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DANONE INSTITUTE INTERNATIONAL Systematic Review of Yoghurt for Weight Management Outcomes
Final Protocol
JULIE GLANVILLE, Associate Director JAQUI EALES,Associate
HANNAH WOOD, Information Specialist
26 SEPTEMBER 2014
All reasonable precautions have been taken by YHEC to verify the information contained in this publication. However, the published material is being distributed without warranty of any kind, either expressed or implied. The responsibility for the interpretation and use of the material lies with the reader. In no event shall YHEC be liable for damages arising from its use.
Contents Page No. Acknowledgements Abbreviations
Section 1: Introduction 2 1.1 Defining Yoghurt 2
Section 2: Objectives 4
Section 3: Methods 5 3.1 Research Question 5 3.2 Search Strategy 8 3.3 Selection of Eligible Studies 11 3.4 Data Extraction 11 3.5 Quality Assessment 12 3.6 Data synthesis 12
Section 4: Report 14 4.1 Draft Report 14 4.2 Final Report 14
Section 5: Timeline 15 References Appendices: Appendix A: PRISMA flow diagram Appendix B: PRISMA checklist Appendix C: Protocol changes
i
Abbreviations BMI Body mass index CI Confidence interval CRD Centre for reviews and dissemination DII Danone Institute International EFSA European food safety authority HRQoL Health-related quality of life OR Odds ratio PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses SR Systematic review RCT Randomized control trial RR Risk ratio WMD Weighted mean difference YHEC York Health Economics Consortium
Section 1 2
Section 1: Introduction
York Health Economics Consortium (YHEC) has been commissioned by Danone Institute
International (DII) to conduct a systematic review (SR) of the effect of yoghurt consumption
on weight management outcomes. This document is the protocol for this work, and sets out
how YHEC will approach this task and its constituent tasks.
1.1 DEFINING YOGHURT
The Codex Alimentarius international food standards define yoghurt as a form of fermented
milk that contains symbiotic cultures of Streptococcus thermophiles and Lactobacillus
delbrueckii subsp. Bulgaricus. To be called a yoghurt a fermented milk product must
contain milk protein, milk fat, lactic acid, ethanol, microorganisms and yeasts in the proper
proportions (Table 1)(1). Probiotic yogurt is differentiated from conventional yoghurt through
the addition of further strains of probiotic bacteria (2). This review focuses on the
effectiveness of yoghurt containing the symbiotic cultures Streptococcus thermophiles and
Lactobacillus delbrueckii subsp. Bulgaricus, as defined by the Codex Alimentarius.
Table 1: The composition of fermented milk products (1) Fermented Milk Yoghurt, Alternate
Culture Yoghurt and Acidophilus
milk
Kefir Kumys
Milk protein Min. 2.7% Min. 2.7% Min. 2.7%
Milk fat Less than 10% Less than 15% Less than 10% Less than 10%
Titrable acidity, expressed as % lactic acid (%m/m)
Min. 0.3% Min. 0.6% Min. 0.6% Min. 0.7%
Ethanol(% vol/w) Min. 0.5%
Sum of microorganisms constituting the starter culture (cfu/g, In total)
Min. 107 Min. 10
7 Min. 10
7 Min. 10
7
Labelled microorganisms (cfu.g, total)
Min. 106 Min. 10
6
Yeasts (cfu/g) Min. 104 Min. 10
4
Vol. = volume; cfu/g = colony-forming units per gram; Min. = minimum.
The beneficial health effects of yoghurt have been the subject of investigation for over a
century. A range of research designs have been employed in the construction of an
international evidence base, including observational studies and experimental studies (3, 4).
The efficacy of yoghurt has been investigated in relation to a wide range of separate and
Section 1 3
overlapping outcomes including weight management (5), type 2 diabetes (6), cardio-vascular
disease risk (7), bone health (8), dental health (9), the risk of various forms of cancer (10),
gastro-intestinal health (11), diarrhoea symptoms (12), lactose intolerance (13), malnutrition
(14), immunological parameters(15), and overall mortality (16).
Meta-analyses and systematic reviews have been conducted in relation to only a few of
these outcomes. Their limited results suggest that consuming yoghurt may reduce the risk
of developing type 2 diabetes (17-19), but may have no effect on the risk of developing
colorectal cancer (20), hypertension (21) or on overall mortality (22).
