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Association between antibiotics and gut microbiome dysbiosis in children: systematic review and meta-analysis.
McDonnell, L, Gilkes, A, Ashworth, M, Rowland, V, Harries, TH, Armstrong, D, White, P
Gut microbes. 2021;13(1):1-18
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The gut microbiome and immune system are intricately connected and recent studies have demonstrated a link between antibiotic exposure and gut microbiome alteration in neonates. Antibiotics in childhood may be linked to a variety of diseases and although the mechanism of association for diseases has not been fully explored, the underlying cause could be linked to dysbiosis in the gut microbiome. The aim of this systematic review was to examine the association between paediatric antibiotic exposure and gut microbiome disruption. Among the existing literature, 12 studies were included and the results showed a significant reduction in both diversity and richness of the gut microbiome in children aged 0-18 following antibiotic exposure. Based on these findings, the authors conclude antibiotics appear to disrupt the normal maturation of the microbiome and alter the healthy balance of bacteria. They recommend healthcare providers consider the potential damage to the gut microbiome when prescribing antibiotics for children.
Abstract
Antibiotics in childhood have been linked with diseases including asthma, juvenile arthritis, type 1 diabetes, Crohn's disease and mental illness. The underlying mechanisms are thought related to dysbiosis of the gut microbiome. We conducted a systematic review of the association between antibiotics and disruption of the pediatric gut microbiome. Searches used MEDLINE, EMBASE and Web of Science. Eligible studies: association between antibiotics and gut microbiome dysbiosis; children 0-18 years; molecular techniques of assessment; outcomes of microbiome richness, diversity or composition. Quality assessed by Newcastle-Ottawa Scale or Cochrane Risk of Bias Tool. Meta-analysis where possible. A total of 4,668 publications identified: 12 in final analysis (5 randomized controlled trials (RCTs), 5 cohort studies, 2 cross-sectional studies). Microbiome richness was measured in 3 studies, species diversity in 6, and species composition in 10. Quality of evidence was good or fair. 5 studies found a significant reduction in diversity and 3 a significant reduction in richness. Macrolide exposure was associated with reduced richness for twice as long as penicillin. Significant reductions were seen in Bifidobacteria (5 studies) and Lactobacillus (2 studies), and significant increases in Proteobacteria such as E. coli (4 studies). A meta-analysis of RCTs of the effect of macrolide (azithromycin) exposure on the gut microbiome found a significant reduction in alpha-diversity (Shannon index: mean difference -0.86 (95% CI -1.59, -0.13). Antibiotic exposure was associated with reduced microbiome diversity and richness, and with changes in bacterial abundance. The potential for dysbiosis in the microbiome should be taken into account when prescribing antibiotics for children.Systematic review registration number: CRD42018094188.
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Effect of Omega-3 Dosage on Cardiovascular Outcomes: An Updated Meta-Analysis and Meta-Regression of Interventional Trials.
Bernasconi, AA, Wiest, MM, Lavie, CJ, Milani, RV, Laukkanen, JA
Mayo Clinic proceedings. 2021;96(2):304-313
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There is mixed evidence to support the use of omega-3 fatty acids for the prevention and treatment of cardiovascular disease. Animal studies have shown promising results, but randomised control trials are inconsistent, possibly due to differing doses used, or differences in the subject’s omega-3 levels at the start of the trial. This meta-analysis of 40 studies with over 135,000 subjects aimed to determine whether omega-3 supplementation reduces heart disease risk and whether dosage has a role. The results showed that omega-3 supplementation reduced the risk of heart attacks, death from heart attacks and deaths due to heart disease, and the higher the dose, the greater the protection. The majority of studies were on individuals who had already had a heart attack or who had suffered from a related condition. It was concluded that supplementation with omega-3 is effective in preventing heart disease and heart attacks and the protective effect increases with dosage. This study could be used by healthcare professionals to prevent further heart disease and heart attacks in individuals who have already suffered from one of these conditions.
