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The British Journal of Nutrition Nov 2023Vegan and vegetarian diets are widely supported and adopted, but individuals following such diets remain at greater risk of iodine deficiency. This systematic review and... (Meta-Analysis)
Meta-Analysis Review
Vegan and vegetarian diets are widely supported and adopted, but individuals following such diets remain at greater risk of iodine deficiency. This systematic review and meta-analysis was conducted to assess the iodine intake and status in adults following a vegan or vegetarian diet in the modern day. A systematic review and quality assessment were conducted from October 2020 to December 2022 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidance. Studies were identified in Ovid MEDLINE, Web of Science, PubMed, and Scopus. Eleven articles were eligible for review containing 4421 adults (aged ≥ 18 years). Vegan groups had the lowest median urinary iodine concentration (mUIC) (12·2/l). None of the dietary groups had mUIC within the optimal range for iodine status (100-200 µg/l) (WHO). Vegan diets had the poorest iodine intake (17·3 µg/d) and were strongly associated with lower iodine intake ( = < 0·001) compared with omnivorous diets. Lower intake in vegan diets was influenced by sex ( = 0·007), the presence of voluntary or absence of Universal Salt Iodisation (USI) programmes ( = 0·01 & = < 0·001), and living in a country with adequate iodine nutrition ( = < 0·001). Vegetarians and particularly vegans living in countries with no current USI programme continue to have increased risk of low iodine status, iodine deficiency and inadequate iodine intake. Further research into the usefulness of mandatory fortification of vegan appropriate foods is required.
Topics: Adult; Humans; Diet, Vegan; Vegans; Iodine; Diet, Vegetarian; Nutritional Status; Vegetarians
PubMed: 36912094
DOI: 10.1017/S000711452300051X -
Neurogastroenterology and Motility Jan 2024Numerous individual and environmental factors including diet may play an important role in the pathophysiology of irritable bowel syndrome (IBS). It is unclear to what... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Numerous individual and environmental factors including diet may play an important role in the pathophysiology of irritable bowel syndrome (IBS). It is unclear to what degree dietary intake is affected in individuals with IBS. We aimed to perform a systematic review and meta-analysis to summarize dietary intake of adults with IBS and to compare dietary intake between adults with IBS and non-IBS controls.
METHODS
Ovid MEDLINE, Embase, Cochrane, CINAHL, and Scopus were searched through February 2023 for clinical trials and observational studies measuring usual diet in adults with IBS. Pooled weighted averages were estimated for total energy, macronutrient, and micronutrient data. Mean differences (MD) in nutrient intake were estimated for adults with IBS versus non-IBS controls using a random effects model. Heterogeneity was assessed by the inconsistency index (I2).
KEY RESULTS
Sixty-three full-text articles were included in the review of which 29 studies included both IBS and control subjects. Nutrients not meeting the recommended intake level for any dietary reference values in the IBS population were fiber and vitamin D. Meta-regression by female proportion was positively correlated with total fat intake and negatively correlated with carbohydrate intake. Comparisons between participants with IBS and controls showed significantly lower fiber intake in participants with IBS with high heterogeneity (MD: -1.8; 95% CI: -3.0, -0.6; I2 = 85%).
CONCLUSIONS AND INFERENCES
This review suggests that fiber and vitamin D intake is suboptimal in IBS; however, overall dietary intake does not appear to be comprised. Causes and consequences of reduced fiber in IBS deserve further study. Results of this systematic review and meta-analysis suggest that fiber and vitamin D intake is suboptimal in IBS. However, overall intake of other macro- and micronutrients does not appear to be compromised. Causes and consequences of reduced fiber and Vitamin D intake in IBS deserve further study.
Topics: Adult; Humans; Female; Irritable Bowel Syndrome; Diet; Eating; Energy Intake; Vitamin D
PubMed: 37897138
DOI: 10.1111/nmo.14698 -
Alimentary Pharmacology & Therapeutics Jan 2024Dietary approaches are recommended for the management of chronic constipation. Until now, there has been no systematic review and meta-analysis on foods, drinks and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Dietary approaches are recommended for the management of chronic constipation. Until now, there has been no systematic review and meta-analysis on foods, drinks and diets in constipation.
AIMS
To investigate the effect of foods, drinks and diets on response to treatment, stool output, gut transit time, symptoms, quality of life, adverse events and compliance in adults with chronic constipation via a systematic review and meta-analysis.
METHODS
Studies were identified using electronic databases (12th July 2023). Intervention trials (randomised controlled trials [RCTs], non-randomised, uncontrolled) were included. Risk of bias was assessed using Cochrane 2.0 (RCTs) or JBI Critical Appraisal (uncontrolled trials). Data from RCTs only were synthesised using risk ratios (RRs), mean differences (MDs), standardised mean differences (95% CI) using random-effects.