In recent years considerable attention has been paid to understanding the health benefits of
probiotic yoghurts, with increasing numbers of systematic reviews having been conducted in
this area. DII now wish to conduct a systematic review of the effect of standard yoghurt
consumption on outcomes related to weight management. There is particular interest in
identifying data for specific subgroups of the general apparently healthy adult population,
such as those at risk of diabetes, and for investigating the effects in different ethnic groups.
Section 2 4
Section 2: Objectives
The objective of this project is to produce a systematic review of the effect of standard
yoghurt consumption on weight management outcomes.
Section 3 5
Section 3: Methods
A systematic review involves the systematic and transparent identification, selection,
extraction and synthesis of studies relevant to the research question (23). The first stage of
this protocol is to define the research question and the inclusion and exclusion criteria (Table
3.1).
3.1 RESEARCH QUESTION
To be included in the systematic review, studies must meet all of the following inclusion
criteria.
3.1.1 Study types
Relevant comparative studies will be limited to the following study types:
Randomized controlled trials (RCTs) including quasi-RCTs;
Controlled clinical trials;
Comparative observational studies (including cross sectional studies, cohort studies
and case control studies).
Studies with relevant comparative designs published as abstracts, conference presentations
or unpublished reports will be included in the review if they report all items from Section 3.1.
Trial protocols, where the study results have not yet been reported, will be noted in a table of
forthcoming studies.
We will examine any relevant systematic reviews of evidence on the effects of yoghurt on
weight management outcomes to identify any additional studies that might be eligible to be
included in the systematic review.
The following non-comparative study designs will not be eligible for inclusion:
Case reports;
Case series.
Letters, comments and editorials and studies not published in English will not be eligible for
inclusion in the systematic review.
3.1.2 Participants
To be included in the review eligible studies will examine the effects of yoghurt on weight
management in the apparently healthy adult population (18-65 years). Studies that contain a
Section 3 6
mixed population with a proportion of the population aged over 65 years of age or younger
than 18 will be treated as eligible if there are separate results presented for the 18-65 age
group.
Studies that contain a mixed population with a proportion of the population aged over 65
years of age will be treated as eligible, if there is a total of 20% or less of the study
population who are either aged 65 or younger than 18 years of age.
Studies reporting data for specific subgroups of the general population who are at high risk
will also be eligible, for example people with insulin resistance, diabetes or obesity (BMI
between 30 and 40).
Studies only examining the effects of yoghurt on weight management in the following
populations will be excluded:
Study populations comprising only people with severe or morbid obesity (BMI
≥40.00)1;
Study populations with a single specific disease or symptom such as anaemia,
which are not representative of the apparently healthy general population;
People training for or undertaking physical activity at a professional level (e.g.
professional sports people, soldiers or fire service personnel);
Any animal population;
In vitro studies;
Studies using technologies that mimic stomachs.
3.1.3 Interventions
Studies eligible for inclusion in this review will include the following interventions:
Yoghurt, or any of its synonyms (Yogurt; Yoghourt; Yaourt; Joghurt; Yogourt;
Yaghourt; Yahourth; Yoghurd; Joghourt; Jogourt; Maas (Amasi); Dahi; Doi; Perugu;
Thayir; Mosaru; Curd; Matsun; Matsoon; Matsoun; Matxoun; Madzoon; Madzoun;
Mancun; Matson; Matsoni; Dadiah; Dadih; Stragisto).
Studies will not be eligible for inclusion where yoghurt is featured as an intervention in
combination with another substance (e.g. CLA/vitamins/Olibra) which is the main focus of
the study. In those studies, yoghurt is being used as a carrier substance for an active
ingredient and hence is not the focus of the investigation.
Studies reporting the following interventions will not be eligible for inclusion:
Probiotic yoghurt;
Fermented milk, kefir and kumys;
1 World Health Organiszation. Global database on body mass index [web page]. Geneva: WHO; 2014.
http://apps.who.int/bmi/index.jsp?introPage=intro_3.html
Section 3 7
Fermented baby formula;
Milk.
For the purposes of this review, yoghurt which is reported to contain any bacteria other than
Streptococcus thermophilius and Lactobacillus delbrueckii subsp. Bulgaricus will not be
eligible for inclusion.
Only studies reporting oral consumption of yoghurt will be eligible for inclusion in the review.
Topical application of yoghurt as an intervention will not be eligible for inclusion.