Abstract
OBJECTIVES To quantify the effect of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on cardiovascular disease (CVD) prevention and the effect of dosage. METHODS This study is designed as a random effects meta-analysis and meta-regression of randomized control trials with EPA/DHA supplementation. This is an update and expanded analysis of a previously published meta-analysis which covers all randomized control trials with EPA/DHA interventions and cardiovascular outcomes published before August 2019. The outcomes included are myocardial infarction (MI), coronary heart disease (CHD) events, CVD events (a composite of MI, angina, stroke, heart failure, peripheral arterial disease, sudden death, and non-scheduled cardiovascular surgical interventions), CHD mortality and fatal MI. The strength of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation framework. RESULTS A total of 40 studies with a combined 135,267 participants were included. Supplementation was associated with reduced risk of MI (relative risk [RR], 0.87; 95% CI, 0.80 to 0.96), high certainty number needed to treat (NNT) of 272; CHD events (RR, 0.90; 95% CI, 0.84 to 0.97), high certainty NNT of 192; fatal MI (RR, 0.65; 95% CI, 0.46 to 0.91]), moderate certainty NNT = 128; and CHD mortality (RR, 0.91; 95% CI, 0.85 to 0.98), low certainty NNT = 431, but not CVD events (RR, 0.95; 95% CI, 0.90 to 1.00). The effect is dose dependent for CVD events and MI. CONCLUSION Cardiovascular disease remains the leading cause of death worldwide. Supplementation with EPA and DHA is an effective lifestyle strategy for CVD prevention, and the protective effect probably increases with dosage.
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Diagnostic Accuracy of IgA Anti-Transglutaminase and IgG Anti-Deamidated Gliadin for Diagnosis of Celiac Disease in Children under Two Years of Age: A Systematic Review and Meta-Analysis.
Catassi, GN, Pulvirenti, A, Monachesi, C, Catassi, C, Lionetti, E
Nutrients. 2021;14(1)
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Celiac disease typically develops within the first two years of life, however testing for it in children of this age is controversial. The immune test that is currently recommended for diagnosis in children, is both reliable and cost effective in adults, however, may not be suitable in this age group. This systematic review and meta-analysis aimed to determine whether extra immune testing is needed in children in addition to the more commonly recommended immune test. The results showed that based upon the 15 articles that were found, children with early celiac disease are possibly being mis-diagnosed due to a failure in the currently recommended testing not being sensitive enough. If a second immune test was added in combination with traditionally used tests, then it may ensure that diagnosis is more successful. This study could be used by healthcare practitioners to understand that current methods of testing for celiac disease in children, may give a false negative. To avoid this, it is recommended that children under two years of age have a combination of immune tests.
Abstract
The need of adding the determination of anti-deamidated gliadin peptide (DGP) IgG to anti-transglutaminase (TTG) IgA antibodies for diagnosis of celiac disease (CD) in children <2 years of age is controversial. We performed a systematic review and meta-analysis to evaluate, by head-to-head comparison, the diagnostic accuracy of TTG IgA and DGP IgG antibodies. We searched PubMed, MEDLINE, and Embase databases up to January 2021. The diagnostic reference was intestinal biopsy. We calculated the sensitivity and specificity of these tests and the odds ratio (OR) between the tests. Fifteen articles were eligible for the systematic review and ten were eligible for the meta-analysis. Sensitivity and specificity were 0.96 (95% confidence interval (CI), 0.91-0.98) and 0.96 (95% CI, 0.85-0.99) for DGP IgG and 0.93 (95% CI, 0.88-0.97) and 0.98 (95% CI, 0.96-0.99) for TTG IgA, respectively. TTG IgA specificity was significantly higher (OR 9.3 (95% CI, 2.3-37.49); p < 0.001) while the sensitivity of DGP IgG was higher without reaching statistical significance (OR: 0.6 (95% CI, 0.24-1.51); p = 0.28). Both the meta-analysis and the systematic review showed that some children with early CD are missed without the DGP IgG test. In children <2 years of age, TTG IgA is the best CD screening test; however, the addition of DGP IgG may increase the diagnostic sensitivity.
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Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data.
