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Evaluating the effects of dietary patterns on circulating C-reactive protein levels in the general adult population: an umbrella review of meta-analyses of interventional and observational studies
Abstract
Adopting a healthy dietary pattern may be an initial step in combating inflammation-related chronic diseases; however, a comprehensive synthesis evaluating current evidence is lacking. This umbrella review aimed to summarise the current evidence on the effects of dietary patterns on circulating C-reactive protein (CRP) levels in adults. We conducted an exhaustive search of the Pubmed, Scopus and Epistemonikos databases, spanning from their inception to November 2023, to identify systematic reviews and meta-analyses across all study designs. Subsequently, we employed a random-effects model to recompute the pooled mean difference. Methodological quality was assessed using the A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2) checklist, and evidence certainty was categorised as non-significant, weak, suggestive, highly suggestive or convincing (PROSPERO: CRD42023484917). We included twenty-seven articles with thirty meta-analyses of seven dietary patterns, fifteen of which (50 %) exhibited high methodological quality. The summary effects of randomised controlled trials (RCT) found that the Mediterranean diet was the most effective in reducing circulating CRP levels, followed by Vegetarian/Vegan and Energy-restricted diets, though the evidence was of weak quality. In contrast, Intermittent Fasting, Ketogenic, Nordic and Paleolithic diets did not show an inverse correlation with circulating CRP levels. Some results from combined interventional and observational studies, as well as solely observational studies, also agreed with these findings. These dietary patterns show the potential in reducing CRP levels in adults, yet the lack of high-quality evidence suggests future studies may alter the summary estimates. Therefore, further well-conducted studies are warranted.
... Despite these concerns, vegan diets typically meet protein requirements and are characterized by lower saturated fat intake and higher beneficial unsaturated fat intake compared to omnivorous diets. Research has shown that adult vegans do not generally face risks of insufficient intake of vitamins A, B1, B6, B9 (folate), C, E, iron, phosphorus, magnesium, or copper [8,9]. ...
Plant-based diets, encompassing vegetarian, vegan, and flexitarian approaches, are gaining global attention due to their potential benefits for health, sustainability, and the environment. This review explores the multifaceted impacts of plant-based diets, offering a comprehensive understanding of their significance in addressing contemporary health and environmental challenges. The nutritional benefits of plant-based diets include a reduced risk of chronic diseases such as cardiovascular diseases, diabetes, and cancer, alongside positive effects on weight management. However, potential nutritional deficiencies in vitamin B12, iron, and omega-3 fatty acids require strategic interventions like food fortification and supplementation. The environmental advantages of plant-based diets are profound. These diets use fewer resources, generate lower greenhouse gas emissions, and contribute to biodiversity preservation compared to animal-based diets. Shifting toward plant-based eating can play a pivotal role in combating climate change and ensuring global food security for a growing population. Despite these benefits, challenges persist, including the environmental costs of monoculture farming, transportation emissions of plant-based products, and socioeconomic barriers like accessibility and affordability. This review also examines cultural and psychological factors that influence dietary choices, highlighting the importance of education and policy initiatives to overcome resistance and misinformation. Future directions include advancements in plant-based food technologies, such as lab-grown meats, and targeted policy interventions to promote sustainable dietary practices. In conclusion, adopting plant-based diets offers a promising pathway toward improved health, environmental sustainability, and resource efficiency. However, achieving widespread adoption requires overcoming barriers and addressing research gaps, necessitating coordinated efforts from individuals, policymakers, and researchers.
Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.
It is unclear regarding associations of dietary patterns with a wide range of chronic diseases and which dietary score is more predictive of major chronic diseases. Using the UK Biobank, we examine associations of four individual healthy dietary scores with the risk of 48 individual chronic diseases. Higher Alternate Mediterranean Diet score is associated with a lower risk of 32 (all 8 cardiometabolic disorders, 3 out of 10 types of cancers, 7 out of 10 psychological/neurological disorders, 5 out of 6 digestive disorders, and 9 out of 14 other chronic diseases). Alternate Healthy Eating Index-2010 and Healthful Plant-based Diet Index are inversely associated with the risk of 29 and 23 individual chronic diseases, respectively. A higher Anti-Empirical Dietary Inflammatory Index is associated with a lower risk of 14 individual chronic diseases and a higher incidence of two diseases. Our findings support dietary guidelines for the prevention of most chronic diseases.
Heart failure with reduced ejection fraction (HFrEF) and nonalcoholic fatty liver disease (NAFLD) are two common comorbidities that share similar pathophysiological mechanisms. There is a growing interest in the potential of targeted therapies to improve outcomes in patients with coexisting HFrEF and NAFLD. This manuscript reviews current and potential therapies for patients with coexisting HFrEF and NAFLD. Pharmacological therapies, including angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoids receptor antagonist, and sodium-glucose cotransporter-2 inhibitors, have been shown to reduce fibrosis and fat deposits in the liver. However, there are currently no data showing the beneficial effects of sacubitril/valsartan, ivabradine, hydralazine, isosorbide nitrates, digoxin, or beta blockers on NAFLD in patients with HFrEF. This study highlights the importance of considering HFrEF and NAFLD when developing treatment plans for patients with these comorbidities. Further research is needed in patients with coexisting HFrEF and NAFLD, with an emphasis on novel therapies and the importance of a multidisciplinary approach for managing these complex comorbidities.
Aims/hypothesis
Nordic dietary patterns that are high in healthy traditional Nordic foods may have a role in the prevention and management of diabetes. To inform the update of the EASD clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of Nordic dietary patterns and cardiometabolic outcomes.
Methods
We searched MEDLINE, EMBASE and The Cochrane Library from inception to 9 March 2021. We included prospective cohort studies and RCTs with a follow-up of ≥1 year and ≥3 weeks, respectively. Two independent reviewers extracted relevant data and assessed the risk of bias (Newcastle–Ottawa Scale and Cochrane risk of bias tool). The primary outcome was total CVD incidence in the prospective cohort studies and LDL-cholesterol in the RCTs. Secondary outcomes in the prospective cohort studies were CVD mortality, CHD incidence and mortality, stroke incidence and mortality, and type 2 diabetes incidence; in the RCTs, secondary outcomes were other established lipid targets (non-HDL-cholesterol, apolipoprotein B, HDL-cholesterol, triglycerides), markers of glycaemic control (HbA 1c , fasting glucose, fasting insulin), adiposity (body weight, BMI, waist circumference) and inflammation (C-reactive protein), and blood pressure (systolic and diastolic blood pressure). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence.
Results
We included 15 unique prospective cohort studies ( n =1,057,176, with 41,708 cardiovascular events and 13,121 diabetes cases) of people with diabetes for the assessment of cardiovascular outcomes or people without diabetes for the assessment of diabetes incidence, and six RCTs ( n =717) in people with one or more risk factor for diabetes. In the prospective cohort studies, higher adherence to Nordic dietary patterns was associated with ‘small important’ reductions in the primary outcome, total CVD incidence (RR for highest vs lowest adherence: 0.93 [95% CI 0.88, 0.99], p =0.01; substantial heterogeneity: I ² =88%, p Q <0.001), and similar or greater reductions in the secondary outcomes of CVD mortality and incidence of CHD, stroke and type 2 diabetes ( p <0.05). Inverse dose–response gradients were seen for total CVD incidence, CVD mortality and incidence of CHD, stroke and type 2 diabetes ( p< 0.05). No studies assessed CHD or stroke mortality. In the RCTs, there were small important reductions in LDL-cholesterol (mean difference [MD] −0.26 mmol/l [95% CI −0.52, −0.00], p MD =0.05; substantial heterogeneity: I ² =89%, p Q <0.01), and ‘small important’ or greater reductions in the secondary outcomes of non-HDL-cholesterol, apolipoprotein B, insulin, body weight, BMI and systolic blood pressure ( p< 0.05). For the other outcomes there were ‘trivial’ reductions or no effect. The certainty of the evidence was low for total CVD incidence and LDL-cholesterol; moderate to high for CVD mortality, established lipid targets, adiposity markers, glycaemic control, blood pressure and inflammation; and low for all other outcomes, with evidence being downgraded mainly because of imprecision and inconsistency.
Conclusions/interpretation
Adherence to Nordic dietary patterns is associated with generally small important reductions in the risk of major CVD outcomes and diabetes, which are supported by similar reductions in LDL-cholesterol and other intermediate cardiometabolic risk factors. The available evidence provides a generally good indication of the likely benefits of Nordic dietary patterns in people with or at risk for diabetes.
Registration
ClinicalTrials.gov NCT04094194.
Funding
Diabetes and Nutrition Study Group of the EASD Clinical Practice.
Graphical abstract
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.