3.1.4 Comparators
Eligible studies must compare yoghurt with one or more of the following interventions:
Any non-probiotic yoghurt only (e.g. low fat yoghurt, full fat yoghurt);
Any non-yoghurt substance;
Placebo not including live bacteria;.
Any other non-yoghurt intervention (e.g. yoghurt consumption vs nutritional
counselling).
Studies that compare yoghurt with the following only will not be eligible for inclusion in the
systematic review:
Yoghurt containing any other active substance, where the active substance is the
main focus of the study;2
Probiotic yoghurt;
Fermented buffalo milk.
3.1.5 Outcomes
To be included in this review studies will assess the interventions featured in section 3.1.3 in
relation to at least one of the following weight management outcomes:
Percent body fat (fat body mass or fat mass expressed as a proportion, ratio or
percentage);
Percent lean body mass (lean fat expressed as a proportion, ratio or percentage);
Body weight;
Body Mass Index (BMI);3
Waist Circumference;
Composite measures related to weight management (for example measures
combining body weight, BMI and/or waist circumference).
2 For example yoghurt with CLA/vitamins/Olibra vs yoghurt without CLA/vitamins/Olibra would be excluded from
the systematic review.. 3 Body Mass Index (BMI) is defined as (weight/height
2)(24)
Section 3 8
Table 3.1: Summary of inclusion/exclusion criteria
PICOS Inclusion criteria Exclusion criteria
Participants The healthy adult population (18-65 years)
Human populations with specific diseases or studies only in the morbidly obese;
People training for or undertaking high level physical performances;
Any animal population;
In vitro studies;
Studies using technologies that mimic stomachs.
Interventions Yoghurt (consumed orally) Probiotic yoghurt;
Non-probiotic yoghurt used as the carrier base for other active substances;
Fermented milk, kefir and kumys;
Fermented baby formula;
Milk;
Yoghurt with bacteria other than Streptococcus thermophilius and Lactobacillus delbrueckii subsp. Bulgaricus;
Topical application of yoghurt.
Comparators Any non-probiotic yoghurt;
Any non-yoghurt intervention;
Any placebo or control product that does not contain other active probiotics and/or prebiotics.
Probiotic yoghurt;
Fermented buffalo milk;
Non-probiotic yoghurt used as the carrier base for other active substances.
Outcomes Body weight
Body Mass Index (BMI)
Waist Circumference
Fat body mass
Lean body mass
Composite measures
Study types RCTs;
Controlled clinical trials
Comparative observational studies (Cross sectional studies, cohort studies, case-control studies).
Full papers, abstracts and conference presentations, trial reports and unpublished reports will be eligible.
Case reports
Case series
Letters
Comments
Editorials
3.2 SEARCH STRATEGY
The systematic review involves a search for relevant studies. The search will be very
sensitive since it involves only the search concept for yoghurt and uses many synonyms to
capture that concept. The strategy explicitly excludes records which are letters, editorials,
comments or case reports, where the databases offer such options. Where databases offer
the facility, animal studies will be excluded using a well-established search approach. The
Medline strategy is shown in Figure 3.1.
Section 3 9
Figure 3.1 Medline search strategies to identify studies reporting the health
benefits of yoghurt
1 yogurt/
2 streptococcus thermophilus/ 3 lactobacillus delbrueckii/ 4 (yogurt$ or yoghurt$ or yoghourt$ or yaourt$ or joghurt$ or yogourt$ or yaghourt$ or
yahourth$ or yoghurd$ or joghourt$ or jogourt$).ti,ab. 5 (maas or amasi$1 or dahi$1 or da-hi$1 or dohi$1 or meesti$1 or perugu$1 or thayir$1
or thayiru$1 or mosaru$1 or curd$1 or matsun$1 or matsoon$1 or matsoun$1 or matzoun$1 or madzoon$1 or madzoun$1 or matson$1 or matsoni$1 or dadiah$1 or dadih$1 or stragisto$1 or q?zana$1 or dhahi$1 or dhaunro$1 or juju dhau$1 or rahmjoghurt$ or jameed$1 or zabadi$1 or labni$1 or lebni$1 or labneh$1 or m?st chekide$1).ti,ab.
6 (streptococcus adj3 thermophilus).ti,ab. 7 s thermophilus.ti,ab. 8 (lactococcus adj3 thermophilus).ti,ab. 9 l thermophilus.ti,ab. 10 (lactobacillus adj3 delbruecki$).ti,ab. 11 l delbruecki$.ti,ab. 12 bulgaricus.ti,ab. 13 or/1-12 14 (letter or editorial or comment or case reports).pt. 15 case report.ti. 16 animals/ not (animals/ and humans/) 17 13 not (14 or 15 or 16)
The searches will not be limited by date or language, so that if required studies in languages
other than English can be identified for consideration in any future updates.