Goldenberg, JZ, Day, A, Brinkworth, GD, Sato, J, Yamada, S, Jönsson, T, Beardsley, J, Johnson, JA, Thabane, L, Johnston, BC
BMJ (Clinical research ed.). 2021;372:m4743
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Diet modification has long been recognised as a component for the treatment of diabetes. Diets low in carbohydrates have been extensively researched, as a diet for those with Type 2 Diabetes (T2D). This systematic review and meta-analysis aimed to determine the effect of low carbohydrate diets on T2D. The systematic review found 23 studies, including 1357 individuals, investigating the role of low carbohydrate diets on T2D outcomes. Low carbohydrate diet was defined as less than 130g of carbohydrate (less than 26% of calories from carbohydrate) for at least 12 weeks. Results reported at 6 months, found low carbohydrate diets were more effective than a normal diet at achieving diabetes remission. However, this effect diminished at 12 months, although longer term improvements were seen in blood lipids, weight loss and measures of prediabetes. It was concluded that individuals with T2D, eating a low carbohydrate diet for 6 months may reverse the disease. This study could be used by healthcare professionals to recommend a short-term low carbohydrate diet to individuals with T2D, to improve their chance of going into remission.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Type 2 diabetes remains a significant and worsening problem worldwide, despite many pharmaceutical developments and a global emphasis on glycemic control.
- This review highlights structured LCDs as a worthwhile option for the management and treatment of diabetes, providing an opportunity for Nutritional Therapy Practitioners to support clients in adopting evidence-informed, modifiable dietary and lifestyle changes for Type Two Diabetes.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- Type 2 diabetes is the most common form of diabetes, accounting for 90-95% of cases.
- Previous randomised trials assessed low carbohydrate diets (LCDs) (<26-45% of daily calories from carbohydrate) as encouraging to improve blood glucose control and outcomes of type 2 diabetes but did not systematically assessed remission of diabetes using low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes.
- Systematic reviews (SR) and meta-analyses represent the most valuable, reliable, and objective tool to summarise evidence from primary studies.
- This SR assessed 23 randomised controlled trials comparing LCDs with mostly low fat control diets in individuals / subjects / participants with type 2 diabetes. LCDs were defined as diets with less than 130 g/day or less than 26% of calories from carbohydrates, based on 2000 kcal/day. The authors used the Cochrane Risk of Bias tool 2.0 (RoB 2) to assess methodological quality of evidence, GRADE to assess the certainty of evidence
- On the basis of assessment of moderate to low certainty evidence, individuals / subjects / participants adhering to a LCD for six months may experience remission of type 2 diabetes without adverse consequences.
- Primary outcomes of interest were remission of type 2 diabetes (dichotomously defined as HbA1c <6.5% or fasting glucose <7.0 mmol/L), with or without the use of diabetes medication.
- Eight studies reported on remission of diabetes at six months. Pooled analysis showed that when remission was defined by an HbA1c level below 6.5% independent of medication use, LCDs increased remissions by an additional 32 per 100 patients followed (risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264; GRADE=moderate)
- When remission was defined by an HbA1c level below 6.5% and the absence of diabetes medication, LCDs increased remissions at a lower rate (risk difference 0.05, –0.05 to 0.14; 5 studies, n=199; GRADE=low)
- Additional primary outcomes were weight loss, HbA1c:
- 18 studies reported on Weight loss results (mean difference –3.46, 95% confidence interval –5.25 to –1.67; n=882 (note that positive results not sustained at 12 mo)
- Seventeen studies reported on HbA1c levels at six months, LCDs achieved greater reductions in HbA1c than did control diets (mean difference –0.47%, –0.60 to –0.34; n=747
- Limitations of study: 1) the definition of remission of diabetes, 2) Self-reported dietary intake data are prone to measurement error, particularly in dietary trials in which participants are not blinded
- This SR was funded in part by Texas A&M University.
- The authors declared no conflicts of interest.
Clinical practice applications:
The Authors highlight LCD diets incorporating carbohydrate of less than 130 g/day or less than 26% of calories (based on 2000 kcal/day) may be a safe strategy to help individuals with type 2 diabetes achieve weight loss and better blood glucose control over a six-month period. Results may not be sustained at 12 months.
Considerations for future research:
- The definition of diabetes remission needs clarification, especially with regard to threshold concentrations of Hb1Ac or fasting glucose and the use of diabetes medication.
- Safety concerns have been raised with LCDs. Although no significant or clinically important increase in total or serious adverse events was identified in this SR, these outcomes should be reported in future trials to confirm the certainty of evidence for safety.
- The Authors suggest long term, well designed, calorie controlled randomised trials are needed to determine the effects of LCD on sustained weight loss and remission of diabetes.
