very complex. In particular, at every stage of the immune response, specific micronutrients, including vitamins and minerals play a key role and often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual's overall nutrition status and pattern of dietary intake (comprised of nutrients and non-nutritive bioactive compounds and food) and any supplementation with nutraceuticals including vitamins and minerals, can influence positively or negatively the function of the immune system. This influence can occur at various levels from the innate immune system and adaptive immune system to the microbiome. Although there are conflicting evidence, the current results point out that dietary supplementation with some nutrients such as vitamin D and zinc may modulate immune function. An update on the complex relationship between nutrition, diet, and the immune system through gut microbiota is the aim of this current review. Indeed, we will provide the overview of the link among immune function, nutrition and gut microbiota, paying particular attention at the effect of the Mediterranean diet on the immune system, and finally we will speculate the possible role of the main one functional supplements on immune function.

A proinflammatory diet is associated with inflammatory gene expression among healthy, non-obese adults: Can social ties protect against the risks?

The Western diet, characterized by high intake of saturated fat, sugar, and salt, is associated with elevated inflammation and chronic disease risk. Few studies have investigated molecular mechanisms linking diet and inflammation; however, a small number of randomized controlled trials suggest that consuming an anti-inflammatory diet (i.e., a primarily plant-based diet rich in monounsaturated fat and lean protein) decreases proinflammatory gene expression. The current study investigated the association between everyday diet and proinflammatory gene expression, as well as the extent to which central adiposity and social involvement modulate risk. Participants were healthy middle-aged and older adults (N = 105) who completed a food frequency questionnaire and reported how many close social roles they have. Anthropometric measurements and blood samples also were collected; gene expression data were analyzed from LPS-stimulated peripheral blood mononuclear cells for interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α. The inflammatory potential of each participant's diet was calculated using the Dietary Inflammatory Index (DII®). Participants with higher DII® scores, indicating a more proinflammatory diet, had greater IL-6 (b = -0.02, SE = 0.008, p = .01), IL-1β (b = -0.01, SE = 0.006, p = .03), and TNF-α (b = -0.01, SE = 0.005, p = .04) gene expression if they had a smaller sagittal abdominal diameter (SAD); effects were not seen among those with higher SADs. Social involvement served a protective role, such that participants with smaller SADs had greater IL-6 (b = 0.01, SE = 0.004, p = .049) and IL-1β (b = 0.01, SE = 0.003, p = .045) gene expression only if they had less social involvement; there was no effect of diet on gene expression among those who reported greater social participation. Results are the first to demonstrate a link between self-reported diet and proinflammatory gene expression. Importantly, the effect of diet on gene expression depended upon both body fat composition and social participation, both of which have previously been linked directly with proinflammatory gene expression and inflammation.

Benefits of the Mediterranean diet: Epidemiological and molecular aspects

More than 50 years after the Seven Countries Study, a large number of epidemiological studies have explored the relationship between the Mediterranean diet (MD) and health, through observational, case-control, some longitudinal and a few experimental studies. The overall results show strong evidence suggesting a protective effect of the MD mainly on the risk of cardiovascular disease (CVD) and certain types of cancer. The beneficial effects have been attributed to the types of food consumed, total dietary pattern, components in the food, cooking techniques, eating behaviors and lifestyle behaviors, among others. The aim of this article is to review and summarize the knowledge derived from the literature focusing on the benefits of the MD on health, including those that have been extensively investigated (CVD, cancer) along with more recent issues such as mental health, immunity, quality of life, etc. The review begins with a brief description of the MD and its components. Then we present a review of studies evaluating metabolic biomarkers and genotypes in relation to the MD. Other sections are dedicated to observation and intervention studies for various pathologies. Finally, some insights into the relationship between the MD and sustainability are explored. In conclusion, the research undertaken on metabolomics approaches has identified potential markers for certain MD components and patterns, but more investigation is needed to obtain valid measures. Further evaluation of gene-MD interactions are also required to better understand the mechanisms by which the MD diet exerts its beneficial effects on health. Observation and intervention studies, particularly PREDIMED, have provided invaluable data on the benefits of the MD for a wide range of chronic diseases. However further research is needed to explore the effects of other lifestyle components associated with Mediterranean populations, its environmental impact, as well as the MD extrapolation to non-Mediterranean contexts.