3.2.1 Resources Searched
The literature search will be conducted in a range of relevant databases to identify studies
investigating the health benefits of yoghurt (Table 3.3). Grey literature will be identified via
OAISTER, OpenGrey and NTIS. Unpublished studies will be identified from, clinical trial
registries and conference proceedings.
Table 3.3: Databases and resources to be searched
Database Interface
MEDLINE and MEDLINE In-Process OvidSP
EMBASE OvidSP
Cochrane Database of Systematic Reviews (CDSR) Cochrane Library/Wiley Interscience
Cochrane Central Register of Controlled Trials (CENTRAL)
Cochrane Library/Wiley Interscience
DARE Database of Abstracts of Reviews of Effects (DARE)
CRD interface
Health Technology Assessment Database (HTA) CRD interface
Science Citation Index (SCI) Web of Knowledge
Conference Proceedings Citation Index – Science (CPCI-S)
Web of Knowledge
Section 3 10
Database Interface
African Index Medicus http://indexmedicus.afro.who.int/
LILACS http://search.bvsalud.org/portal/
OAISTER http://oaister.worldcat.org/
OpenGrey http://www.opengrey.eu/
NTIS Proquest Dialog
Biosis Proquest Dialog
CAB Abstracts Proquest Dialog
Food Science and Technology Abstracts Proquest Dialog
ClinicalTrials.gov www.clinicaltrials.gov
ICTRP (trials) http://www.who.int/ictrp/en/
Information on ongoing or recently completed studies, unpublished research, and research
reported in the grey literature will be identified by searching selected major conference
proceedings from the last four years:
ESPEN congress;
The International Scientific Conference on Nutraceuticals and Functional Foods
(Food and function);
European Nutrition Conference (FENS);
Federation of American Societies for Experimental Biology (FASEB);
American Dietetics Association;
Federation of European Microbiological Societies (FEMS);
American Society of Microbiology (ASM);
American College of Gastroenterology (ACG) Annual Scientific Meetings;
Digestive Disease Week;
British Society of Gastroenterology meetings;
United European Gastroenterology Week;
American Dairy Products Institute (ADPI)
International Dairy Federation (IDF)
International Functional Food Conference
American Society for Nutrition (ASN)
European Society for Paediatric Gastroenterology Hepatology and Nutrition
(ESPGHAN)
North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition
(NASPGHAN)
International Scientific Association for Probiotics and Prebiotics ISAPP)
Obesity Society Annual Scientific Meeting
European Congress on Obesity (European Association for the Study of Obesity)
American Diabetes Association’s Scientific Sessions
(American) Endocrine Society Annual meeting and ENDO
The reference lists of relevant reviews, trials and studies will be searched to identify any
further studies.
The results will be loaded into EndNote bibliographic software and deduplicated using
several algorithms.
Section 3 11
3.3 SELECTION OF ELIGIBLE STUDIES
Record selection will be undertaken using several passes.
The first pass will be undertaken by two reviewers independently to rapidly remove obviously
irrelevant records including those records which report animal studies, address probiotic
yoghurts,, include ineligible study design features, or report outcomes that are not of interest.
Then initial record selection from the title and abstract will be undertaken by two reviewers
independently (second pass). The reviewers will be seeking to identify the studies most
likely to contain evidence of the effects of yoghurt on weight management outcomes. If
there is uncertainty about whether a record is relevant it will be selected for further checking.
At this stage advice on inclusion criteria refinement may be sought from DII.
The full text of potentially relevant studies will then be obtained, if it has not been already.
The full papers will be assessed for relevance by two reviewers independently (third pass).
Discrepancies will be resolved through discussion or by consulting a third reviewer. Studies
that are considered ineligible at this stage will be listed in an ‘Excluded Studies’ table with
reasons for exclusion (EFSA 2010: section 4.1.1.5). This table will be included in the final
report. Studies that we are unable to obtain will be listed in another table.
Where questions about study eligibility remain, we will contact the study’s primary
investigator.
The number of studies identified by the search and excluded at various stages will be
recorded and reported in a PRISMA study flow diagram (see Appendix A) following the
PRISMA checklist (Appendix B)(25).