Importance:
Several meta-analyses have summarized evidence for the association between dietary factors and the incidence of colorectal cancer (CRC). However, to date, there has been little synthesis of the strength, precision, and quality of this evidence in aggregate.
Objective:
To grade the evidence from published meta-analyses of prospective observational studies that assessed the association of dietary patterns, specific foods, food groups, beverages (including alcohol), macronutrients, and micronutrients with the incidence of CRC.
Data sources:
MEDLINE, Embase, and the Cochrane Library were searched from database inception to September 2019.
Evidence review:
Only meta-analyses of prospective observational studies with a cohort study design were eligible. Evidence of association was graded according to established criteria as follows: convincing, highly suggestive, suggestive, weak, or not significant.
Results:
From 9954 publications, 222 full-text articles (2.2%) were evaluated for eligibility, and 45 meta-analyses (20.3%) that described 109 associations between dietary factors and CRC incidence were selected. Overall, 35 of the 109 associations (32.1%) were nominally statistically significant using random-effects meta-analysis models; 17 associations (15.6%) demonstrated large heterogeneity between studies (I2 > 50%), whereas small-study effects were found for 11 associations (10.1%). Excess significance bias was not detected for any association between diet and CRC. The primary analysis identified 5 (4.6%) convincing, 2 (1.8%) highly suggestive, 10 (9.2%) suggestive, and 18 (16.5%) weak associations between diet and CRC, while there was no evidence for 74 (67.9%) associations. There was convincing evidence of an association of intake of red meat (high vs low) and alcohol (≥4 drinks/d vs 0 or occasional drinks) with the incidence of CRC and an inverse association of higher vs lower intakes of dietary fiber, calcium, and yogurt with CRC risk. The evidence for convincing associations remained robust following sensitivity analyses.
Conclusions and relevance:
This umbrella review found convincing evidence of an association between lower CRC risk and higher intakes of dietary fiber, dietary calcium, and yogurt and lower intakes of alcohol and red meat. More research is needed on specific foods for which evidence remains suggestive, including other dairy products, whole grains, processed meat, and specific dietary patterns.
Plant-based diets like vegetarian or vegan diets might influence circulating levels of inflammatory biomarkers, thereby reducing the risk of chronic diseases. This systematic review and meta-analysis aimed to investigate the associations of veganism and vegetarianism with circulating inflammatory biomarkers in comparison to omnivores. Literature search was conducted in Pubmed and EMBASE until April 2020 and mean differences of biomarkers were assessed for: C-reactive protein (CRP), interleukin-6 (IL-6), interleukin-18 (IL-18), interleukin-1 receptor antagonist (IL-1 RA), tumor necrosis factor-alpha (TNF-ɑ), E-selectin, intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), adiponectin, omentin-1 and resistin. Of initially identified 1073 publications, 21 cross-sectional studies met the inclusion criteria and were included in the systematic review and meta-analysis. Vegan diet was associated with lower levels of CRP compared to omnivores [mean difference − 0.54 mg/l, 95%-CI: − 0.79 to − 0.28, p < 0.0001]. This association was less pronounced in vegetarians [mean difference − 0.25 mg/l, 95%-CI: − 0.49 to 0.00, p = 0.05]. In patients with impaired kidney function, the association between vegetarian nutrition and CRP was much stronger with − 3.91 mg/l (95%-CI: − 5.23 to − 2.60; p < 0.0001). No substantial effects were observed for all other inflammatory biomarkers. Despite strong associations between CRP and a vegan or vegetarian diet were seen, further research is needed, as most inflammatory biomarkers were investigated only in single studies so far.
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.
This systematic review and meta-analysis aimed to explore the association between the Mediterranean dietary pattern and inflammation in older adults. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A search of the literature was conducted up to June 2020 in 7 electronic databases, namely PubMed, Embase, Web of Science, Scopus, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and ProQuest. The Joanna Briggs Institute Critical Appraisal Checklists and the Newcastle-Ottawa Scale were used to assess the methodological quality. The overall standardized mean difference (SMD) and 95% CIs were estimated in random-effects meta-analyses. Thirteen studies were identified as having acceptable quality and were included in this systematic review: 3 randomized controlled trials (RCTs), 1 quasi-experimental study, 1 cohort study, and 8 cross-sectional studies. The circulating C-reactive protein (CRP) concentration was the most common inflammation indicator used. Results of the meta-analysis on 5 cross-sectional studies revealed a significant inverse association between the Mediterranean dietary pattern and inflammation as assessed by CRP (SMD = -0.26; 95% CI: -0.41, -0.11; P < 0.001). Other studies that investigated a variety of inflammation indicators other than CRP showed mixed results with regard to the relation between the Mediterranean dietary pattern and inflammation in older adults. Our findings suggest that the Mediterranean dietary pattern may be associated with lower inflammation in older adults. However, more long-term RCTs are required to demonstrate the effects of the Mediterranean dietary pattern on multiple inflammation parameters in older adults. The study has been registered on PROSPERO (#CRD42020140145).
While the pathophysiology of chronic disorders varies there are three basic mechanisms - inflammation, oxidative stress and endothelial dysfunction – that are common in many chronic diseases. However, the failure of these mechanisms to work synchronously can lead to morbidity complicating the course of many chronic diseases. We analyzed data of 178 patients from cohorts with selected chronic diseases in this quasi-experimental study. Endothelial dysfunction was determined by flow-mediated dilatation (FMD) and asymmetric dimethylarginine (ADMA) levels. Serum ADMA, high sensitive C-reactive protein (hs-CRP), serum PTX3, malondialdehyde (MDA), Cu/Zn-superoxide dismutase (Cu/Zn-SOD), glutathione peroxidase (GSH-Px) levels and FMD were studied in baseline and after 12 weeks of Morinda citrifolia (anti-atherosclerotic liquid- AAL), omega-3 (anti-inflammatory capsules- AIC) and extract with Alaskan blueberry (anti-oxidant liquid- AOL). Stepwise multivariate regression analysis was used to evaluate the association of FMD with clinical and serologic parameters. Serum ADMA, MDA, PTX3, hsCRP and albumin levels, and proteinuria were significantly decreased while CuZn-SOD, GSH-Px and FMD levels were significantly increased following AAL, AIC and AOL therapies. The FMD was negatively correlated with serum ADMA, MDA, PTX3, and hsCRP levels and positively correlated with CuZn-SOD and eGFR levels. ADMA and PTX3 levels were independently related to FMD both before and after AAL, AIC and AOL therapies. Our study shows that serum ADMA, MDA, PTX3 levels are associated with endothelial dysfunction in patients with selected chronic diseases. In addition, short-term AAL, AIC and AOL therapies significantly improves a number of parameters in our cohort and can normalize ADMA, PTX3, hsCRP and MDA levels.
Selected Conference Proceedings of the VIIIth Barcelona International Congress on the Mediterranean Diet, Barcelona, Spain, 24–25th March 2010)
Objective
The objective of this study was to evaluate the effect of skipping breakfast on body composition and cardiometabolic risk factors.
Methods
This study conducted a systematic review and meta‐analysis of randomized controlled trials (RCTs) evaluating breakfast skipping compared with breakfast consumption. Inclusion criteria included age ≥ 18, intervention duration ≥ 4 weeks, ≥ 7 participants per group, and ≥ 1 body composition measure. Random‐effects meta‐analyses of the effect of breakfast skipping on body composition and cardiometabolic risk factors were performed.
Results
Seven RCTs (n = 425 participants) with an average duration of 8.6 weeks were included. Compared with breakfast consumption, breakfast skipping significantly reduced body weight (weighted mean difference [WMD] = −0.54 kg [95% CI: −1.05 to −0.03], P = 0.04, I² = 21.4%). Percent body fat was reported in 5 studies and was not significantly different between breakfast skippers and consumers. Three studies reported on low‐density lipoprotein cholesterol (LDL), which was increased in breakfast skippers as compared with breakfast consumers (WMD = 9.24 mg/dL [95% CI: 2.18 to 16.30], P = 0.01). Breakfast skipping did not lead to significant differences in blood pressure, total cholesterol, high‐density lipoprotein (HDL) cholesterol, triglycerides, C‐reactive protein, insulin, fasting glucose, leptin, homeostatic model assessment of insulin resistance, or ghrelin.
Conclusions
Breakfast skipping may have a modest impact on weight loss and may increase LDL in the short term. Further studies are needed to provide additional insight into the effects of breakfast skipping.
Background
Fibre is promoted as part of a healthy dietary pattern and in diabetes management. We have considered the role of high-fibre diets on mortality and increasing fibre intake on glycaemic control and other cardiometabolic risk factors of adults with prediabetes or diabetes.
