Cited by 150Nuts composition and effectsNutritional Studies and DietDiabetes, Cardiovascular Risks, and Lipoproteins

The DOI matches its Crossref record; 82 of the 85 references it cites were found in a registry or an index.

Effect of tree nuts on metabolic syndrome criteria: a systematic review and meta-analysis of randomised controlled trials

Open access

Abstract

Objective: To provide a broader evidence summary to inform dietary guidelines of the effect of tree nuts on criteria of the metabolic syndrome (MetS). Design: We conducted a systematic review and meta-analysis of the effect of tree nuts on criteria of the MetS. Data sources: We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library (through 4 April 2014). Eligibility criteria for selecting studies: We included relevant randomised controlled trials (RCTs) of ≥3 weeks reporting at least one criterion of the MetS. Data extraction: Two or more independent reviewers extracted all relevant data. Data were pooled using the generic inverse variance method using random effects models and expressed as mean differences (MD) with 95% CIs. Heterogeneity was assessed by the Cochran Q statistic and quantified by the I 2 statistic. Study quality and risk of bias were assessed. Results: Eligibility criteria were met by 49 RCTs including 2226 participants who were otherwise healthy or had dyslipidaemia, MetS or type 2 diabetes mellitus. Tree nut interventions lowered triglycerides (MD=−0.06 mmol/L (95% CI −0.09 to −0.03 mmol/L)) and fasting blood glucose (MD=−0.08 mmol/L (95% CI −0.16 to −0.01 mmol/L)) compared with control diet interventions. There was no effect on waist circumference, high-density lipoprotein cholesterol or blood pressure with the direction of effect favouring tree nuts for waist circumference. There was evidence of significant unexplained heterogeneity in all analyses (p<0.05). Conclusions: Pooled analyses show a MetS benefit of tree nuts through modest decreases in triglycerides and fasting blood glucose with no adverse effects on other criteria across nut types. As our conclusions are limited by the short duration and poor quality of the majority of trials, as well as significant unexplained between-study heterogeneity, there remains a need for larger, longer, high-quality trials. Trial registration number: NCT01630980.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1136/bmjopen-2013-004660

Cites

82 of 82 references verified0 citation errors · 0 not checkable

Statistics

Figures

Figure 1 Summary of evidence search and selection.
Figure 1 Summary of evidence search and selection.CC BY-NC · PubMed Central
Figure 2 Forest plot of the randomised controlled trials (RCTs) investigating the effect of tree nuts on triglycerides (TG). Pooled effect estimates are shown as diamonds, one each for trials conducted in otherwise healthy, dyslipidaemia, metabolic syndrome criteria, type 2 diabetes mellitus and their combination (total). Paired analyses were applied to all cross-over trials (20) and one substudy. Data are expressed as mean differences with 95% CI, using generic inverse-variance random effects models. Interstudy heterogeneity was tested by using the Cochran Q statistic (Chi2) at a significance level of p<0.10 and quantified by the I2 statistic.
Figure 2 Forest plot of the randomised controlled trials (RCTs) investigating the effect of tree nuts on triglycerides (TG). Pooled effect estimates are shown as diamonds, one each for trials conducted in otherwise healthy, dyslipidaemia, metabolic syndrome criteria, type 2 diabetes mellitus and their combination (total). Paired analyses were applied to all cross-over trials (20) and one substudy. Data are expressed as mean differences with 95% CI, using generic inverse-variance random effects models. Interstudy heterogeneity was tested by using the Cochran Q statistic (Chi2) at a significance level of p<0.10 and quantified by the I2 statistic.CC BY-NC · PubMed Central
Figure 3 Pooled effect estimates are shown as diamonds, one each for trials conducted in otherwise healthy, dyslipidaemia, metabolic syndrome criteria, type 2 diabetes mellitus and their combination (total). Paired analyses were applied to all cross-over trials (10) and one substudy. Data are expressed as mean differences with 95% CI, using generic inverse-variance random effects models. Interstudy heterogeneity was tested by using the Cochran Q statistic (Chi2) at a significance level of p<0.10 and quantified by the I2 statistic. FBG, fasting blood glucose; RCT, randomised controlled trial.
Figure 3 Pooled effect estimates are shown as diamonds, one each for trials conducted in otherwise healthy, dyslipidaemia, metabolic syndrome criteria, type 2 diabetes mellitus and their combination (total). Paired analyses were applied to all cross-over trials (10) and one substudy. Data are expressed as mean differences with 95% CI, using generic inverse-variance random effects models. Interstudy heterogeneity was tested by using the Cochran Q statistic (Chi2) at a significance level of p<0.10 and quantified by the I2 statistic. FBG, fasting blood glucose; RCT, randomised controlled trial.CC BY-NC · PubMed Central

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

3 retracted

Research works printed but not linked: 3

  1. US Food and Drug Administration. Guidance for industry: evidence-based review system for the scientific evaluation of health claims—final, 2009.
  2. Berryman, 2013, Daily inclusion of almonds (1.5 ounces) in a cholesterol-lowering diet maintains HDL-cholesterol and HDL subclasses in mildly hypercholesterolemic adults, Ann Nutr Metab, 63, 1338
  3. 10.7326/0003-4819-151-5-200909010-00004 · DOI · Paper page

Cited by

Sorted by citations

See all 150

Metadata

Authors
Blanco Mejia, S., Kendall, C. W. C., Viguiliouk, E., Augustin, L. S., Ha, V., Cozma, A. I., Mirrahimi, A., Maroleanu, A., Chiavaroli, L., Leiter, L. A., de Souza, R. J., Jenkins, D. J. A., & Sievenpiper, J. L.
Affiliations
  • Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
  • St. Michael's Hospital (CA)
Corresponding author
Kendall, Cyril W C
Venue
BMJ Open
Publisher
BMJ
Published
2014-07
Volume
4
Issue
7
Pages
e004660
ISSN
2044-6055 (ISSN-L)
OpenAlex
W2113378946
Cited by
150
References
85
Citations by year
2026: 3 · 2025: 3 · 2024: 23 · 2023: 13 · 2022: 9 · 2021: 22 · 2020: 16 · 2019: 9 · 2018: 14 · 2017: 16 · 2016: 6 · 2015: 15 · 2014: 1
FWCI
1.45
Type
journal article
Language
en
Open access
Licence
cc-by-nc
Locations
  • BMJ Open (publishedVersion, cc-by-nc)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • HighWire Press Open Archive (submittedVersion)
Funders
  • Coca-Cola Foundation
  • Innovative Research Group Project of the National Natural Science Foundation of China
  • Canola Council of Canada
  • Canadian Institutes of Health Research (129920)
Topics
  • Health Sciences › Nursing › Nutrition and Dietetics › Nuts composition and effects
  • Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Nutritional Studies and Diet
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes, Cardiovascular Risks, and Lipoproteins
Keywords
tree nuts, metabolic syndrome, triglycerides, fasting blood glucose, waist circumference, HDL cholesterol, blood pressure, dietary intervention, dyslipidemia, type 2 diabetes, dietary guidelines
MeSH terms
Humans, Lipids, Nuts, Trees, Randomized Controlled Trials as Topic, Metabolic Syndrome, Lipid Metabolism

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review