3.4 DATA EXTRACTION
At the data extraction stage some studies, on close inspection, may prove ineligible. These
studies will be described in an ‘excluded studies’ table with the reasons for exclusion
reported. The number of records lost at this stage of the review process will be documented
in the flow diagram (see Appendix A).
We will develop a data extraction template in Excel. Data likely to be extracted from each
study include:
Description of the study design (for example, duration, participant selection),
interventions/actions investigated and details of how the interventions were
delivered and by whom;
Country of study and ethnicity of participants;
Inclusion and exclusion criteria and their characteristics at baseline, along with any
differences between study groups, where applicable;
Section 3 12
Details of any “at risk”4 subgroups of the population;
Numbers of participants in the study and details of numbers lost to follow up or who
withdrew;
Details of the primary and secondary outcomes investigated and the measures
used to investigate those outcomes, and the results;
Method of randomisation (if applicable) or sample selection.
The methods of analysis will be collected along with details of subgroup analyses and their
rationale. Information about whether analyses were pre-planned or post-hoc can also be
collected.
Inadequately reported or missing data will be explicitly noted in the Excel spreadsheet.
Data will be extracted by two reviewers independently. Any discrepancies will be resolved
through discussion or by consulting a third reviewer.
Where the information that we need is not presented in the paper we will contact the study
authors to ask for the data.
3.5 QUALITY ASSESSMENT
We will undertake quality assessment of the eligible studies using appropriate quality
appraisal checklists, as well as conducting detailed extraction of study methods and
outcomes. The internal and external validity of all eligible studies will be quality assessed.
RCTs will be assessed using the Cochrane risk of bias tool and cohort studies will be
assessed using the CRD cohort studies checklist (26) (Appendix C).
Quality assessment will be conducted by two researchers independently. The two data sets
will then be consolidated and any disagreements will be discussed between the reviewers.
3.6 DATA SYNTHESIS
The studies will be summarised in tables providing data on their methods and results. We
will assess the similarity of studies and availability of data, and where studies are similar
enough and data are available we may be able to undertake statistical pooling, in the form of
a meta-analysis. If appropriate, the results will be statistically pooled for the outcomes of
interest using a fixed-effect model where results are homogeneous and random-effects
models where results are heterogeneous. The methods of pooling will be described. For
dichotomous outcomes, the results will be presented as relative risks (RR) with 95%
confidence intervals (CIs). Hazard ratios (HR) will be presented for any time-to-event
analyses. For continuous outcomes, results will be presented as a weighted mean
difference (WMD), with 95% confidence intervals (CIs). Heterogeneity will be assessed
4 “At risk” may include people with diabetes, or with risk factors for chronic disease such as hypertension, high
LDL or who are obese.
Section 3 13
using the chi-squared and I-squared statistics where an I2 of 0-25% represents no
heterogeneity, 25-50% represents moderate heterogeneity, 50-75% represents substantial
heterogeneity and 75-100% represents considerable heterogeneity. The results from any
meta-analyses will be graphically presented as forest plots. All analyses will be conducted
using the Review Manager (RevMan) software. The strengths and weaknesses of the
synthesis will also be discussed.
Sensitivity analysis will be undertaken, if data permit, by the ethnic origin of study
populations.
We will provide a narrative summary, irrespective of the feasibility of pooling. This will
provide an exploration of the relationship between studies and will discuss patterns (if
appropriate) in the data. An overall assessment of the strength of the research evidence in
relation to the research questions will be provided.
Section 4 14
Section 4: Report
4.1 DRAFT REPORT
Although the final style and format of the report is to be agreed, we anticipate that we will
present the report according to the PRISMA reporting guidelines (25).
The report will be structured as follows and content will be detailed (as far as possible):
Executive summary;
List of tables and figures;
Introduction and background to the research question;
Objectives of the review;
Description of the research methods;
o Eligibility criteria;
o Search strategy;
o Record selection
o Quality assessment;
o Study data extraction;
o Analyses of the results.
Results;
o Study selection;
o Study characteristics;
o Quality assessment;
o Syntheses of results;
o Any additional analyses (e.g. subgroup analysis).
Discussion;
o Summary of the evidence;
o Limitations;
o Conclusions.
References;
Included studies tables;
Excluded studies tables;
Forthcoming studies table;
PRISMA checklist;
Search strategies.
4.2 FINAL REPORT
Following comments from DII, we will amend the draft report as necessary. These
amendments, once agreed, will form the final report.