Dietary patterns and management of type 2 diabetes: A systematic review of randomised clinical trials

BACKGROUND AND AIM

The aim of the present review is to examine evidence from published studies on the effectiveness of six or more months of low carbohydrate, macrobiotic, vegan, vegetarian, Mediterranean and intermittent fasting (IF) diets compared to low fat diets on diabetes control and management.

METHODS AND RESULTS

In accordance with PRISMA guidelines, Cochrane CENTRAL, PubMed and Scopus databases were systematically searched for relevant studies. Twenty randomised controlled trials (RCTs) > 6 months that investigated the effectiveness of various dietary patterns on type 2 diabetes mellitus (T2DM) were included. Risk of bias was assessed using the Cochrane tool. There were no significant differences in glycemic control, weight and lipids for the majority of low carbohydrate diets (LCDs) compared to low fat diets (LFDs). Four out of fifteen LCD interventions showed better glycemic control while weight loss was greater in one study. The Mediterranean dietary pattern demonstrated greater reduction in body weight and HbA1c levels and delayed requirement for diabetes medications. The vegan and macrobiotic diet demonstrated improved glycemic control, while the vegetarian diet showed greater body weight reduction and insulin sensitivity.

CONCLUSIONS

Although more long-term intervention trials are required, mounting evidence supports the view that vegan, vegetarian and Mediterranean dietary patterns should be implemented in public health strategies, in order to better control glycemic markers in individuals with T2DM.

What is the effect of a Mediterranean compared with a Fast Food meal on the exercise induced adipokine changes? A randomized cross-over clinical trial

Background

Adipose tissue-derived adipokines are pro-inflammatory cytokines involved in metabolic-related diseases and can be influenced by diet and exercise. We aimed to compare the effect of a Mediterranean (MdM) compared with Fast Food (FFM) meal on the exercise induced adipokines changes.

Methods

In a double blinded cross over trial, 46 participants were randomly assigned to one of two standardized iso-energy pre-exercise meals: FFM or MdM-type. Three hours after each meal, participants completed a treadmill exercise test (EC). Serum adiponectin, resistin, PAI-1, lipocalin-2/NGAL and adipsin were determined by Luminex magnetic bead immunoassay. Wilcoxon signed rank test compared changes before/after meal and before/after EC and a linear mixed model evaluated the effect of meals on the adipokine response to exercise, adjusted for confounders.

Results

Thirty-nine participants (mean age of 25, with a standard deviation of 5 years) completed the trial (56% females). For both interventions, a significant reduction of adipsin after each meal and a significant increase of lipocalin, PAI-1, adipsin and resistin, after exercise was observed. When exercise was preceded by a MdM meal a higher increase in adipsin levels was seen.

Conclusion

Acute exercise induced an increase of circulatory levels of adipsin, resistin, lipocalin and PAI-1, but not adiponectin. A pre-exercise Mediterranean meal potentiated the increase of adipsin after the exercise test, which possibly relates to the immune regulatory role of adipsin. These changes suggest a cross-talk between the immune and metabolic immediate response to exercise and its modulation by the pre-exercise diet composition.

Change in Plant-Based Diet Quality Is Associated with Changes in Plasma Adiposity-Associated Biomarker Concentrations in Women

BACKGROUND

A healthful plant-based diet is associated with lower risk of cardiometabolic diseases. However, it is still unclear whether such benefits are due to its favorable effects on adiposity-associated biomarkers.

OBJECTIVE

We investigated the associations between biomarkers and 3 plant-based diet indices: an overall plant-based diet index (PDI); a healthful plant-based diet index (hPDI); and an unhealthful plant-based diet index (uPDI).

METHODS

In the Nurses' Health Study II, 831 women [baseline mean age: 45 y; body mass index (BMI, kg/m2): 24.6] were randomly selected from those who provided 2 blood samples in 1996-1999 and 2010-2011 to measure plasma concentrations of adiponectin, leptin, soluble leptin receptor (sOB-R), insulin, retinol-binding protein-4, high-sensitivity C-reactive protein (hsCRP), and interleukin-6 (IL-6). Plant-based diet indices were derived from semiquantitative food frequency questionnaires assessed at each blood collection. Linear mixed models were used to evaluate cross-sectional associations, and general linear models were used to evaluate longitudinal associations.