Methods and findings
We conducted a systematic review of published literature to identify prospective studies or controlled trials that have examined the effects of a higher fibre intake without additional dietary or other lifestyle modification in adults with prediabetes, gestational diabetes, type 1 diabetes, and type 2 diabetes. Meta-analyses were undertaken to determine the effects of higher fibre intake on all-cause and cardiovascular mortality and increasing fibre intake on glycaemic control and a range of cardiometabolic risk factors. For trials, meta regression analyses identified further variables that influenced the pooled findings. Dose response testing was undertaken; Grading of Recommendations Assessment, Development and Evaluation (GRADE) protocols were followed to assess the quality of evidence. Two multicountry cohorts of 8,300 adults with type 1 or type 2 diabetes followed on average for 8.8 years and 42 trials including 1,789 adults with prediabetes, type 1, or type 2 diabetes were identified. Prospective cohort data indicate an absolute reduction of 14 fewer deaths (95% confidence interval (CI) 4–19) per 1,000 participants over the study duration, when comparing a daily dietary fibre intake of 35 g with the average intake of 19 g, with a clear dose response relationship apparent. Increased fibre intakes reduced glycated haemoglobin (HbA1c; mean difference [MD] −2.00 mmol/mol, 95% CI −3.30 to −0.71 from 33 trials), fasting plasma glucose (MD −0.56 mmol/L, 95% CI −0.73 to −0.38 from 34 trials), insulin (standardised mean difference [SMD] −2.03, 95% CI −2.92 to −1.13 from 19 trials), homeostatic model assessment of insulin resistance (HOMA IR; MD −1.24 mg/dL, 95% CI −1.72 to −0.76 from 9 trials), total cholesterol (MD −0.34 mmol/L, 95% CI −0.46 to −0.22 from 27 trials), low-density lipoprotein (LDL) cholesterol (MD −0.17 mmol/L, 95% CI −0.27 to −0.08 from 21 trials), triglycerides (MD −0.16 mmol/L, 95% CI −0.23 to −0.09 from 28 trials), body weight (MD −0.56 kg, 95% CI −0.98 to −0.13 from 18 trials), Body Mass Index (BMI; MD −0.36, 95% CI −0·55 to −0·16 from 14 trials), and C-reactive protein (SMD −2.80, 95% CI −4.52 to −1.09 from 7 trials) when compared with lower fibre diets. All trial analyses were subject to high heterogeneity. Key variables beyond increasing fibre intake were the fibre intake at baseline, the global region where the trials were conducted, and participant inclusion criteria other than diabetes type. Potential limitations were the lack of prospective cohort data in non-European countries and the lack of long-term (12 months or greater) controlled trials of increasing fibre intakes in adults with diabetes.
Conclusions
Higher-fibre diets are an important component of diabetes management, resulting in improvements in measures of glycaemic control, blood lipids, body weight, and inflammation, as well as a reduction in premature mortality. These benefits were not confined to any fibre type or to any type of diabetes and were apparent across the range of intakes, although greater improvements in glycaemic control were observed for those moving from low to moderate or high intakes. Based on these findings, increasing daily fibre intake by 15 g or to 35 g might be a reasonable target that would be expected to reduce risk of premature mortality in adults with diabetes.
The purpose of this systematic review and meta-analysis was to investigate omega-3 fatty acids’ influence on 12 inflammatory biomarkers—LDL, HDL, total cholesterol, TG, HbA1c, Apo AI, Apo AII, Apo B, CRP, TNF-α, glucose, and fasting blood glucose among diabetic and cardiovascular disease (CVD) patients. We searched articles in six database engines, and 16 of the 696 articles reviewed met the inclusion criteria. Among these, lipid and inflammatory biomarkers investigated commonly included total cholesterol (11 studies), LDL, and TG (10 studies each). Overall, omega-3 was associated with a significant reduction in Apo AII among diabetic patients, as compared to different controls (−8.0 mg/dL 95% CI: −12.71, −3.29, p = 0.0009), triglycerides (−44.88 mg/dL 95% CI: −82.6, −7.16, p < 0.0001), HDL (−2.27 mg/dL 95% CI: −3.72, −0.83, p = 0.002), and increased fasting blood glucose (16.14 mg/dL 95% CI: 6.25, 26.04, p = 0.001). Omega-3 also was associated with increased LDL among CVD patients (2.10 mg/dL 95% CI: 1.00, 3.20, p = 0.0002). We conclude that omega-3 fatty acids may be associated with lower inflammatory biomarkers among diabetic and cardiovascular patients. Clinicians should be aware of these potential benefits; however, it is essential to recommend that patients consult with clinicians before any omega-3 intake.
There is some evidence supporting the beneficial effects of a Paleolithic Diet (PD) on cardiovascular disease risk factors. This diet advises consuming lean meat, fish, vegetables, fruits, and nuts and avoiding intake of grains, dairy products, processed foods, and added sugar and salt. This study was performed to assess the effects of a PD on cardiovascular disease risk factors including anthropometric indexes, lipid profile, blood pressure, and inflammatory markers using data from randomized controlled trials. A comprehensive search was performed in the PubMed, Scopus, ISI Web of Science, and Google Scholar databases up to August, 2018. A meta-analysis was performed using a random-effects model to estimate the pooled effect size. Meta-analysis of 8 eligible studies revealed that a PD significantly reduced body weight [weighted mean difference (WMD) = −2.17 kg; 95% CI: −3.48, −0.87 kg], waist circumference (WMD = −2.90 cm; 95% CI: −4.51, −1.28 cm), body mass index (in kg/m 2) (WMD = −1.15; 95% CI: −1.68, −0.62), body fat percentage (WMD = −1.38%; 95% CI: −2.08%, −0.67%), systolic (WMD = −4.24 mm Hg; 95% CI: −7.11, −1.38 mm Hg) and diastolic (WMD = −2.95 mm Hg; 95% CI: −4.72, −1.18 mm Hg) blood pressure, and circulating concentrations of total cholesterol (WMD = −0.22 mg/dL; 95% CI: −0.42, −0.03 mg/dL), TGs (WMD = −0.23 mg/dL; 95% CI: −0.46, −0.01 mg/dL), LDL cholesterol (WMD = −0.13 mg/dL; 95% CI: −0.25, −0.01 mg/dL), and C-reactive protein (CRP) (WMD = −0.41 mg/L; 95% CI: −0.81, −0.008 mg/L) and also significantly increased HDL cholesterol (WMD = 0.05 mg/dL; 95% CI: 0.005, 0.10 mg/dL). However, sensitivity analysis revealed that the overall effects of a PD on lipid profile, blood pressure, and circulating CRP concentrations were significantly influenced by removing some studies, hence the results must be interpreted with caution. Although the present meta-analysis revealed that a PD has favorable effects on cardiovascular disease risk factors, the evidence is not conclusive and more well-designed trials are still needed. Adv Nutr 2019;0:1-13.
The difference in gut microbiota composition between individuals following vegan or vegetarian diets and those following omnivorous diets is well documented. A plant-based diet appears to be beneficial for human health by promoting the development of more diverse and stable microbial systems. Additionally, vegans and vegetarians have significantly higher counts of certain Bacteroidetes-related operational taxonomic units compared to omnivores. Fibers (that is, non-digestible carbohydrates, found exclusively in plants) most consistently increase lactic acid bacteria, such as Ruminococcus, E. rectale, and Roseburia, and reduce Clostridium and Enterococcus species. Polyphenols, also abundant in plant foods, increase Bifidobacterium and Lactobacillus, which provide anti-pathogenic and anti-inflammatory effects and cardiovascular protection. High fiber intake also encourages the growth of species that ferment fiber into metabolites as short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate. The positive health effects of SCFAs are myriad, including improved immunity against pathogens, blood–brain barrier integrity, provision of energy substrates, and regulation of critical functions of the intestine. In conclusion, the available literature suggests that a vegetarian/vegan diet is effective in promoting a diverse ecosystem of beneficial bacteria to support both human gut microbiome and overall health. This review will focus on effects of different diets and nutrient contents, particularly plant-based diets, on the gut microbiota composition and production of microbial metabolites affecting the host health.