Section 5 15
Section 5: Timeline
The timescale for this project is shown in Table 5.1. The timeline is based on an estimate of
the numbers of studies likely to be included at each stage of review. The timelines may be
impacted by waiting for responses to queries from authors and the client. We have taken
account of staff summer holidays, in the timelines.
Table 5.1: Timelines for the systematic review
Activity Completion date
Project initiation meeting held TBC
Production of draft protocol 29/08/14
Protocol finalised 23/09/14
Database searches completed 07/10/14
Record selection / ordering / further selection completed
21/10/14
Full text assessment for relevance completed (approx. 85 studies)
27/10/14
Record extraction and quality assessment completed (approx. 40 studies)
17/11/14
Synthesis and prepare draft report 15/12/14
Revised report (in light of DII comments) December 2014/January 2015
R:\Projects\JMG\JMG355 - Danone Yoghurt and Weight Management\Admin\Yoghurt and Weight management
Final protocol 26 Sept 2014.docx
JMG 26/09/14
References 16
References 1. Codex Committee on Milk and Milk Products. Codex Standard for Fermented Milks (2nd Ed). In. New Zealand: Codex Alimentarius 2010. p. 11. 2. Meyer AL, Elmadfa I, Herbacek I, Micksche M. Probiotic, as well as conventional yogurt, can enhance the stimulated production of proinflammatory cytokines. Journal of Human Nutrition and Dietetics. 2007;20(6):590-98. DOI: 10.1111/j.1365-277X.2007.00807.x. 3. Bonjour JP, Benoit V, Payen F, Kraenzlin M. Consumption of yogurts fortified in vitamin D and calcium reduces serum parathyroid hormone and markers of bone resorption: a double-blind randomized controlled trial in institutionalized elderly women. J Clin Endocrinol Metab. 2013;98(7):2915-21. DOI: http://dx.doi.org/10.1210/jc.2013-1274. 4. Douglas SM, Ortinau LC, Hoertel HA, Leidy HJ. Low, moderate, or high protein yogurt snacks on appetite control and subsequent eating in healthy women. Appetite. 2013;60(1):117-22. DOI: http://dx.doi.org/10.1016/j.appet.2012.09.012. 5. Burns AA, Lindmark L, Livingstone MBE, Mullaney U, Rowland I, Welch RW. Consumption of yoghurt containing modified fat increases satiety and reduces subsequent food intake. Proceedings of the Nutritional Society. [serial on the internet]. 1998; 57: 121a. Available from: URL. [cited Date Accessed]; 6. O'Connor LM, Lentjes MA, Luben RN, Khaw KT, Wareham NJ, Forouhi NG. Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary. Diabetologia. 2014. DOI: 10.1007/s00125-014-3176-1. 7. Buyuktuncer Z, Fisunoglu M, Guven GS, Unal S, Besler HT. The cholesterol lowering efficacy of plant stanol ester yoghurt in a Turkish population: A double-blind, placebo-controlled trial. Lipids in Health and Disease. 2013;12(1). DOI: http://dx.doi.org/10.1186/1476-511X-12-91. 8. Heaney RP, Rafferty K, Dowell MS. Effect of yogurt on a urinary marker of bone resorption in postmenopausal women. Journal of the American Dietetic Association. 2002;102(11):1672-74. 9. Telgi RL, Yadav V, Telgi CR, Boppana N. In vivo dental plaque pH after consumption of dairy products. Gen Dent. 2013;61(3):56-9. 10. Kurahashi N, Inoue M, Iwasaki M, Sasazuki S, Tsugane AS. Dairy product, saturated fatty acid, and calcium intake and prostate cancer in a prospective cohort of Japanese men. Cancer Epidemiol Biomarkers Prev. 2008;17(4):930-7. DOI: http://dx.doi.org/10.1158/1055-9965.EPI-07-2681. 11. Ballesta S, Velasco C, Borobio MV, Arguelles F, Perea EJ. [Fresh versus pasteurized yogurt: comparative study of the effects on microbiological and immunological parameters, and gastrointestinal comfort]. Enferm Infecc Microbiol Clin. 2008;26(9):552-7. 12. Pashapour N, Iou SG. Evaluation of yogurt effect on acute diarrhea in 6-24-month-old hospitalized infants. Turk J Pediatr. 2006;48(2):115-8. 13. Adibi P, Mirshahzadeh P, Sadeghizadeh A. Dairy intolerance syndrome in Iranian young adult. J. 2009;14(6):357-66. 14. Sazawal S, Habib A, Dhingra U, Dutta A, Dhingra P, Sarkar A, et al. Impact of micronutrient fortification of yoghurt on micronutrient status markers and growth - a randomized double blind controlled trial among school children in Bangladesh. BMC Public Health. 2013;13:514. DOI: http://dx.doi.org/10.1186/1471-2458-13-514. 15. Olivares M, Paz Diaz-Ropero M, Gomez N, Sierra S, Lara-Villoslada F, Martin R, et al. Dietary deprivation of fermented foods causes a fall in innate immune response. Lactic acid bacteria can counteract the immunological effect of this deprivation. J Dairy Res. 2006;73(4):492-8. 16. Goldbohm RA, Chorus AMJ, Garre FG, Schouten LJ, Brandt PA. Dairy consumption and 10-y total and cardiovascular mortality: a prospective cohort study in the Netherlands. Am J Clin Nutr. 2011;93(3):615-27.