- Larger treatment effects for LCDs in shorter term trials (3 to <6 months), may be trialed as an effect modifier
Abstract
OBJECTIVE To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes. DESIGN Systematic review and meta-analysis. DATA SOURCES Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020. STUDY SELECTION Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible. DATA EXTRACTION Primary outcomes were remission of diabetes (HbA1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA1c, fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist. RESULTS Searches identified 14 759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I2=58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months. CONCLUSIONS On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42020161795.
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Ultra-Processed Food Consumption and Adult Mortality Risk: A Systematic Review and Dose-Response Meta-Analysis of 207,291 Participants.
Suksatan, W, Moradi, S, Naeini, F, Bagheri, R, Mohammadi, H, Talebi, S, Mehrabani, S, Hojjati Kermani, MA, Suzuki, K
Nutrients. 2021;14(1)
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Globally, consumption of ultra-processed foods (UPFs) has risen in most middle- or high-income countries and gradually displaced fresh and minimally processed foods. The aim of this study was to perform a systematic review and dose–response meta-analysis (of 7 studies) to determine if UPF intake is associated with mortality risk. Results indicate that UPF consumption was associated with an elevated risk of all-cause mortality, cardiovascular disease-cause mortality, and heart-cause mortality. However, there was no association between UPF consumption and cancer-cause mortality. Authors conclude that future studies should also investigate whether ultra-processing indices can demonstrate an association between diet and mortality compared with other nutritional quality scores/indices.
Abstract
We performed a systematic review and dose-response meta-analysis of observational studies assessing the association between UPF consumption and adult mortality risk. A systematic search was conducted using ISI Web of Science, PubMed/MEDLINE, and Scopus electronic databases from inception to August 2021. Data were extracted from seven cohort studies (totaling 207,291 adults from four countries). Using a random-effects model, hazard ratios (HR) of pooled outcomes were estimated. Our results showed that UPF consumption was related to an enhanced risk of all-cause mortality (HR = 1.21; 95% CI: 1.13, 1.30; I2 = 21.9%; p < 0.001), cardiovascular diseases (CVDs)-cause mortality (HR = 1.50; 95% CI: 1.37, 1.63; I2 = 0.0%; p < 0.001), and heart-cause mortality (HR = 1.66; 95% CI: 1.50, 1.85; I2 = 0.0%; p = 0.022), but not cancer-cause mortality. Furthermore, our findings revealed that each 10% increase in UPF consumption in daily calorie intake was associated with a 15% higher risk of all-cause mortality (OR = 1.15; 95% CI: 1.09, 1.21; I2 = 0.0%; p < 0.001). The dose-response analysis revealed a positive linear association between UPF consumption and all-cause mortality (Pnonlinearity = 0.879, Pdose-response = p < 0.001), CVDs-cause mortality (Pnonlinearity = 0.868, Pdose-response = p < 0.001), and heart-cause mortality (Pnonlinearity = 0.774, Pdose-response = p < 0.001). It seems that higher consumption of UPF is significantly associated with an enhanced risk of adult mortality. Despite this, further experimental studies are necessary to draw a more definite conclusion.
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Ultra-Processed Food Consumption and Adult Diabetes Risk: A Systematic Review and Dose-Response Meta-Analysis.
Moradi, S, Hojjati Kermani, MA, Bagheri, R, Mohammadi, H, Jayedi, A, Lane, MM, Asbaghi, O, Mehrabani, S, Suzuki, K
Nutrients. 2021;13(12)
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The growing incidence of chronic non-communicable diseases such as type two diabetes mellitus (T2DM) is the major healthcare concern worldwide. The aim of this study was to build on previous work by synthesizing the findings of observational studies investigating the association between ultra-processed food (UPF) intake and the risk of T2DM. This study is a systematic review and dose-response meta-analysis of five studies. Of the five included studies, four were prospective cohort study designs and the other was cross-sectional. Results demonstrate that higher UPF intake was associated with an increased risk of T2DM. Additionally, increasing the intake of processed foods by 10% leads to a 15% increase in the risk of T2DM. A linear positive association was found between UPF intake and the risk of T2DM. Authors conclude by pointing out that to be able to estimate better the actual burden of UPF intakes, new tools should be adapted or progressed to evaluate all UPF consumption dimensions, namely food class, UPF foods specific components, their effects on health and specific processes or additives.