RESULTS
We included 23 studies (17 RCTs, 6 uncontrolled; 1714 participants): kiwifruit (n = 7), high-mineral water (n = 4), prunes (n = 2), rye bread (n = 2), mango, fig, cereal, oat bran, yoghurt, water supplementation, prune juice, high-fibre diet, no-fibre diet (n = 1). Fruits resulted in higher stool frequency than psyllium (MD: +0.36 bowel movements [BM]/week, [0.25-0.48], n = 232), kiwifruits in particular (MD: +0.36 BM/week, [0.24-0.48], n = 192); there was no difference for prunes compared with psyllium. Rye bread resulted in higher stool frequency than white bread (MD: +0.43 BM/week, [0.03-0.83], n = 48). High-mineral water resulted in higher response to treatment than low-mineral water (RR: 1.47, [1.20-1.81], n = 539).
CONCLUSIONS
Fruits and rye bread may improve certain constipation-related outcomes. There is a scarcity of evidence on foods, drinks and diets in constipation and further RCTs are needed.
Topics: Adult; Humans; Psyllium; Constipation; Dietary Fiber; Diet; Mineral Waters
PubMed: 37905980
DOI: 10.1111/apt.17782 -
Dietary Interventions in Ulcerative Colitis: A Systematic Review of the Evidence with Meta-Analysis.Nutrients Sep 2023(1) Background: Ulcerative colitis (UC) is a chronic colon inflammation caused by genetic and environmental factors, including diet. This systematic review and... (Meta-Analysis)
Meta-Analysis Review
(1) Background: Ulcerative colitis (UC) is a chronic colon inflammation caused by genetic and environmental factors, including diet. This systematic review and meta-analysis aims to assess the impact of diet on UC management in children and adults (2) Methods: A comprehensive search across databases yielded relevant studies, and risk of bias in randomized controlled trials (RCTs) was assessed using the Cochrane Risk of Bias tool. This study was conducted in conformity to the 2020 PRISMA guidelines. The certainty of evidence for outcomes was evaluated using GRADE methodology. Meta-analysis was performed using Review Manager software version 5.4. (3) Results: Fourteen RCTs were included, results indicated higher clinical response, remission, and endoscopic remission rates in diet-treated groups. Carrageenan-free, anti-inflammatory, and cow milk protein elimination diets showed no significant advantages in maintaining clinical remission. However, a study involving fermented cow milk with bifidobacterial demonstrated favorable outcomes. Overall, pooled analysis leaned in favor of dietary intervention for sustaining clinical remission; (4) Conclusions: The relationship between diet and UC is an evolving terrain that demands deeper exploration. This systematic review and meta-analysis highlight the evolving relationship between diet and UC, necessitating further exploration. While understanding grows, adopting personalized dietary approaches could alleviate symptoms, and support a more positive disease trajectory.
Topics: Adult; Child; Humans; Colitis, Ulcerative; Remission Induction; Anti-Inflammatory Agents, Non-Steroidal; Inflammation
PubMed: 37836478
DOI: 10.3390/nu15194194 -
Public Health Nutrition Dec 2023This systematic review aimed to investigate the association between dietary inflammatory potential and liver cancer to provide evidence regarding scientific dietary... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This systematic review aimed to investigate the association between dietary inflammatory potential and liver cancer to provide evidence regarding scientific dietary health education.
DESIGN
Systematic review and meta-analysis.
SETTING
A comprehensive literature review was conducted to identify case-control or cohort studies that involved dietary inflammation index (DII)/empirical dietary inflammation pattern (EDIP) and liver cancer in PubMed, EMBASE, Cochrane, and Web of Science databases. Using a combination of DII/EDIP and liver cancer as the search terms, the associations between DII/EDIP and liver cancer were then assessed.
PARTICIPANTS
Three case-control studies and two cohort studies were brought into the meta-analysis, with 225 713 enrolled participants.
RESULTS
Meta-analysis of categorical variables showed that DII/EDIP in the highest category increased the risk of liver cancer compared to DII/EDIP in the lowest category (relative risk (RR) = 2·35; 95 % CI 1·77, 3·13; = 0·000) and with low heterogeneity across studies (I = 40·8 %, = 0·119). Meta-analysis of continuous variables showed that significant positive association between liver cancer and DII/EDIP scores (RR = 1·24; 95 % CI 1·09, 1·40; = 0·001), and no heterogeneity (I² = 0·0 %, = 0·471). Stratified according to the study design, there was a significant positive association between liver cancer and DII/EDIP scores in both cohort studies (RR = 2·16; 95 % CI 1·51, 3·07; = 0·000) and case-control studies (RR = 2·75; 95 % CI 1·71, 4·41; = 0·000).
CONCLUSION
The higher the DII/EDIP score, the higher the risk of liver cancer. This finding may have prominent implications for the general population.