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17. Aune D, Norat T, Romundstad P, Vatten LJ. Dairy products and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Am J Clin Nutr. 2013;98(4):1066-83. DOI: http://dx.doi.org/10.3945/ajcn.113.059030. 18. Gao D, Ning N, Wang C, Wang Y, Li Q, Meng Z, et al. Dairy products consumption and risk of type 2 diabetes: systematic review and dose-response meta-analysis. PLoS ONE. 2013;8(9):e73965. DOI: http://dx.doi.org/10.1371/journal.pone.0073965. 19. Tong X, Dong JY, Wu ZW, Li W, Qin LQ. Dairy consumption and risk of type 2 diabetes mellitus: a meta-analysis of cohort studies. Eur J Clin Nutr. 2011;65(9):1027-31. DOI: http://dx.doi.org/10.1038/ejcn.2011.62. 20. Aune D, Lau R, Chan DSM, Vieira R, Greenwood DC, Kampman E, et al. Dairy products and colorectal cancer risk: A systematic review and meta-analysis of cohort studies. Annals of Oncology. 2012;23(1):37-45. DOI: http://dx.doi.org/10.1093/annonc/mdr269. 21. Soedamah-Muthu SS, Verberne LD, Ding EL, Engberink MF, Geleijnse JM. Dairy consumption and incidence of hypertension: a dose-response meta-analysis of prospective cohort studies. Hypertension. 2012;60(5):1131-7. DOI: http://dx.doi.org/10.1161/HYPERTENSIONAHA.112.195206. 22. O'Sullivan TA, Hafekost K, Mitrou F, Lawrence D. Food sources of saturated fat and the association with mortality: a meta-analysis. Am J Public Health. 2013;103(9):e31-42. DOI: http://dx.doi.org/10.2105/AJPH.2013.301492. 23. European Food Safety Authority. Application of systematic review methodology to food and feed safety assessments to support decision making. EFSA Journal. 2010;8(6):1637. 24. Cole TJ, Bellizzi MC, Flegal KM, Dietz WH. Establishing a standard definition for child overweight and obesity worldwide: international survey; 2000. 25. Liberati A, Altman D, Tezlaff J, Mulrow C, Gotzsche P, Ioannidis J, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ. 2009;339:b2700. 26. Higgins J, Green S, (editors). Cochrane Handbook for Systematic Reviews of Interventions: The Cochrane Collaboration; 2011.
APPENDIX A
PRISMA flow diagram
Appendix A i
PRISMA 2009 Flow Diagram
Records identified through database searching
(n = )
Scre
en
ing
Inclu
de
d
Elig
ibili
ty
Iden
tificatio
n
Additional records identified through other sources
(n = )
Records after duplicates removed (n = )
Records screened (n = )
Records excluded (n = )
Full-text articles assessed for eligibility
(n = )
Full-text articles excluded, with reasons
(n = )
Studies included in qualitative synthesis
(n = )
Studies included in quantitative synthesis
(meta-analysis) (n = )
APPENDIX B
PRISMA checklist
Appendix B i
Section/topic # Checklist item Reported on page #
TITLE
Title 1 Identify the report as a systematic review, meta-analysis, or both. Title page
ABSTRACT
Structured summary 2 Provide a structured summary including, as applicable: background; objectives; data sources; study eligibility criteria, participants, and interventions; study appraisal and synthesis methods; results; limitations; conclusions and implications of key findings; systematic review registration number.