Dietary patterns with substantial proportions of energy from plant sources have been associated with favorable biomarkers of low-grade inflammation. Less is known of the relation between vegetarian-based dietary patterns and markers of inflammation and immune status. This systematic review and meta-analysis aimed to determine the relation between vegetarian-based dietary patterns and inflammatory and immune markers (C-reactive protein; (CRP), tumour necrosis factor-alpha (TNF-α), fibrinogen, natural killer cells, leukocytes, lymphocytes, thrombocytes, interleukins and immune globulins). PubMed, Medline and Cochrane scientific databases were searched to identify relevant studies. Random effects meta-analyses were conducted to assess the weighted mean differences (WMD) for each outcome variable between vegetarian and non-vegetarian groups. Thirty observational and ten intervention studies were included in the review. Pooled effects of vegetarian-based dietary patterns were associated with significantly lower concentrations of CRP (WMD: -0.61 mg/L; 95% CI: -0.91, -0.32; P = 0.0001), fibrinogen (WMD: -0.22 g/L; 95% CI: -0.41, -0.04; P = 0.02) and total leukocyte (WMD: -0.62 x103/μL; 95% CI -1.13, -0.10; P = 0.02) compared to those following non-vegetarian dietary patterns in observational studies. Insufficient data was identified for a meta-analysis of intervention studies. This study provides evidence that vegetarian-based dietary patterns are associated with lowered serum CRP, fibrinogen and total leukocyte concentrations. Future research should focus on large scale intervention trials, contrasting differences in inflammation and immune status and function between vegetarian and non-vegetarian based populations.
Objective
Evidence syntheses such as systematic reviews and meta-analyses provide a rigorous and transparent knowledge base for translating clinical research into decisions, and thus they represent the basic unit of knowledge in medicine. Umbrella reviews are reviews of previously published systematic reviews or meta-analyses. Therefore, they represent one of the highest levels of evidence synthesis currently available, and are becoming increasingly influential in biomedical literature. However, practical guidance on how to conduct umbrella reviews is relatively limited.
Methods
We present a critical educational review of published umbrella reviews, focusing on the essential practical steps required to produce robust umbrella reviews in the medical field.
Results
The current manuscript discusses 10 key points to consider for conducting robust umbrella reviews. The points are: ensure that the umbrella review is really needed, prespecify the protocol, clearly define the variables of interest, estimate a common effect size, report the heterogeneity and potential biases, perform a stratification of the evidence, conduct sensitivity analyses, report transparent results, use appropriate software and acknowledge the limitations. We illustrate these points through recent examples from umbrella reviews and suggest specific practical recommendations.
Conclusions
The current manuscript provides a practical guidance for conducting umbrella reviews in medical areas. Researchers, clinicians and policy makers might use the key points illustrated here to inform the planning, conduction and reporting of umbrella reviews in medicine.
Background:
The evidence for the Portfolio dietary pattern, a plant-based dietary pattern that combines recognized cholesterol-lowering foods (nuts, plant protein, viscous fibre, plant sterols), has not been summarized.
Objective:
To update the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of controlled trials using GRADE of the effect of the Portfolio dietary pattern on the primary therapeutic lipid target for cardiovascular disease prevention, low-density lipoprotein cholesterol (LDL-C), and other established cardiometabolic risk factors.
Methods:
We searched MEDLINE, EMBASE, and The Cochrane Library through April 19, 2018. We included controlled trials ≥ 3-weeks assessing the effect of the Portfolio dietary pattern on cardiometabolic risk factors compared with an energy-matched control diet free of Portfolio dietary pattern components. Two independent reviewers extracted data and assessed risk of bias. The primary outcome was LDL-C. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q statistic) and quantified (I2-statistic). GRADE assessed the certainty of the evidence.
Results:
Eligibility criteria were met by 7 trial comparisons in 439 participants with hyperlipidemia, in which the Portfolio dietary pattern was given on a background of a National Cholesterol Education Program (NCEP) Step II diet. The combination of a portfolio dietary pattern and NCEP Step II diet significantly reduced the primary outcome LDL-C by ~17% (MD, -0.73mmol/L, [95% CI, -0.89 to -0.56 mmol/L]) as well as non-high-density lipoprotein cholesterol, apolipoprotein B, total cholesterol, triglycerides, systolic and diastolic blood pressure, C-reactive protein, and estimated 10-year coronary heart disease (CHD) risk, compared with an NCEP Step 2 diet alone (P<0.05). There was no effect on high-density lipoprotein cholesterol or body weight. The certainty of the evidence was high for LDL-cholesterol and most lipid outcomes and moderate for all others outcomes.
Conclusions:
Current evidence demonstrates that the Portfolio dietary pattern leads to clinically meaningful improvements in LDL-C as well as other established cardiometabolic risk factors and estimated 10-year CHD risk.
Consuming a Mediterranean diet rich in minimally processed plant foods has been associated with a reduced risk of developing multiple chronic diseases and increased life expectancy. Data from several randomized clinic trials have demonstrated a beneficial effect in the primary and secondary prevention of cardiovascular disease, type 2 diabetes, atrial fibrillation and breast cancer. The exact mechanism by which an increased adherence to the traditional Mediterranean diet exerts its favorable effects is not known. However, accumulating evidence indicates that the five most important adaptations induced by the Mediterranean dietary pattern are: (1) lipid lowering effect, (2) protection against oxidative stress, inflammation and platelet aggregation, (3) modification of hormones and growth factors involved in the pathogenesis of cancer, (4) inhibition of nutrient sensing pathways by specific amino acid restriction, and (4) gut microbiota-mediated production of metabolites influencing metabolic health. More studies are needed to understand how single modifications of nutrients typical of the Mediterranean diet interact with energy intake, energy expenditure, and the microbiome in modulating the key mechanisms that promote cellular, tissue, and organ health during aging.
The number of published systematic reviews of studies of healthcare interventions has increased rapidly and these are used extensively for clinical and policy decisions. Systematic reviews are subject to a range of biases and increasingly include non-randomised studies of interventions. It is important that users can distinguish high quality reviews. Many instruments have been designed to evaluate different aspects of reviews, but there are few comprehensive critical appraisal instruments. AMSTAR was developed to evaluate systematic reviews of randomised trials. In this paper, we report on the updating of AMSTAR and its adaptation to enable more detailed assessment of systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. With moves to base more decisions on real world observational evidence we believe that AMSTAR 2 will assist decision makers in the identification of high quality systematic reviews, including those based on non-randomised studies of healthcare interventions.
Background
Type 2 diabetes is emerging in Sudan and is associated with obesity. Deregulated lipid metabolism and inflammatory states are suggested risk factors for cardiovascular disease, which is a leading cause of diabetic death. This study aimed to investigate C-reactive protein (CRP) levels and the lipid profile in type 2 diabetic adult Sudanese compared with nondiabetics, and to test their associations with other characteristics.
Methods
A cross-sectional study including 70 diabetics and 40 nondiabetics was conducted. Anthropometric measurements were assessed, and demographic and medical data were obtained using a structured questionnaire. Blood specimens were collected and biochemical parameters were analyzed applying standard methods.
Results
CRP and triglycerides were significantly higher in the diabetic group (P<0.001 and P=0.01, respectively). Differences in total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were not statistically significant between the diabetic and nondiabetic groups. In the diabetic group, correlation analysis revealed that the CRP level had a significant positive correlation with LDL-C (r=0.255, P=0.034) and body mass index (r=0.29, P=0.016). Body mass index showed a significant positive correlation with triglycerides (r=0.386, P=0.001). Within the lipid parameters, a number of significant correlations were observed. Elevated levels of CRP, LDL-C, and triglycerides were markedly more prevalent in the diabetic group of patients. Diabetics showed significantly higher CRP levels compared with nondiabetics (odds ratio 5.56, P=0.001).
Conclusion
The high prevalence of obesity among diabetics, together with elevated levels of triglycerides and CRP, suggest coexistence of dyslipidemia and inflammation in diabetes. Our findings emphasize that diabetics were 5.6 times more likely to have high CRP levels than nondiabetics; as CRP is a predictor of cardiovascular disease risk, it can be recognized that diabetics are at more risk of cardiovascular disease than nondiabetics. Considering evaluation of CRP together with the lipid profile in prediction of cardiovascular disease risk in Sudanese diabetics should be further tested in large-scale studies.
With the definition of goals in Nutrition Science, we are taking a brave step and a leap of faith with regard to predicting the scope and direction of nutrition science over the next 5 years. The content of this editorial has been discussed, refined, and evaluated with great care by the Frontiers in Nutrition editorial board. We feel the topics described represent the key opportunities, but also the biggest challenges in our field. We took a clean-slate, bottom-up approach to identify and address these topics and present them in eight categories.
For each category, the authors listed take responsibility, and deliberately therefore this document is a collection of thoughts from active minds, rather than a complete integration or consensus.
At Frontiers in Nutrition, we are excited to develop and share a platform for this discussion. Healthy Nutrition for all – an ambition too important to be handled by detached interest groups and behind closed doors.