Topics: Humans; Risk Factors; Diet; Inflammation; Liver Neoplasms; Dietary Patterns
PubMed: 37990536
DOI: 10.1017/S1368980023002574 -
Nutrients Sep 2023Available results on the association between the Mediterranean diet (MD) and gastric cancer (GC) incidence are controversial. The present study aimed to determine the... (Meta-Analysis)
Meta-Analysis Review
Available results on the association between the Mediterranean diet (MD) and gastric cancer (GC) incidence are controversial. The present study aimed to determine the correlation between different subtypes of GC and MD adherence. This meta-analysis was registered on PROSPERO (CRD42021284432). We searched Embase, PubMed, Cochrane Library, and Web of Science from inception through 22 April 2023 to retrieve relevant studies. A random-effects model was used to pool odds ratios (ORs) with 95% confidence intervals (CIs). Eleven studies were included in the meta-analysis. Pooled analyses revealed that adherence to the MD was inversely associated with GC risk (OR, 0.43; 95% CI, 0.29 to 0.63; OR, 0.84; 95% CI, 0.77 to 0.92). Higher MD adherence was significantly associated with a reduced GC risk in male (OR, 0.78; 95% CI, 0.65 to 0.93; OR, 0.81; 95% CI, 0.65 to 1.01), but not in female (OR, 0.83; 95% CI, 0.68 to 1.01; OR, 1.04; 95% CI, 0.82 to 1.31). Furthermore, adherence to the MD possibly decreased the risk of gastric cardia adenocarcinoma (GCA) (OR, 0.64; 95% CI, 0.49 to 0.83; OR, 0.88; 95% CI, 0.76 to 1.02) and gastric non-cardia adenocarcinoma (GNCA) (OR, 0.68; 95% CI, 0.59 to 0.79; OR, 0.85; 95% CI, 0.78 to 0.94). Our results indicate that adherence to the MD reduces the risk of GC and its subtypes.
Topics: Female; Male; Humans; Stomach Neoplasms; Diet, Mediterranean; Adenocarcinoma; Odds Ratio; PubMed
PubMed: 37686858
DOI: 10.3390/nu15173826 -
Aging Clinical and Experimental Research Mar 2024Dementia affects 5-8% of the population aged over 65 years (~50 million worldwide). Several factors are associated with increased risk, including diet. The... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Dementia affects 5-8% of the population aged over 65 years (~50 million worldwide). Several factors are associated with increased risk, including diet. The Mediterranean diet (MedDiet) has shown potential protective effects against several chronic diseases.
AIMS
This systematic review with meta-analysis aim was to assess the association between adherence to the MedDiet and the risk of dementia in the elderly.
METHODS
PRISMA-2020 guidelines were followed. PubMed/MEDLINE and Scopus were searched on 17 July 2023. The Newcastle-Ottawa Scale tool was used to assess the risk of bias. The protocol was pre-registered in PROSPERO (registration number: CRD 42023444368). Heterogeneity was assessed using the I test. Publication bias was assessed by visual inspection of the funnel plot and by Egger's regression asymmetry test. The final effect size was reported as OR or HR, depending on the study design of the included studies.
RESULTS
Out of 682 records, 21 were included in the analysis. The pooled OR was 0.89 (95% CI = 0.84-0.94) based on 65,955 participants (I = 69.94). When only cohort studies were included, HR was 0.84 (95% CI = 0.76-0.94) based on 55,205 participants (I = 89.70). When only Alzheimer Disease was considered OR was 0.73 (95% CI = 0.62-0.85) based on 38,292 participants (I = 63.85).
DISCUSSION
Despite the relatively low risk reduction associated with higher adherence to MedDiet among elderly, it should be considered that this population is the most affected.
CONCLUSIONS
Adherence to MedDiet could be an effective non-pharmacological measure to reduce the burden of dementia, even among elderly.
Topics: Aged; Humans; Alzheimer Disease; Diet, Mediterranean; Cohort Studies; Risk; Research Design
PubMed: 38519775
DOI: 10.1007/s40520-024-02718-6 -
Nutrition & Dietetics: the Journal of... Feb 2024To evaluate relationships between diet quality and cardiovascular outcomes. (Meta-Analysis)
Meta-Analysis Review
AIMS
To evaluate relationships between diet quality and cardiovascular outcomes.
METHODS
Six databases were searched for studies published between January 2007 and October 2021. Eligible studies included cohort studies that assessed the relationship between a priori diet quality and cardiovascular disease mortality and morbidity in adults. The Academy of Nutrition and Dietetics Checklist was used to assess the risk of bias. Study characteristics and outcomes were extracted from eligible studies using standardised processes. Data were summarised using risk ratios for cardiovascular disease incidence and mortality with difference compared for highest versus lowest diet quality synthesised in meta-analyses using a random effects model.