INTRODUCTION
Rationale 3 Describe the rationale for the review in the context of what is already known.
Objectives 4 Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).
METHODS
Protocol and registration
5 Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.
Eligibility criteria 6 Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.
Information sources 7 Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.
Search 8 Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.
Study selection 9 State the process for selecting studies (i.e., screening, eligibility, included in systematic review, and, if applicable, included in the meta-analysis).
Data collection process 10 Describe method of data extraction from reports (e.g., piloted forms, independently, in duplicate) and any processes for obtaining and confirming data from investigators.
Appendix B ii
Section/topic # Checklist item Reported on page #
Data items 11 List and define all variables for which data were sought (e.g., PICOS, funding sources) and any assumptions and simplifications made.
Risk of bias in individual studies
12 Describe methods used for assessing risk of bias of individual studies (including specification of whether this was done at the study or outcome level), and how this information is to be used in any data synthesis.
Summary measures 13 State the principal summary measures (e.g., risk ratio, difference in means).
Synthesis of results 14 Describe the methods of handling data and combining results of studies, if done, including measures of consistency (e.g., I2) for each meta-analysis.
Risk of bias across studies
15 Specify any assessment of risk of bias that may affect the cumulative evidence (e.g., publication bias, selective reporting within studies).
Additional analyses 16 Describe methods of additional analyses (e.g., sensitivity or subgroup analyses, meta-regression), if done, indicating which were pre-specified.
RESULTS
Study selection 17 Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.
Study characteristics 18 For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.
Risk of bias within studies
19 Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).
Results of individual studies
20 For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.
Synthesis of results 21 Present results of each meta-analysis done, including confidence intervals and measures of consistency.
Risk of bias across studies
22 Present results of any assessment of risk of bias across studies (see Item 15).
Additional analysis 23 Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression [see Item 16]).
DISCUSSION
Appendix B iii
Section/topic # Checklist item Reported on page #
Summary of evidence 24 Summarize the main findings including the strength of evidence for each main outcome; consider their relevance to key groups (e.g., healthcare providers, users, and policy makers).
Limitations 25 Discuss limitations at study and outcome level (e.g., risk of bias), and at review-level (e.g., incomplete retrieval of identified research, reporting bias).
Conclusions 26 Provide a general interpretation of the results in the context of other evidence, and implications for future research.
FUNDING
Funding 27 Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review.
This project was funded by Danone Institute International
APPENDIX C
Quality Assessment Tools
Appendix C i
Cochrane Risk of Bias Tool STUDY DETAILS (citation):
5.1.1 Domain
Description (provide evidence from text and any further comments) Judgement
Adequate sequence generation Was the allocation sequence adequately generated?
Yes Unclear No
Allocation concealment Was allocation adequately concealed?
Yes Unclear No
Blinding Was knowledge of the allocated interventions adequately prevented during the study?
Yes Unclear No
Incomplete outcome data addressed Were incomplete outcome data adequately addressed?
Yes Unclear No
Free of selective reporting Are reports of the study free of suggestion of selective outcome reporting?
Yes Unclear No
Free of other bias Was the study apparently free of other problems that could put it at a high risk of bias?
Yes Unclear No
Adapted from Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.2 [updated September 2009]. The Cochrane Collaboration, 2009. Available from www.cochrane-handbook.org.
Appendix C ii
Cohort Studies
Trial ID: Details
Is there sufficient description of the groups and the distribution of prognostic factors?
Are the groups assembled at a similar point in their disease progression?
As the intervention/treatment reliable ascertained?
Were the groups comparable on all important confounding variables?
Was there adequate adjustment for the effect of these confounding variables?
Was a dose response relationship between intervention and outcome demonstrated?
Was outcome assessment blind to exposure status?
Was follow-up long enough for the outcomes to occur?
What proportion of the cohort was followed up?
Were drop-out rates and reasons for dropout similar across intervention and unexposed groups?
Case Control studies
Trial ID: Details
Is the case definition explicit?
Has the disease state of the cases been reliably assessed and validated?
Were the controls randomly selected from the source of population of the cases?
How comparable are the cases and controls with respect to potential confounding factors?
Were interventions and other exposures assessed in the same way for case and controls?
How was the response rate defined?
Were the non response rates and reasons for non response the same in both groups?
Is it possible that over matching has occurred in that cases and controls were matched on factors relating to exposure?
Was an appropriate statistical analysis used (matched or unmatched)?