Low-grade chronic inflammation is an underlying pathophysiological mechanism linking risk factors and/or metabolic disorders to increased risk of chronic degenerative disease. A meat-based pattern, as the Western type diet, is positively linked to higher levels of some important biomarkers of inflammation, such as C-reactive protein (CRP), interleukin-6 and fibrinogen. Conversely, a Mediterranean-like eating behavior is associated with lower degree of these biomarkers thus suggesting an anti-inflammatory action of its main food components. This chapter goes through the most important investigations addressing the relationship between dietary habits and subclinical inflammation. Attention was focussed on the findings from the Moli-sani study: this is a large prospective cohort study that recruited 24,325 men and women from the general population of the Molise Region, a Southern Italian area, with the aim of investigating genetic and environmental risk/protection factors for cardiovascular and tumor disease. For the first time, the Moli-sani study carefully investigated the Mediterranean diet as an environmental determinant of both platelet and white blood cell counts, starting from the hypothesis that a diet rich in healthy compounds could favorably influence the production and/or the clearance of these two cellular biomarkers of lowgrade inflammation. Additionally, evidence from this large Italian cohort showed that a Mediterranean-like diet was closely associated with relatively lower values of glucose, lipids, CRP, blood pressure and 10-year cardiovascular risk, while the consumption of healthy foods with high rather than low content in antioxidant vitamins and phytochemicals was associated with lower blood pressure and CRP plasma levels at least in men.
Abstract Previous studies suggested that dietary fiber intake may have a lowing effect on circulating C-reactive protein (CRP) level, a sensitive marker of inflammation, in overweight/obese adults with inconsistent results. A literature search was performed in April 2014 for related randomized controlled trials (RCTs) and meta-analysis was conducted. Meta-analysis including 14 RCTs showed that intervention with dietary fiber or fiber-rich food, compared with control, produced a slight, but significant reduction of 0.37 mg/L (95% CI -0.74, 0) in circulating CRP level among this population. Subgroup analyses showed that such a significant reduction was only observed after combining studies where the total fiber intake was 8 g/d higher in the intervention group than in the control group. No obvious heterogeneity and publication bias were found in the meta-analysis. In conclusion, this meta-analysis provides evidence that dietary fiber or food naturally rich in fiber has beneficial effects on circulating CRP level in overweight/obese adults.
Significance
We present an unusual mechanism for the well-known association between red meat consumption and carcinoma risk involving the nonhuman sialic acid N -glycolylneuraminic acid (Neu5Gc). We first evaluate the Neu5Gc content of various foods to show that red meats are particularly rich in orally bioavailable Neu5Gc and then investigate human-like Neu5Gc-deficient mice fed this form of Neu5Gc. When such mice were challenged with anti-Neu5Gc antibodies, they developed evidence of systemic inflammation. Long-term exposure to this combination resulted in a significantly higher incidence of carcinomas (five-fold increase) and an association with Neu5Gc accumulation in the tumors. Similar mechanisms may contribute to the association of red meat consumption with other diseases, such as atherosclerosis and type 2 diabetes, which are also exacerbated by inflammation.
Advances in our understanding of the mechanisms that bring about the resolution of acute inflammation have uncovered a new genus of pro-resolving lipid mediators that include the lipoxin, resolvin, protectin and maresin families, collectively called specialized pro-resolving mediators. Synthetic versions of these mediators have potent bioactions when administered in vivo. In animal experiments, the mediators evoke anti-inflammatory and novel pro-resolving mechanisms, and enhance microbial clearance. Although they have been identified in inflammation resolution, specialized pro-resolving mediators are conserved structures that also function in host defence, pain, organ protection and tissue remodelling. This Review covers the mechanisms of specialized pro-resolving mediators and omega-3 essential fatty acid pathways that could help us to understand their physiological functions.
To monitor inflammation in a meaningful way, the markers used must be valid: they must reflect the inflammatory process under study and they must be predictive of future health status. In 2009, the Nutrition and Immunity Task Force of the International Life Sciences Institute, European Branch, organized an expert group to attempt to identify robust and predictive markers, or patterns or clusters of markers, which can be used to assess inflammation in human nutrition studies in the general population. Inflammation is a normal process and there are a number of cells and mediators involved. These markers are involved in, or are produced as a result of, the inflammatory process irrespective of its trigger and its location and are common to all inflammatory situations. Currently, there is no consensus as to which markers of inflammation best represent low-grade inflammation or differentiate between acute and chronic inflammation or between the various phases of inflammatory responses. There are a number of modifying factors that affect the concentration of an inflammatory marker at a given time, including age, diet and body fatness, among others. Measuring the concentration of inflammatory markers in the bloodstream under basal conditions is probably less informative compared with data related to the concentration change in response to a challenge. A number of inflammatory challenges have been described. However, many of these challenges are poorly standardised. Patterns and clusters may be important as robust biomarkers of inflammation. Therefore, it is likely that a combination of multiple inflammatory markers and integrated readouts based upon kinetic analysis following defined challenges will be the most informative biomarker of inflammation.
Background
Time-restricted eating (TRE) may facilitate weight loss, but its impact on inflammation remains unclear. Chronic inflammation can detrimentally increase risk of obesity-associated comorbidities.
Objectives
The aim of this systematic review was to synthesize and determine the effects of TRE on cytokine and adipokines (C-reactive protein [CRP], TNF alpha [TNF-α], interleukin-6 [IL-6], leptin, and adiponectin) in adults.
Methods
PubMed, Scopus, Cochrane CENTRAL, and Web of Science were systematically searched for randomized controlled trials (RCTs) and non-RCTs to determine the effects of TRE on cytokines and adipokines in adults up to 23 June, 2023. Risk of bias was assessed using risk of Bias 2 tool for RCTs and the ROBINS-I for non-RCTs. The standardized mean differences (SMDs) and their 95% confidence intervals (CIs) were estimated with the DerSimonian–Laird method through random-effect models. The PRISMA recommendations were followed.
Results
A total of 25 studies (13 RCTs, 12 non-RCTs) involving 936 participants were included. The pooled SMD for the effect of TRE compared with the control group on cytokines and adipokines was −0.11 (95% CI: −0.33, 0.12; I2 = 19.7%; n = 10 comparisons) for CRP; −0.25 (95% CI: −0.47, −0.03; I2 = 0%; n = 11 comparisons) for TNF-α; −0.09 (95% CI: −0.39, 0.21; I2 = 16.4%; n = 8 comparisons) for IL-6; −0.81 (95% CI: −1.37, −0.24; I2 = 65.3%; n = 5 comparisons) for leptin; and 0.07 (95% CI: −0.40, 0.54; I2 = 56.9%; n = 6 comparisons) for adiponectin.
Conclusions
Time-restricted eating may be an effective approach to reduce TNF-α and leptin levels in the general adult population.
This review was registered at PROSPERO as CRD42022358162.
In this systematic review and meta-analysis of clinical controlled trials (CCTs) we aimed to investigate the efficacy of KDs as an adjuvant therapy on cardiometabolic outcomes in patient with cancer compared to conventional non-ketogenic diets. Only CCTs involving cancer patients that were assigned to either a KD or a standard diet control group were selected. Two reviewers independently extracted the data, and a meta-analysis was performed using a random effects model to estimate weighted mean differences (WMDs) and confidence intervals (CIs) in body composition, metabolite, lipid profile, liver and kidney function parameters and quality of life. This meta-analysis showed a significant reduction in body weight (WMD= −2.99 kg; 95% CI: −4.67, −1.31; and P < 0.001), BMI (WMD= −1.08 kg/m 2 ; 95% CI: −1.81, −0.34; P ≤ 0.002) and fat mass (WMD= −1.48 kg; 95% CI: −2.56, −0.40; and P = 0.007) by a KD. KDs significantly decreased glucose (WMD= −5.22 mg/dl; 95% CI: −9.0, −1.44; and P = 0.007), IGF-1 (WMD= −17.52 ng/ml; 95% CI: −20.24, −14.8; and P ˂0.001) and triglyceride (WMD= −24.46 mg/dl; 95% CI: −43.96, −4.95; and P = 0.014) levels. Furthermore, KDs induced ketosis by increasing β-hydroxybutyrate (WMD= 0.56 mmol/l; 95% CI: 0.37, 0.75; and P < 0.001). There were non-significant pooled effects of KDs on improving insulin, C-reactive protein and cholesterol levels and kidney and liver function. Emotional functioning was even increased significantly in the KD compared to the SD groups. In summary we found that KDs result in a greater reduction in glucose, IGF-1, triglycerides, body weight, BMI, and fat mass in cancer patients compared to traditional non-ketogenic diets and improved emotional functioning. The quality of evidence in the meta-analysis was moderate according to the Nutrigrade assessment.
Background and aims
Chronic inflammation in obese patients can be managed through a calorie-restricted diet, characterized by reduced C - reactive protein (CRP). This study aims to assess the role of such diet on CRP.
Methods
Literature searches were performed using search engines. Randomized controlled trials were included. Calorie-restricted diets in combination with non-diet interventions were excluded.