Abstract
(1) Background: Recent individual studies have demonstrated that consumption of ultra-processed food (UPF) may be related to type two diabetes mellitus (T2DM). We aimed to synthesize the results from these individual studies by conducting an updated systematic review and meta-analysis of observational studies evaluating the association between UPF consumption and the risk of T2DM. (2) Methods: A systematic search was conducted using ISI Web of Science, PubMed/MEDLINE and Scopus electronic databases from inception up to August 2021. Data were extracted from five studies (one cross-sectional study and four cohort studies, totaling 230,526 adults from four different countries). Risk ratios (RR) of pooled results were estimated using a random-effects model. (3) Results: Our results revealed that higher UPF consumption was significantly associated with an increased risk of T2DM (RR = 1.74; 95% CI: 1.36, 2.22; I2 = 68.9%; p < 0.001; n = 5). Linear dose-response analysis indicated that each 10% increase in UPF consumption (kcal/d) was associated with a 15% higher risk of T2DM (RR = 1.15; 95% CI: 1.06, 1.26; I2 = 86.0%; p < 0.001; n = 5) among adults. Non-linear dose-response analysis demonstrated a positive linear association between UPF consumption and T2DM (pnonlinearity = 0.13, pdose-response < 0.001; n = 5) among adults. (4) Conclusions: A higher intake of UPF was significantly associated with an increased risk of T2DM. However, underlying mechanisms remain unknown and future experimental studies are warranted.
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Consumption of ultra-processed foods and health status: a systematic review and meta-analysis.
Pagliai, G, Dinu, M, Madarena, MP, Bonaccio, M, Iacoviello, L, Sofi, F
The British journal of nutrition. 2021;125(3):308-318
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Ultra-processed foods (UPF) are, according to the NOVA classification, “formulations of ingredients, mostly for industrial use only, derived from a series of industrial processes”. UPF represents an important and growing part of the world’s food supply. The aim of this study was to assess the relationship between UPF consumption as defined by NOVA and health status. This study is systematic review with meta-analysis of all the cross-sectional and cohort studies published to-date. At the end of the selection process, twenty-three articles were included in the qualitative analysis and nineteen in the quantitative analysis. Results indicate the possible association between high UPF consumption, worse cardiometabolic risk profile (reported by an increased risk of overweight/obesity, elevated waist circumference, reduced high-density lipoprotein-cholesterol levels and increased risk of the metabolic syndrome), and greater risk of all-cause mortality, cardiovascular disease, cerebrovascular disease and depression. Authors conclude that their findings have important public health implications, especially for food policymakers who should discourage the consumption of UPF and promote fresh and minimally processed foods to improve health status.
Abstract
Increasing evidence suggests that high consumption of ultra-processed foods (UPF) is associated with an increase in non-communicable diseases, overweight and obesity. The present study systematically reviewed all observational studies that investigated the association between UPF consumption and health status. A comprehensive search of MEDLINE, Embase, Scopus, Web of Science and Google Scholar was conducted, and reference lists of included articles were checked. Only cross-sectional and prospective cohort studies were included. At the end of the selection process, twenty-three studies (ten cross-sectional and thirteen prospective cohort studies) were included in the systematic review. As regards the cross-sectional studies, the highest UPF consumption was associated with a significant increase in the risk of overweight/obesity (+39 %), high waist circumference (+39 %), low HDL-cholesterol levels (+102 %) and the metabolic syndrome (+79 %), while no significant associations with hypertension, hyperglycaemia or hypertriacylglycerolaemia were observed. For prospective cohort studies evaluating a total population of 183 491 participants followed for a period ranging from 3·5 to 19 years, highest UPF consumption was found to be associated with increased risk of all-cause mortality in five studies (risk ratio (RR) 1·25, 95 % CI 1·14, 1·37; P < 0·00001), increased risk of CVD in three studies (RR 1·29, 95 % CI 1·12, 1·48; P = 0·0003), cerebrovascular disease in two studies (RR 1·34, 95 % CI 1·07, 1·68; P = 0·01) and depression in two studies (RR 1·20, 95 % CI 1·03, 1·40; P = 0·02). In conclusion, increased UPF consumption was associated, although in a limited number of studies, with a worse cardiometabolic risk profile and a higher risk of CVD, cerebrovascular disease, depression and all-cause mortality.
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Ultra-Processed Foods and Nutritional Dietary Profile: A Meta-Analysis of Nationally Representative Samples.
