Processed meat intake and chronic disease morbidity and mortality: An overview of systematic reviews and meta-analyses

Mina Nicole Händel; Isabel Cardoso; Katrine Marie Rasmussen; Jeanett Friis Rohde; Ramune Jacobsen; Sabrina Mai Nielsen; Robin Christensen; Berit Lilienthal Heitmann

doi:10.1371/journal.pone.0223883

Processed meat intake and chronic disease morbidity and mortality: An overview of systematic reviews and meta-analyses

PLoS One. 2019 Oct 17;14(10):e0223883. doi: 10.1371/journal.pone.0223883. eCollection 2019.

Authors

Affiliations

¹ The Parker Institute, Bispebjerg and Frederiksberg Hospital, University of Copenhagen, Copenhagen, Denmark.
² Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark.
³ Research Unit of Rheumatology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Odense, Denmark.
⁴ The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, University of Sydney, Sydney, Australia.
⁵ Department of Public Health, Section for General Practice, University of Copenhagen, Copenhagen, Denmark.

Abstract

Despite the nutritional value of meat, a large volume of reviews and meta-analyses suggests that processed meat intake is associated with an increased risk of chronic diseases. However, assessments of the quality of these published reviews internal validity are generally lacking. We systematically reviewed and assessed the quality alongside summarizing the results of previously published systematic reviews and meta-analyses that examined the association between processed meat intake and cancers, type II diabetes (T2D), and cardiovascular diseases (CVD). Reviews and meta-analyses published until May 2018 were identified through a systematic literature search in the databases MEDLINE and EMBASE, and reference lists of included reviews. The quality of the systematic reviews and meta-analyses was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). All eligible reviews had to comply with two quality requirements: providing sufficient information on quality assessment of the primary studies and a comprehensive search. The results were summarized for T2D, CVD, and each of the different cancer types. The certainty in the estimates of the individual outcomes was rated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. In total, 22 systematic reviews were eligible and thus included in this review. More than 100 reviews were excluded because quality assessment of the primary studies had not been performed. The AMSTAR score of the included reviews ranged from 5 to 8 indicating moderate quality. Overall, the quality assessments of primary studies of the reviews are generally lacking; the scientific quality of the systematic reviews reporting positive associations between processed meat intake and risk of various cancers, T2D and CVD is moderate, and the results from case-control studies suggest more often a positive association than the results from cohort studies. The overall certainty in the evidence was very low across all individual outcomes, due to serious risk of bias and imprecision.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Cardiovascular Diseases / diagnosis*
Cardiovascular Diseases / epidemiology
Cardiovascular Diseases / mortality
Chronic Disease
Databases, Factual
Diabetes Mellitus, Type 2 / diagnosis*
Diabetes Mellitus, Type 2 / epidemiology
Diabetes Mellitus, Type 2 / mortality
Humans
Meat Products / analysis*
Meat Products / toxicity
Neoplasms / diagnosis*
Neoplasms / epidemiology
Neoplasms / mortality
Risk Factors

Grants and funding

This work was funded by MatPrat – Norwegian Centre for Consumer Information: Egg and Meat. MatPrat had no role in study design, data collection, analysis, results, interpretation or preparation of this study. The Parker Institute, Bispebjerg and Frederiksberg Hospital is supported by a core grant from the Oak Foundation (OCAY-13-309).