Results
Calorie restriction decreased CRP in obese patients with a mean difference of −0.22 (95% CI -0.40 to −0.04, p 0.006).
Conclusions
Calorie-restricted diet reduces CRP. Diet administration >12 weeks had a beneficial effect.
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.
Abstract
The transition of Sub-Saharan Africans from rural settings and traditional plant-rich diets to urban settings and calorie-dense Westernized diets has led to specific shifts in serum metabolites and activates a heightened proinflammatory state in immune cells.
Background
While the pathophysiology of chronic disorders varies there are three basic mechanisms - inflammation, oxidative stress and endothelial dysfunction – that are common in many chronic diseases. These mechanisms, which have a dynamic structure, are key to homeostasis. However, the failure of these mechanisms to work synchronously can lead to morbidity complicating the course of many chronic diseases.
Objectives
To evaluate the effect of anti-atherosclerotic liquid (AAL), anti-inflammatory capsules (AIC) and anti-oxidant liquid (AOL) supplementation on the flow-mediated dilatation (FMD), inflammatory, oxidative stress and endothelial dysfunction markers in patients with selected chronic diseases
Methods
We analyzed data of 178 patients from cohorts with selected chronic diseases (Rheumatoid arthritis, familial Mediterranean fever, DM type-2, Hypertension, Multiple sclerosis, Chronic obstructive pulmonary disease, Alzheimer disease and Cancer) in this quasi-experimental study. Endothelial dysfunction was determined by FMD and serum asymmetric dimethylarginine (ADMA) levels. Serum ADMA, high sensitive C-reactive protein (hs-CRP), serum PTX3, malondialdehyde (MDA), Cu/Zn-superoxide dismutase (Cu/Zn-SOD), glutathione peroxidase (GSH-Px) levels and FMD were studied in baseline and after 12 weeks of Morinda citrifolia (AAL, 3 ml once per day), omega-3 (AIC, 3 capsules once per day) and extract with Alaskan blueberry and 21 different red purple fruit vegetables (AOL, 30 ml once per day). Stepwise multivariate regression analysis evaluated the association of FMD with clinical and serologic parameters.
Results
Serum ADMA, MDA, PTX3, hsCRP and albumin levels, and proteinuria were significantly decreased and CuZn-SOD, GSH-Px and FMD levels were significantly increased following AAL, AIC and AOL therapies. FMD was negatively correlated with serum ADMA, MDA, PTX3, hsCRP levels, SBP and DBP and positively correlated to CuZn-SOD and eGFR levels both at baseline and after the 12-weeks treatment period. Multivariate regression analysis revealed that ADMA and PTX3 levels were independently related to FMD both before and after AAL, AIC and AOL therapies (Table 1, Figure 1).
Conclusion
Our study shows that serum ADMA, MDA, PTX3 levels are associated with endothelial dysfunction in patients with selected chronic diseases. Short-term AAL, AIC and AOL therapies significantly improves FMD and normalizes ADMA, PTX3, hsCRP and MDA. This may have implications for adjunctive therapy in a number of chronic disorders.
References
[1] Yilmaz MI, Saglam M, Caglar K, Cakir E, Sonmez A, Ozgurtas T et al. The determinants of endothelial dysfunction in CKD: oxidative stress and asymmetric dimethylarginine. Am J Kidney Dis. 2006;47(1):42-50. doi:10.1053/j.ajkd.2005.09.029.
Disclosure of Interests
None declared
Objective: Several randomized clinical trials (RCTs) have investigated the effects of the Paleolithic
diet (PD) in adult patients suffering from metabolic disorders. However, the results of these RCTs
are conflicting. Therefore, we conducted a systematic review and meta-analysis to assess the
effects of the PD in patients with metabolic disorders.
Methods: We searched the PubMed/Medline, Scopus, Cochrane Databases, Google Scholar, Web
of Science, and Embase databases up to June, 2020. The data were pooled using a random-effects
model. From the eligible publications, 10 articles were selected for inclusion in this systematic
review and meta-analysis. The meta-analysis was performed using a random-effects model. The
heterogeneity was determined using the I2 statistics and the Cochrane Q test.
Results: The pooled results from the random-effects model showed a significant reduction of the
homeostatic model assessment of insulin resistance (HOMA-IR) (weighted mean difference, WMD:
�0.39, 95% CI: �0.70, �0.08), fasting insulin (WMD: �12.17 lU/mL, 95% CI: �24.26, �0.08), total
cholesterol (WMD: �0.32 mmol/l, 95% CI: �0.49, �0.15), triglycerides (WMD: �0.29 mmol/L, 95%
CI: �0.42, �0.16), low-density lipoprotein cholesterol (WMD: �0.35 mmol/L, 95% CI: �0.67, �0.03),
blood pressure (BP)(WMD � 5.89 mmHg; 95% CI � 9.973 to � 1.86 for the systolic BP and WMD
� 4.01 mmHg; 95% CI � 6.21 to � 1.80 for the diastolic BP values) and C-reactive protein (CRP)
levels (WMD: �0.84, mg/L, 95% CI: �1.62, �0.06) in the PD group versus control group.
Conclusions: Our findings provide better insights into the effect of the PD on the modulation of
the glucose and lipid metabolism factors in patients with metabolic disorders, providing comprehensive information for the development of future RCTs with a high quality design.
Purpose
Intermittent fasting (IF) and energy-restricted diets (ERDs) have emerged as dietary approaches to decrease the inflammatory status; however, there are no consistent results regarding humans. In order to achieve a comprehensive conclusion, we aimed to conduct a meta-analysis of randomized control trials (RCTs) to evaluate the effects of IF or ERDs on plasma concentrations of inflammatory biomarkers.
Methods
We systematically searched online medical databases including Web of Sciences, PubMed, SCOPUS, and Google Scholar up to June 2019. Evaluations of effect sizes were described employing in weighted mean difference (WMD) and 95% confidence interval (CI) from the random-effects model.
Findings
Eighteen eligible RCTs were included in this meta-analysis. The pooled estimation from the random-effect model showed that IF regimens and ERDs significantly reduced C-reactive protein (CRP) concentrations (WMD: -0.024 mg/dl; 95% CI: -0.044 to -0.005, I² = 7.0%). In addition, IF regimens (WMD: -0.029; 95% CI: -0.058, -0.000, I² = 17.9%) were more effective in reducing CRP levels than ERDs (WMD: -0.001 mg/dl; 95% CI: -0.037, 0.034, I² = 0.0%). Moreover, based on the treatment duration and types of the studies’ population, a greater reduction was observed in overweight and obese individuals (WMD: -0.03 mg/dl; 95% CI: -0.05, 0.01, I² = 42.1%), and in treatment duration ≥8 weeks (WMD: -0.03 mg/dl; 95% CI: -0.05, 0.01, I² = 0.0%) as well. However, IF and ERDs did not significantly reduced tumor necrosis factor alpha (TNF-α) (WMD: -0.158 pg/mL; p = 0.549, I² = 98.3) and interleukin-6 (IL-6) concentrations (WMD: -0.541 pg/mL; p = 0.080, I² = 94.7%).
Conclusions
This meta-analysis showed that IF regimens and ERDs may reduce CRP concentrations, particularly in overweight and obese subjects and through a considerable length of intervention (at least ≥2 months). However, both dietary models did not affect the concentrations of TNF-α and IL-6.
Background & aims.
Alternate-day fasting (ADF) is related to weight reduction, lowered risks of weight regain, and relative lean body mass preservation compared to continuous energy restriction. This meta-analysis aimed to assess the effects of ADF on obesity-related factors and cardiometabolic risk factors in adults.
Methods
Using PubMed, EMBASE, and Cochrane online databases, an electronic search was performed. Randomized controlled trials were investigated to evaluate ADF effects on body mass index (BMI), body weight (BW), waist circumference, body fat mass (FM), lean body mass, and cardiometabolic risk factors in adults aged ≥18 years. By utilizing a random-effects model, meta-analyses to assess weighted mean difference (WMD) with 95% confidence intervals (CIs) were performed for eight randomized controlled trials (total participants = 728).
Results
We observed significant effects of ADF for BMI (WMD −0.73 kg/m², 95% CI −1.13 to −0.34), FM (WMD −1.27 kg, 95% CI −2.09 to −0.46), and total cholesterol (WMD −8.14 mg/dL, 95% CI −14.59 to −1.69). Subgroup analyses indicated that significant intervention effects were observed for BMI, BW, FM, and total cholesterol when compared to the control, the participants were overweight, and the study duration was <6 months. ADF is effective in reducing waist circumference in adults aged ≥40 years with obesity. However, there was no difference between ADF and continuous energy restriction, time-restricted feeding, or control with regard to lean body mass.
Conclusions
Current evidence suggests that ADF effectively lowers BMI, BW, FM, and total cholesterol in adults with overweight within 6 months compared to the control.
