Chartres N, Fabbri A, McDonald S, Diong J, McKenzie JE, Bero L. Association of food industry ties with findings of studies examining the effect of dairy food intake on cardiovascular disease and mortality: systematic review and meta-analysis.
BMJ Open 2020;
10:e039036. [PMID:
33277278 PMCID:
PMC7722392 DOI:
10.1136/bmjopen-2020-039036]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE
To determine if the association of dairy foods with cardiovascular disease (CVD) outcomes differs between studies with food industry ties versus those without industry ties. To determine whether studies with or without industry ties differ in their risk of bias.
ELIGIBILITY CRITERIA
We included cohort and case-control studies that estimated the association of dairy foods with CVD outcomes in healthy adults.
INFORMATION SOURCES
We searched eight databases on 1 February 2019 from 2000 to 2019 and hand searched reference lists.
RISK OF BIAS
We used the Risk of Bias in Non-Randomised Studies-of Exposure tool.
INCLUDED STUDIES
43 studies (3 case-controls, 40 cohorts).
SYNTHESIS OF RESULTS
There was no clear evidence of an association between studies with industry ties (1/14) versus no industry ties (8/29) and the reporting of favourable results, risk ratio (RR)=0.26 (95% CI 0.04 to 1.87; n=43 studies) and studies with industry ties (4/14) versus no industry ties (11/29) and favourable conclusions, RR=0.75 (95% CI 0.29 to 1.95; n=43). Studies with industry sponsorship, (HR=0.78; n=3 studies) showed a decreased magnitude of risk of CVD outcomes compared with studies with no industry sponsorship (HR=0.97; n=18) (ratio of HRs 0.80 (95% CI 0.66 to 0.97); p=0.03).
STRENGTHS AND LIMITATIONS OF EVIDENCE
Every study had an overall high risk of bias rating; this was primarily due to confounding.
INTERPRETATION
There was no clear evidence of an association between studies with food industry ties and the reporting of favourable results and conclusions compared with studies without industry ties. The statistically significant difference in the magnitude of effects identified in industry-sponsored studies compared with non-industry-sponsored studies, however, is important in quantifying industry influence on studies included in dietary guidelines.
PROSPERO REGISTRATION NUMBER
CRD42019129659.
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