RESULTS
Of the 4780 studies identified, 159 studies (n = 6 272 676 adults) were included. Meta-analyses identified a significantly lower cardiovascular disease incidence (n = 42 studies, relative risk 0.83, 95% CI 0.82-0.84, p < 0.001) and mortality risk (n = 49 studies, relative risk 0.83, 95% CI 0.82-0.84, p < 0.001) among those with highest versus lowest diet quality. In sensitivity analyses of a high number of pooled studies (≥13 studies) the Mediterranean style diet patterns and adherence to the heart healthy diet guidelines were significantly associated with a risk reduction of 15% and 14% for cardiovascular disease incidence and 17% and 20% for cardiovascular disease mortality respectively (p < 0.05).
CONCLUSIONS
Higher diet quality is associated with lower incidence and risk of mortality for cardiovascular disease however, significant study heterogeneity was identified for these relationships.
Topics: Adult; Humans; Cardiovascular Diseases; Cohort Studies; Diet, Mediterranean; Diet, Healthy
PubMed: 38129766
DOI: 10.1111/1747-0080.12860 -
Nutrients Jan 2024The prevalence of sleep disorders, characterized by issues with quality, timing, and sleep duration is increasing globally. Among modifiable risk factors, diet quality... (Review)
Review
The prevalence of sleep disorders, characterized by issues with quality, timing, and sleep duration is increasing globally. Among modifiable risk factors, diet quality has been suggested to influence sleep features. The Mediterranean diet is considered a landmark dietary pattern in terms of quality and effects on human health. However, dietary habits characterized by this cultural heritage should also be considered in the context of overall lifestyle behaviors, including sleep habits. This study aimed to systematically revise the literature relating to adherence to the Mediterranean diet and sleep features in observational studies. The systematic review comprised 23 reports describing the relation between adherence to the Mediterranean diet and different sleep features, including sleep quality, sleep duration, daytime sleepiness, and insomnia symptoms. The majority of the included studies were conducted in the Mediterranean basin and reported a significant association between a higher adherence to the Mediterranean diet and a lower likelihood of having poor sleep quality, inadequate sleep duration, excessive daytime sleepiness or symptoms of insomnia. Interestingly, additional studies conducted outside the Mediterranean basin showed a relationship between the adoption of a Mediterranean-type diet and sleep quality, suggesting that biological mechanisms sustaining such an association may exist. In conclusion, current evidence suggests a relationship between adhering to the Mediterranean diet and overall sleep quality and different sleep parameters. The plausible bidirectional association should be further investigated to understand whether the promotion of a healthy diet could be used as a tool to improve sleep quality.
Topics: Humans; Diet, Mediterranean; Sleep Initiation and Maintenance Disorders; Sleep; Sleep Quality; Risk Factors; Observational Studies as Topic
PubMed: 38257175
DOI: 10.3390/nu16020282 -
Journal of Gastrointestinal and Liver... Sep 2023Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Studies evaluated the effect of several diets on inflammatory markers...
BACKGROUND AND AIMS
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract. Studies evaluated the effect of several diets on inflammatory markers in IBD patients. Nevertheless, the results have been inconsistent. Therefore, we conducted this review to evaluate the effectiveness of dietary interventions on inflammatory markers in IBD.
METHODS
A comprehensive electronic literature search strategy using the PubMed, Embase, and Scopus was conducted in March 2023 and evaluated inflammatory markers included C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and fecal calprotectin (FC), as well as disease severity scores. We included full-text articles that met our inclusion and exclusion criteria. To evaluate the included studies, we used the NHLBI quality evaluation tools.
RESULTS
A total of 16 studies were included in our qualitative synthesis. Elemental and polymeric diets showed similar efficacy in reducing Crohn's disease activity index (CDAI) and CRP levels. On the other hand, most studies evaluating the effects of omega 3 fatty acids reported no significant improvement. Moreover, protein supplementation was not seen to improve ESR or CRP levels. Except for improvements in FC levels with IgG4-guided exclusion diet in CD patients with elevated CDAI levels, restrictive diets were successful in controlling functional abdominal symptoms but did not appear to have an impact on inflammation in most studies. Furthermore, disease severity scores, CRP, ESR, and FC levels did not significantly change when eating a high-fiber, low-refined-carb, low-fat diet.
CONCLUSIONS
Diet plays a vital role in managing IBD by impacting the inflammatory response. Among the interventions studied, enteral nutrition showed the most promising results, improving patients' inflammatory status. Restrictive diets effectively managed symptoms and clinical remission but had limited impact on inflammatory markers. Supplementing the diet with fatty acids, omega 3, or proteins did not definitively improve patients' condition or inflammation.
PubMed: 37494554
DOI: 10.15403/jgld-5090