The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.
Cellular senescence is a state of irreversible growth arrest characterized by hypertrophy and secretion of various bioactive molecules, a phenomenon defined the Senescence-Associated Secretory Phenotype (SASP). Senescent cells are implicated in a number of biological functions, from embryogenesis to aging. Significantly, excessive accumulation of senescent cells is associated to a decline of regenerative capacity and chronic inflammation. In accordance, the removal of senescent cells is sufficient to delay several pathologies and promote healthspan. Calorie restriction (CR) without malnutrition is currently the most effective non-genetic intervention to delay aging phenotypes. Recently, we have shown that CR can prevent accumulation of senescent cells in both mice and humans. Here, we summarize the current knowledge on the molecular and cellular events associated with CR, and define how these events can interfere with the induction of cellular senescence. We discuss the potential side effects of preventing senescence, and the possible alternative dietary interventions with potential senolytic properties.
Objectives:
The Nordic diet (ND) is regarded as a healthy dietary pattern that might beneficially affect systemic chronic inflammation; however, the results of published studies are conflicting. The present systematic review and meta-analysis aimed to summarize the published evidence by randomized controlled clinical trials with regard to the effect of the ND pattern on circulating inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α).
Methods:
PubMed, ISI Web of Science, Scopus, and Google Scholar were searched up to October 2017 to identify relevant studies. The risk of bias in the included studies was assessed using Cochrane's collaboration tool. The overall effects were calculated using the random effects model.
Results:
Seven studies were eligible to be included in the systematic review. All studies were conducted in Nordic countries. The meta-analysis of six eligible clinical trials included 613 adult participants and showed that adherence to the ND does not significantly affect circulating CRP levels (weighted mean difference [WMD]: -0.17 mg/L; 95% confidence interval [CI], -0.69 to 0.35; P = 0.529). The meta-analysis of three studies that reported on the effect on other inflammatory makers also failed to find any significant effect on TNF-α (WMD: 0.23 mg/L; 95% CI, -0.75 to 1.21; P = 0.645) and IL-6 (WMD: 0.13 mg/L, 95% CI, -0.29 to 0.56; P = 0.539) concentrations.
Conclusions:
Adherence to the ND pattern does not seem to affect circulating CRP, IL-6, and TNF-α levels. Clinical trials with longer follow-up periods and including participants in other regions are highly recommended.
Cardiovascular (CV) disease (CVD) is the leading global cause of mortality, being responsible for 46% of non-communicable disease deaths. It has been estimated that about 85.6 million Americans are living with some form of CVD, which continues to rise. Healthy lifestyle choices may reduce the risk of myocardial infarction by >80%, with nutrition playing a key role. Vegetarian dietary patterns reduce CVD mortality and the risk of coronary heart disease (CHD) by 40%. Plant-based diets are the only dietary pattern to have shown reversal of CHD. Additionally, evidence suggests benefits of vegetarian dietary patterns in both the prevention and the treatment of heart failure and cerebrovascular disease. Plant-based diets are associated with lower blood pressure, lower blood lipids, and reduced platelet aggregation than non-vegetarian diets and are beneficial in weight management, reduce the risk of developing metabolic syndrome, and type 2 diabetes. They have also been shown an effective treatment method in diabetes management. Well planned vegetarian diets provide benefits in preventing and reversing atherosclerosis and in decreasing CVD risk factors and should be promoted through dietary guidelines and recommendations.
Background:
Endothelial dysfunction is one of the mechanisms linking diet and the risk of cardiovascular disease.
Objective:
We evaluated the hypothesis that dietary patterns (summary measures of food consumption) are directly associated with markers of inflammation and endothelial dysfunction, particularly C-reactive protein (CRP), interleukin 6, E-selectin, soluble intercellular adhesion molecule 1 (sICAM-1), and soluble vascular cell adhesion molecule 1 (sVCAM-1).
Design:
We conducted a cross-sectional study of 732 women from the Nurses' Health Study I cohort who were 43-69 y of age and free of cardiovascular disease, cancer, and diabetes mellitus at the time of blood drawing in 1990. Dietary intake was documented by using a validated food-frequency questionnaire in 1986 and 1990. Dietary patterns were generated by using factor analysis.
Results:
A prudent pattern was characterized by higher intakes of fruit, vegetables, legumes, fish, poultry, and whole grains, and a Western pattern was characterized by higher intakes of red and processed meats, sweets, desserts, French fries, and refined grains. The prudent pattern was inversely associated with plasma concentrations of CRP (P = 0.02) and E-selectin (P = 0.001) after adjustment for age, body mass index (BMI), physical activity, smoking status, and alcohol consumption. The Western pattern showed a positive relation with CRP (P < 0.001), interleukin 6 (P = 0.006), E-selectin (P < 0.001), sICAM-1 (P < 0.001), and sVCAM-1 (P = 0.008) after adjustment for all confounders except BMI; with further adjustment for BMI, the coefficients remained significant for CRP (P = 0.02), E-selectin (P < 0.001), sICAM-1 (P = 0.002), and sVCAM-1 (P = 0.02).
Conclusion:
Because endothelial dysfunction is an early step in the development of atherosclerosis, this study suggests a mechanism for the role of dietary patterns in the pathogenesis of cardiovascular disease.
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 (four in non-Mediterranean countries) demonstrated non-significant reductions and two trials conducted in Spain demonstrated significant reductions in C-reactive protein (CRP) with a Mediterranean-type diet. Random effects meta-analysis of four controlled trials detected a non-significant difference in final mean value of CRP with Mediterranean-type diet versus low fat diet. Despite promising findings from observational studies, this review demonstrated mostly non-significant 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.
Objective
Vegetarian diets contain various anti-inflammatory components. We aimed to investigate the effects of vegetarianism on inflammatory biomarkers when compared with omnivores.
Design
Systematic review and meta-analysis.
Setting
Literature search was conducted in Science Direct, Proquest, MEDLINE and Google Scholar up to June 2016. Summary estimates and corresponding 95 % CI were derived via the DerSimonian and Laird method using random effects, subgroup analyses were run to find the source of heterogeneity and a fixed-effect model examined between-subgroup heterogeneity.
Subjects
Studies were included if they evaluated effects of any type of vegetarianism compared with omnivores on circulating levels of inflammatory biomarkers. No restriction was made in terms of language or the date of study publications.
Results
Eighteen articles were included. Pooled effect size showed no difference in high-sensitivity C-reactive protein (hs-CRP) levels in vegetarians v. omnivores (Hedges’ g=−0·15; 95 % CI −0·35, 0·05), with high heterogeneity (I 2=75·6 %, Pv. omnivores (Hedges’ g=−0·29; 95 % CI −0·59, 0·01), with moderate heterogeneity (I 2=68·9 %, PI 2=0·0 %, P=0·60).
Conclusions
The meta-analysis provides evidence that vegetarianism is associated with lower serum concentrations of hs-CRP when individuals follow a vegetarian diet for at least 2 years. Further research is necessary to draw appropriate conclusions regarding potential associations between vegetarianism and IL-6 levels. A vegetarian diet might be a useful approach to manage inflammaging in the long term.
Background—Current findings on associations between whole grain (WG) intake and mortality are inconsistent and have not been summarized by meta-analysis.
Methods and Results—We searched for prospective cohort studies reporting associations between WG intake and mortality from all causes, cardiovascular disease (CVD), and cancer through February 2016 in Medline, Embase, and clinicaltrials.gov, and we further included unpublished results from National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999 to 2004. Fourteen studies were eligible for analysis, which included 786 076 participants, 97 867 total deaths, 23 957 CVD deaths, and 37 492 cancer deaths. Pooled relative risks comparing extreme WG categories (high versus low) were 0.84 (95% confidence interval [CI], 0.80–0.88; P<0.001; I²=74%; Pheterogeneity<0.001) for total mortality, 0.82 (95% CI, 0.79–0.85; P<0.001; I²=0%; Pheterogeneity=0.53) for CVD mortality, and 0.88 (95% CI, 0.83–0.94; P<0.001; I²=54%; Pheterogeneity=0.02) for cancer mortality. Intakes of WG ingredients in dry weight were estimated among studies reporting relative risks for ≥3 quantitative WG categories, and they were <50 g/d among most study populations. The 2-stage dose-response random-effects meta-analysis showed monotonic associations between WG intake and mortality (Pnonlinearity>0.05). For each 16-g/d increase in WG (≈1 serving per d), relative risks of total, CVD, and cancer mortality were 0.93 (95% CI, 0.92–0.94; P<0.001), 0.91 (95% CI, 0.90–0.93; P<0.001), and 0.95 (95% CI, 0.94–0.96; P<0.001), respectively.