RESULTS

In cross-sectional analyses with multivariable adjustment including BMI, higher hPDI was associated with lower concentrations of leptin, insulin, and hsCRP, and higher adiponectin and sOB-R concentrations (biomarker differences per 10-point higher hPDI: -7.2%, -10.0%, -13.6%, 3.0%, and 1.9%, respectively; P ≤ 0.025). A higher uPDI was associated with higher concentrations of leptin and insulin (4.4% and 4.8%, respectively; P ≤ 0.048). In longitudinal analyses with multivariable adjustment including weight change, an increase in hPDI (improved plant-based diet quality) was inversely associated with changes in leptin and hsCRP (biomarker changes per 10-point hPDI increase: -7.7% and -17.8%, respectively; P ≤ 0.005), whereas an increase in uPDI (worsened plant-based diet quality) was positively associated with changes in leptin, hsCRP, and IL-6 (10.1%, 13.5%, and 12.4%, respectively; P ≤ 0.021).

CONCLUSIONS

Adherence to a healthful plant-based diet is associated with favorable long-term changes in adiposity-associated biomarker concentrations in women.

The impact of major dietary patterns on glycemic control, cardiovascular risk factors, and weight loss in patients with type 2 diabetes: A network meta-analysis

OBJECTIVE

To comprehensively compare the differences between major dietary patterns in improving glycemic control, cardiovascular risk, and weight loss for patients with type 2 diabetes.

METHOD

We systematically searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) to identify randomized controlled trials (RCTs) that compared the efficacy of Mediterranean, low-carbohydrate, and/or low-fat dietary patterns for patients with type 2 diabetes. Studies that compared any one of those diets with regular diet were also included. The risk of bias in eligible RCTs was evaluated according to the Cochrane Handbook. The primary outcome was glycemic control. Secondary outcomes included weight loss and cardiovascular risk factors. A network meta-analysis was performed using R-3.3.2.

RESULTS

Ten RCTs involving five dietary patterns met the eligibility criteria. The findings revealed that compared to low-fat diet, Mediterranean diet showed beneficial effects in glycemic control (HbA1c [%]: MD = -0.45, 95% CI = -0.55 to -0.34; fasting plasma glucose [mmol/L]: MD = -1.24 95% CI = -1.57 to -0.91, respectively; weight loss [kg]: MD =-1.18, 95% CI = -1.99 to -0.37; waist circumference [cm]: MD = -0.73, 95% CI = -1.26 to -0.19), and cardiovascular risk factors (HDL-cholesterol [mmol/L]: MD = 0.07, 95% CI = 0.04 to 0.11; total cholesterol [mmol/L]: MD = -0.17, 95% CI = -0.26 to -0.08; triglycerides [mmol/L]: MD = -0.21, 95% CI = -0.27 to -0.16). Network meta-analysis showed that high-carbohydrate diet improved HDL-cholesterol (mmol/l) (MD = 1.04, 95% CI = 0.39 to 1.68) when compared with regular diet. The differences were not statistically significant in other indirect comparison groups for other outcomes.

CONCLUSIONS

A mediterranean diet showed beneficial improvements in glycemic control, weight loss, and cardiovascular risk factors in people with type 2 diabetes.

Dietary Fatty Acids and the Metabolic Syndrome: A Personalized Nutrition Approach

Dietary fatty acids are present in a wide variety of foods and appear in different forms and lengths. The different fatty acids are known to have various effects on metabolic health. The metabolic syndrome (MetS) is a constellation of risk factors of chronic diseases. The etiology of the MetS is represented by a complex interplay of genetic and environmental factors. Dietary fatty acids can be important contributors of the evolution or in prevention of the MetS; however, great interindividual variability exists in the response to fatty acids. The identification of genetic variants interacting with fatty acids might explain this heterogeneity in metabolic responses. This chapter reviews the mechanisms underlying the interactions between the different components of the MetS, dietary fatty acids and genes. Challenges surrounding the implementation of personalized nutrition are also covered.