Martini, D, Godos, J, Bonaccio, M, Vitaglione, P, Grosso, G
Nutrients. 2021;13(10)
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In addition to the nutrient content of foods, the production and formulation methods of processed foods may also play a role in their effect on human health. The aim of this study was to systematically review the existing data from nationally representative surveys regarding UPF consumption in relation to dietary nutritional profiles, and to perform a meta-analysis (of 14 studies) of the results in order to understand the similarities or discrepancies that exist between countries. Results indicate a significant consumption of UPFs in the countries investigated, accounting for up to almost 80% of total caloric intake with confectionery (categorized as “cookies, pastries, and sweet bread”) and sugar-sweetened beverages representing the most consumed UPF groups. In fact, when considered in relation to other food groups, UPFs were not sporadically consumed in an isolated manner, but instead characterized entire dietary patterns and were consumed at the expense of unprocessed foods. Authors conclude that there is a consistent correlation between the increased consumption of UPFs and the worsening nutritional quality of diet.
Abstract
Excessive consumption of ultra-processed foods (UPFs), as described by the NOVA classification system, represents a potential threat to human health. The nutritional composition of UPFs may explain their observed adverse effects. The present study aimed to provide a quantitative meta-analysis of nationally representative surveys on the consumption of UPFs and the dietary/nutrient composition of respondents' diets. A systematic search for relevant studies published prior to July 2021 was conducted via electronic databases. The studies that provided the dietary/nutrient composition of foods categorized according to the NOVA classification system were selected. The association between UPFs and other dietary variables was modelled using ordinary least squares linear regression based on aggregated data extracted from the selected articles. Consumption of UPFs represented up to 80% of total caloric intake in the US and Canada, with confectionery and sugar-sweetened beverages being the most consumed items. When considered in relation to other food groups, an inverse linear relation between UPFs and less-processed foods was evident. Increased UPF intake correlated with an increase in free sugars, total fats, and saturated fats, as well as a decrease in fiber, protein, potassium, zinc, and magnesium, and vitamins A, C, D, E, B12, and niacin. In conclusion, the data indicate that increased UPF consumption negatively affects the nutritional quality of diets.
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Bioactive Compounds from Kefir and Their Potential Benefits on Health: A Systematic Review and Meta-Analysis.
Vieira, CP, Rosario, AILS, Lelis, CA, Rekowsky, BSS, Carvalho, APA, Rosário, DKA, Elias, TA, Costa, MP, Foguel, D, Conte-Junior, CA
Oxidative medicine and cellular longevity. 2021;2021:9081738
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Kefir – such as milk kefir, is the result of fermentation by a symbiotic complex of microorganisms that make up kefir grains. Lactic bacteria and acetic acid bacteria are the predominant species of this complex. An abundance of evidence speaks about the health benefits of kefir consumption. However, the identification of the bioactive compounds and controlled experiments are limited. This systematic review and meta-analysis sought to gather the current evidence on the health-promoting qualities and bioactive compounds from kefir consumption. Included were in-vitro and in-vivo studies encompassing 88 papers for the review and 45 papers for the meta-analysis. The authors looked at bioactive compounds in kefir and their antimicrobial and antioxidant activity. Before examining the impact of kefir on gut microbiome composition, the immune system, its anticancer properties, kefir's effects on fat metabolism, blood pressure, neurodegenerative diseases and osteoporosis. It also considered whether kefir from industrial production with a previously selected starter culture and artisanal kefir, using grains, exhibit different functional benefits. In conclusion, kefir has various bioactive compounds and this meta- analysis affirms it's health promoting benefits. Kefir and its compounds demonstrate antimicrobial, anticancer, and immune modulating properties. And artisanal kefir is associated with a more diverse microbial profile resulting in a wider array of bioactive compounds and antioxidant potential. How these bioactive compounds from kefir exert their effects is complex and hence the authors advocate for more standardised methodologies in future studies to strengthen existing findings.