Conclusions—Our meta-analysis demonstrated inverse associations of WG intake with total and cause-specific mortality, and findings were particularly strong and robust for CVD mortality. These findings further support current Dietary Guidelines for Americans, which recommends at least 3 servings per day of WG intake.
Background: Chronic low-grade inflammation has been associated with insulin resistance, diabetes, atherosclerosis, obesity and Metabolic Syndrome (MetS). A pro-inflammatory environment contributes to several metabolic disturbances and possibly the development of MetS. Dietary approaches have defined impact on immune function and putative anti-inflammatory effects.
Objective: To assess the effects of different dietary approaches on markers of inflammation among patients with metabolic syndrome. Further effects on weight loss and fasting insulin were analysed.
Design: MEDLINE/Pubmed, Scopus and the Cochrane Library were screened through September 2014 for randomized controlled trials (RCTs) on different dietary approaches for participants with metabolic syndrome as defined by NCEP ATP III. Primary outcome were markers of immune system. Secondary outcome was body weight and fasting insulin. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated.
Results: 13 RCTs with a total of 2017 patients were included. Low-fat diets (29±2 % energy from fats) decreased C- reactive protein when compared to control diets (SMD=-0.98, 95% CI -1.6, -0.35, p= 0.002). Low- carbohydrate diets (SMD=-0.33, 95% CI -0.63, -0.03, p=0.004, 23±10% energy from carbohydrates) and multimodal interventions (SMD=-1.02, 95% CI-1.97, -0.07, p=0.04) were able to induce significant weight loss. Low carb diets were able to decrease insulin (SMD: -0.33; 95% CI -0.63, -0.03; p=0.03).
Conclusion: Low-fat diets are able to reduce CRP, however this effect is also dependent from weight loss. Further low-carb diets have beneficial effects on insulin and body weight. Dietary approaches should mainly try to reduce macronutrients and enrich functional food components such as vitamins, flavonoids and unsaturated fatty acids. People with metabolic syndrome will benefit most by combining weight loss and anti-inflammatory nutrients.
Objective
To determine the effect of plant-based diets on weight loss.
Research Methods and Procedures: Participants were enrolled in a six-month, five-arm, randomized controlled trial in 2013 in South Carolina. Participants attended weekly group meetings, with the exception of the omnivorous group, which served as the control and attended monthly meetings augmented with weekly e-mail lessons. All groups attended monthly meetings for the last four months of the study. Diets did not emphasize caloric restriction.
Results
Overweight adults (body mass index: 25.0-49.9 kg/m2; age: 18-65 years, 19% nonwhite, and 27% male) were randomized to a diet emphasizing a low-fat and low-glycemic index diet: vegan (n=12), vegetarian (n=13), pesco-vegetarian (n=13), semi-vegetarian (n=13), or omnivorous (n=12). Fifty (79%) participants completed the study. In intention-to-treat analysis, the linear trend for weight loss across the five groups was significant at both two (P<0.01) and six months (P<0.01). At six months, the weight loss in the vegan group (-7.5 ± 4.5%) was significantly different from the omnivorous (-3.1 ± 3.6%, P=0.03), semi-vegetarian (-3.2 ± 3.8%, P=0.03), and pesco-vegetarian (-3.2 ± 3.4%, P=0.03) groups. Vegan participants decreased their fat and saturated fat more than did the pesco-vegetarian, semi-vegetarian, and omnivorous groups at both two and six months (P<0.05).
Conclusions
Vegan diets may result in greater weight loss than more modest recommendations.
Background:
In this substudy of the effect of dietary nitrate on blood pressure, endothelial function, and insulin sensitivity in type 2 diabetes, we report the development of a novel nitrate depleted beetroot juice for use clinical trials and determine if dietary nitrate supplementation improved cognitive function in patients with type 2 diabetes mellitus.
Methods:
Beetroot juice was treated with the anion exchange resin Purolite A520e. UV-vis-spectrophotometry, and a blind taste test were performed along with determination of sugar content, measurement of ascorbate and dehydroascorbate, the ionic composition of juice and Proton NMR. Subsequently, 27 patients, age 67.2±4.9 years, (18 male) were recruited for a double blind, randomised, placebo-controlled crossover trial. Participants were randomised to begin in either order beetroot juice (nitrate content 7.5 mmol per 250 ml) or placebo (nitrate depleted beetroot juice nitrate content 0.002 mmol per 250 ml). At the end of each 2 week supplementation period cognitive function was assessed using E-prime, E-Studio software with 5 separate tests being performed. The tests utilised in the present study have been adapted from the Cambridge Neuropsychological Test Automated Battery (CANTAB).
Results:
The differences in the UV-vis spectra were comparable to the natural variation found in differing cultivars. There were no discernable differences in taste, sugar content, or Proton NMR. Ascorbate and dehydroascorbate were undetectable in either juice. After 2 weeks of beetroot juice simple reaction time was significantly quicker in the active arm at 327±40 ms versus 341.8±52.7 ms in the placebo arm, mean difference 13.9±25.6 ms (95% CI 3.8-24.0 ms), p=0.009. No other measures of cognitive function differed between treatment arms.
Conclusion:
We have developed an effective placebo beetroot juice for use in trials of supplementation of dietary nitrate. Two weeks supplementation of the diet with 7.5 mmol of nitrate per day caused a significant improvement in simple reaction time in individuals with T2DM.
Background
High adherence to a Mediterranean diet (MD) is associated with reduced all-cause and cardiovascular mortality risk. To our knowledge, there is no systematic review and meta-analysis of randomized controlled trials that has compared the effects of an MD on outcomes of endothelial function and inflammation.
Methods
Literature search was performed using the electronic databases MEDLINE, EMBASE, and the Cochrane Trial Register. Inclusion criteria were: randomized controlled trials, 19+ years of age, and minimum intervention period of 12 weeks. Study specific weighted mean differences (WMD) were pooled using a random effect model.
Results
17 trials including 2300 subjects met the objectives. MD regimens resulted in a significantly more pronounced increase in flow mediated dilatation [WMD: 1.86%, 95% CI 0.23 to 3.48, p = 0.02; I2 = 43%], and adiponectin [WMD: 1.69 μg/ml, 95% CI 0.27 to 3.11, p = 0.02; I2 = 78%], while high-sensitive C reactive protein [WMD: -0.98 mg/l, 95% CI -1.48 to -0.49, p < 0.0001; I2 = 91%], interleukin-6 [WMD: -0.42 pg/ml, 95% CI -0.73 to -0.11, p = 0.008; I2 = 81%], and intracellular adhesion molecule-1 [WMD: -23.73 ng/ml, 95% CI -41.24 to -6.22 p = 0.008; I2=34%] turned out to be significantly more decreased.
Conclusion
The results of the present meta-analysis provide evidence that an MD decreases inflammation and improves endothelial function.
Background: Both C-reactive protein and low-density lipoprotein (LDL) cholesterol levels are elevated in persons at risk for cardiovascular events. However, population-based data directly comparing these two biologic markers are not available. Methods: C-reactive protein and LDL cholesterol were measured at base line in 27,939 apparently healthy American women, who were then followed for a mean of eight years for the occurrence of myocardial infarction, ischemic stroke, coronary revascularization, or death from cardiovascular causes. We assessed the value of these two measurements in predicting the risk of cardiovascular events in the study population. Results: Although C-reactive protein and LDL cholesterol were minimally correlated (r=0.08), base-line levels of each had a strong linear relation with the incidence of cardiovascular events. After adjustment for age, smoking status, the presence or absence of diabetes mellitus, categorical levels of blood pressure, and use or nonuse of hormone-replacement therapy, the relative risks of first cardiovascular events according to increasing quartiles of C-reactive protein, as compared with the women in the lowest quintile, were 1.4, 1.6, 2.0, and 2.3 (P<0.001), whereas the corresponding relative risks in increasing quintiles of LDL cholesterol, as compared with the lowest, were 0.9, 1.1, 1.3, and 1.5 (P<0.001). Similar effects were observed in separate analyses of each component of the composite end point and among users and nonusers of hormone-replacement therapy. Overall, 77 percent of all events occurred among women with LDL cholesterol levels below 160 mg per deciliter (4.14 mmol per liter), and 46 percent occurred among those with LDL cholesterol levels below 130 mg per deciliter (3.36 mmol per liter). By contrast, because C-reactive protein and LDL cholesterol measurements tended to identify different high-risk groups, screening for both biologic markers provided better prognostic information than screening for either alone. Independent effects were also observed for C-reactive protein in analyses adjusted for all components of the Framingham risk score. Conclusions: These data suggest that the C-reactive protein level is a stronger predictor of cardiovascular events than the LDL cholesterol level and that it adds prognostic information to that conveyed by the Framingham risk score.