From inflammation to sexual dysfunctions: a journey through diabetes, obesity, and metabolic syndrome

Metabolic diseases are associated with chronic low-grade inflammation, which has been indicated as a potential mediator of endothelial dysfunction and cardiovascular disease. Visceral adiposity is thought to be the starting condition of the inflammatory state through the release of inflammatory cytokines, including TNF-alpha, CRP, and IL-6, which in turn promote endothelial dysfunction, endothelial expression of chemokines (IL-1) and adhesion molecules (ICAM-1, VCAM-1, and P-selectin), and the inhibition of anti-atherogenic factors (adiponectin). Obesity, metabolic diseases, and diabetes, all conditions characterized by abdominal fat, are well-recognized risk factors for sexual dysfunction in both sexes. Evidence from randomized-controlled trials supports the association between inflammatory milieau and erectile dysfunction in men suffering from metabolic diseases, whereas, in women, this has to be confirmed in further studies. A healthy lifestyle based on dietary pattern with high content of whole grain, fruit, nuts and seeds, and vegetables and low in sodium and saturated fatty acids plus regular physical activity may help to modulate the pro-inflammatory state associated with metabolic diseases and the related burden of sexual dysfunctions.

More sugar? No, thank you! The elusive nature of low carbohydrate diets

In the past decades, dietary guidelines focused on reducing saturated fat as the primary strategy for cardiovascular disease prevention, neglecting the many other potential effects of diet on health, in particular the harmful effects of sugar. A greater intake of soft drinks (sugar-sweetened beverages), for example, is associated with a 44% increased prevalence of metabolic syndrome, a higher risk of obesity, and a 26% increased risk of developing diabetes mellitus. Carbohydrates comprise around 55% of the typical western diet, ranging from 200 to 350 g/day in relation to a person's overall caloric intake. For long-term weight gain, food rich in refined grains, starches, and sugar appear to be major culprits. Low-carbohydrate diets restrict daily carbohydrates between 20 and 50 g, as in clinical ketogenic diets. The results of controlled trials show that people on ketogenic diets (a diet with no more than 50 g carbohydrates/day) tend to lose more weight than people on low-fat diets. Moreover, there is no good evidence for recommending low-fat diets, as low-carbohydrate diets lead to significantly greater weight loss (1.15 kg) than did low-fat interventions. However, the magnitude of such a benefit is small. As the quality of ingested carbohydrates seems more important than the quantity for health outcomes, people with metabolic disorders should avoid or substantially reduce low-fiber, rapidly digested, refined grains, starches, and added sugars. So, the consumption of the right carbohydrates (high-fiber, slowly digested, and whole grains), in a moderately lower amount (between 40 and 50% of daily energy content), is compatible with a state of good health and may represent a scientifically-based and palatable choice for people with metabolic disorders.

Differences in the interpretation of a modernized Mediterranean diet prescribed in intervention studies for the management of type 2 diabetes: how closely does this align with a traditional Mediterranean diet?

PURPOSE AND METHODS

Adherence to Mediterranean diet (MedDiet) is associated with the prevention and management of type 2 diabetes mellitus (T2DM). However, in intervention studies, there is discordance in the interpretation of a MedDiet. The purpose of this paper was to examine, synthesize, and develop a narrative review, exploring the qualitative differences in the interpretation of a modernized MedDiet prescribed as an intervention in clinical trials for the management of T2DM, and how closely this aligns with a traditional MedDiet. The 'traditional' MedDiet is often described as a dietary pattern high in unprocessed plant foods (fruits, vegetables, legumes, nuts, wholegrain cereals, and olive oil); moderate consumption of wine; low moderate in fish/shellfish; and an infrequent consumption of red meat, animal fats, vegetable oils, and processed foods.

RESULTS AND CONCLUSIONS

Synthesis of the reviewed literature demonstrates considerable variation in the qualitative interpretation of a MedDiet. We also identified inadequate reporting of MedDiet interventions, despite a number of studies referring to their intervention as a 'traditional' MedDiet. The majority of studies emphasized the same key dietary components and principles: an increased intake of vegetables, wholegrains, and the preferential consumption of white meat in substitute of red and processed meat and abundant use of olive oil. However, the reporting of specific dietary recommendations for fruit, legumes, nuts, bread, red wine, and fermentable dairy products were less consistent or not reported. Irrespective of the discordance in the interpretation of a MedDiet, a number of studies included in the present review reported improved glycaemic control and favorable cardiovascular outcomes with adherence to a Mediterranean-style diet. Nevertheless, greater clarity and depth of reporting amongst intervention studies is warranted for the refinement of a modernized MedDiet definition that is distinct from a prudent dietary pattern.

Evaluation of Mediterranean diet adherence scores: a systematic review

OBJECTIVE

The aim of this review was to evaluate the conceptual suitability, applicability and psychometric properties of scores used internationally to measure adherence to the Mediterranean diet (MD).