Abstract
Despite evidence of health benefits from kefir administration, a systematic review with meta-analysis on bioactive compounds associated with these benefits is still absent in the literature. Kefir is fermented milk resulting from the metabolism of a complex microbiota in symbiosis. Recent researches have investigated the bioactive compounds responsible for the preventive and therapeutic effects attributed to kefir. However, differences in functional potential between industrial and artisanal kefir are still controversial. Firstly, we identified differences in the microbial composition among both types of kefir. Available evidence concerning the action of different bioactive compounds from kefir on health, both from in vitro and in vivo studies, was subsequently summarized to draw a primary conclusion of the dose and the intervention time for effect, the producer microorganisms, the precursor in the milk, and the action mechanism. Meta-analysis was performed to investigate the statistically significant differences (P < 0.05) between intervention and control and between both types of kefir for each health effect studied. In summary, the bioactive compounds more commonly reported were exopolysaccharides, including kefiran, bioactive peptides, and organic acids, especially lactic acid. Kefir bioactive compounds presented antimicrobial, anticancer, and immune-modulatory activities corroborated by the meta-analysis. However, clinical evidence is urgently needed to strengthen the practical applicability of these bioactive compounds. The mechanisms of their action were diverse, indicating that they can act by different signaling pathways. Still, industrial and artisanal kefir may differ regarding functional potential-OR of 8.56 (95% CI: 2.27-32.21, P ≤ .001)-according to the observed health effect, which can be associated with differences in the microbial composition between both types of kefir.
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The association between environmental exposures to chlordanes, adiposity and diabetes-related features: a systematic review and meta-analysis.
Mendes, V, Ribeiro, C, Delgado, I, Peleteiro, B, Aggerbeck, M, Distel, E, Annesi-Maesano, I, Sarigiannis, D, Ramos, E
Scientific reports. 2021;11(1):14546
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Chlordane is a synthetic organochlorine pesticide used for several decades in agriculture, but also in housing for pest control. Chlordane compounds are endocrine disrupting chemicals (EDCs), which means that they may affect the natural function of hormones by blocking, mimicking, displacing, or acting to subvert their roles. The aim of this study was to investigate whether exposure to chlordane compounds increases the risk of adiposity and diabetes in humans. This study is a systematic review and meta-analysis of 31 publications. Results demonstrate that there is no association between chlordane compounds and adiposity. However, there are higher odds of having diabetes-related features with increasing levels of all the chlordane compounds evaluated. Authors conclude that an international agreement on methods to measure both exposure and outcome variables and to conduct epidemiological studies could increase the knowledge on how adverse effects of exposure to various stressors (exposome) can influence human health.
Abstract
Chlordane compounds (CHLs) are components of technical chlordane listed in the Stockholm convention on persistent organic pollutants identified as endocrine disrupting chemicals (EDCs) and may interfere with hormone biosynthesis, metabolism or action resulting in an unbalanced hormonal function. There is increasing scientific evidence showing EDCs as risk factors in the pathogenesis and development of obesity and obesity-related metabolic syndromes such as type 2 diabetes, but there is no systematized information on the effect of CHLs in humans. Our aim is to identify the epidemiological data on the association between CHLs with adiposity and diabetes using a systematic approach to identify the available data and summarizing the results through meta-analysis. We searched PubMed and Web of Science from inception up to 15 February 2021, to retrieve original data on the association between chlordanes, and adiposity or diabetes. For adiposity, regression coefficients and Pearson or Spearman correlation coefficients were extracted and converted into standardized regression coefficients. Data were combined using fixed effects meta-analyses to compute summary regression coefficients and corresponding 95% confidence intervals (95% CI). For the association between chlordanes and diabetes, Odds ratios (ORs) were extracted and the DerSimonian and Laird method was used to compute summary estimates and respective 95% CI. For both, adjusted estimates were preferred, whenever available. Among 31 eligible studies, mostly using a cross-sectional approach, the meta-analysis for adiposity was possible only for oxychlordane and transchlordane, none of them were significantly associated with adiposity [(β = 0.04, 95% CI 0.00; 0.07, I2 = 89.7%)] and (β = 0.02, 95% CI - 0.01; 0.06), respectively. For diabetes, the estimates were positive for all compounds but statistically significant for oxychlordane [OR = 1.96 (95% CI 1.19; 3.23)]; for trans-nonachlor [OR = 2.43 (95% CI 1.64; 3.62)] and for heptachlor epoxide [OR = 1.88 (95% CI 1.42; 2.49)]. Our results support that among adults, the odds of having diabetes significantly increase with increasing levels of chlordanes. The data did not allow to reach a clear conclusion regarding the association with adiposity.