DESIGN

This was a systematic review to identify original articles that examined some aspects of the conceptual suitability, applicability or psychometric properties of the MD adherence score. Electronic searches were carried out on the international databases MEDLINE, Scopus, Web of Science and EMBASE (from January 1980 to 31 December 2015).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

The study included original articles that examined some aspects of the conceptual suitability, applicability or psychometric properties of the MD adherence score. The studies where MD adherence scores were administered but did not bring forward any evidence about their performance related to conceptual suitability, applicability or psychometric properties were excluded.

DATA EXTRACTION

Information relating to the scales was extracted in accordance with the quality criteria defined by the Scientific Advisory Committee of the Medical Outcomes Trust for measurement of health results and the quality criteria recommended by Terwee: (1) conceptual, (2) applicability and (3) psychometric properties. Three authors independently extracted information from eligible studies.

RESULTS

Twenty-seven studies were identified as meeting the inclusion criteria, yielding 28 MD adherence scores. The results showed that evidence is scarce and that very few scores fulfilled the applicability parameters and psychometric quality. The scores developed by Panagiotakos et al, Buckland et al and Sotos-Prieto et al showed the highest levels of evidence.

CONCLUSIONS

Scores measuring adherence to MD are useful tools for identifying the dietary patterns of a given population. However, further information is required regarding existing scores. In addition, new instruments with greater conceptual and methodological rigour should be developed and evaluated for their psychometric properties.

Adherence to the Mediterranean Diet and Inflammatory Markers

The aim was to assess inflammatory markers among adults and adolescents in relation to the adherence to the Mediterranean diet. A random sample (219 males and 379 females) of the Balearic Islands population (12-65 years) was anthropometrically measured and provided a blood sample to determine biomarkers of inflammation. Dietary habits were assessed and the adherence to the Mediterranean dietary pattern calculated. The prevalence of metabolic syndrome increased with age in both sexes. The adherence to the Mediterranean diet in adolescent males was 51.3% and 45.7% in adults, whereas in females 53.1% and 44.3%, respectively. In males, higher adherence to the Mediterranean diet was associated with higher levels of adiponectin and lower levels of leptin, tumor necrosis factor alpha (TNF-α), plasminogen activator inhibitor 1 (PAI-1) and high-sensitivity C-reactive protein (hs-CRP) in adults, but not in young subjects. In females, higher adherence was associated with lower levels of leptin in the young group, PAI-1 in adults and hs-CRP in both groups. With increasing age in both sexes, metabolic syndrome increases, but the adherence to the Mediterranean diet decreases. Low adherence to the Mediterranean dietary pattern (MDP) is directly associated with a worse profile of plasmatic inflammation markers.

Mediterranean Diet attenuates risk of frailty and sarcopenia: New insights and future directions

Sarcopenia and physical frailty are associated with progressive disability and predictive of negative health outcomes. Dietary interventions are considered the cornerstone in the management of sarcopenic symptomology and physical frailty. However few studies have investigated preventative strategies. Moreover, most studies have focused on the efficacy of individual nutrients or supplements rather than dietary patterns. The Mediterranean Diet (MedDiet) is a dietary pattern that provides evidence for an association between diet quality, healthy ageing and disease prevention. The purpose of this paper was to examine, synthesise and develop a narrative review of the current literature, investigating the potential benefits associated with adherence to a MedDiet and attenuation of physical frailty and sarcopenic symptomology in older adults. We also explored the underlying mechanisms underpinning the potential benefits of the MedDiet on ameliorating physical frailty and sarcopenic symptomology. Synthesis of the reviewed literature is suggestive of a decreased risk of physical frailty and sarcopenic symptomology with greater adherence to a MedDiet. We identified the anti-inflammatory and high antioxidant components of the MedDiet as two potential biological mechanisms involved. Due to a lack of evidence from RCTs to support the proposed physiological mechanisms, we suggest investigating these observations in older adults with type 2 diabetes (T2DM) whom are vulnerable to physical frailty and disability. A number of biological mechanisms describing the pathway to disability in older adults with T2DM have been postulated with many of these mechanisms potentially mitigated with dietary interventions involving the MedDiet. Exploring these mechanisms with the use of well-designed, longer-term dietary intervention studies in older adults with an increased vulnerability to physical frailty and sarcopenia is warranted.  

Mediterranean-type diets and inflammatory markers in patients with coronary heart disease: a systematic review and meta-analysis

The health benefits of a Mediterranean diet are thought to be mediated via its anti-inflammatory effects; however, the anti-inflammatory effect of this diet is unclear in patients who have already developed coronary heart disease (CHD). This systematic review and meta-analysis assessed the effect of Mediterranean-type diets on cytokines and adipokines in patients with CHD. An electronic search of the literature was conducted up to October 2016 using PubMed, Scopus, Web of Science, and Cochrane Library. Eleven of the 435 articles identified met eligibility criteria. Four observational studies reported significant inverse associations between Mediterranean-type diet scores and inflammatory cytokines. Five clinical trials (4 in non-Mediterranean countries) demonstrated nonsignificant reductions, and 2 trials conducted in Spain demonstrated significant reductions in C-reactive protein with a Mediterranean-type diet. Random effects meta-analysis of 4 controlled trials detected a nonsignificant difference in final mean value of C-reactive protein with Mediterranean-type diet vs low-fat diet. Despite promising findings from observational studies, this review demonstrated mostly nonsignificant effects of Mediterranean-type diet interventions on inflammatory cytokines and no effect in comparison to low-fat diets in controlled trials conducted primarily in Mediterranean populations. Therefore, randomized controlled trials of a traditional Mediterranean diet in non-Mediterranean populations and with multiple inflammatory biomarkers are needed in the high-risk CHD patient group.

Mediterranean diet for type 2 diabetes: cardiometabolic benefits

Dietary patterns influence various cardiometabolic risk factors, including body weight, lipoprotein concentrations, and function, blood pressure, glucose-insulin homeostasis, oxidative stress, inflammation, and endothelial health. The Mediterranean diet can be described as a dietary pattern characterized by the high consumption of plant-based foods, olive oil as the main source of fat, low-to-moderate consumption of fish, dairy products and poultry, low consumption of red and processed meat, and low-to-moderate consumption of wine with meals. The American Diabetes Association and the American Heart Association recommend Mediterranean diet for improving glycemic control and cardiovascular risk factors in type 2 diabetes. Prospective studies show that higher adherence to the Mediterranean diet is associated with a 20-23 % reduced risk of developing type 2 diabetes, while the results of randomized controlled trials show that Mediterranean diet reduces glycosylated hemoglobin levels by 0.30-0.47 %, and is also associated with a 28-30 % reduced risk for cardiovascular events. The mechanisms by which Mediterranean diet produces its cardiometabolic benefits in type 2 diabetes are, for the most, anti-inflammatory and antioxidative: increased consumption of high-quality foods may cool down the activation of the innate immune system, by reducing the production of proinflammatory cytokines while increasing that of anti-inflammatory cytokines. This may favor the generation of an anti-inflammatory milieu, which in turn may improve insulin sensitivity in the peripheral tissues and endothelial function at the vascular level and ultimately act as a barrier to the metabolic syndrome, type 2 diabetes and development of atherosclerosis.

Effect of plant-based diets on obesity-related inflammatory profiles: a systematic review and meta-analysis of intervention trials

Plant-based dietary interventions have been proposed to reduce obesity induced chronic low-grade inflammation and hence prevent chronic disease risk; however, human evidence remains unclear. This systematic review and meta-analysis of intervention trials aimed to assess the effect of plant-based diets on obesity-related inflammatory biomarker profiles. Medline, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for articles published until January 2016 and mean differences in biomarkers of inflammatory status were assessed for: C-reactive protein (CRP), interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-ɑ), soluble intercellular adhesion molecule 1 (sICAM), leptin, adiponectin and resistin. Of initially identified 2,583 publications, 29 met the meta-analysis inclusion criteria [a total of 2,689 participants]. Consumption of plant-based diets was associated with a reduction in the mean concentrations of the following biomarkers: CRP [effect size, -0.55 mg/l, 95% confidence intervals (CI): -0.78; -0.32, I²  = 94.4%], IL-6 [effect size, -0.25 ng/l, 95% CI: -0.56; 0.06, I²  = 74%], and, to some degree, sICAM (-25.07 ng/ml [95% CI: -52.32; 2.17, I²  = 93.2%]). No substantial effects were revealed for TNF-ɑ, resistin, adiponectin and leptin. Plant-based diets are associated with an improvement in obesity-related inflammatory profiles and could provide means for therapy and prevention of chronic disease risk.