To What Extent Does Greater Diversity of the Diet Prevent Cardiovascular Diseases and Related Mortality? A Systematic Review and Meta-Analysis

Abstract

\n \n \n Dietary diversity is linked to factors associated with the development of cardiovascular diseases (CVDs), such as improved dyslipidemia and insulin resistance. However, the role of dietary diversity in the risk of CVDs has remained controversial. This meta-analysis assessed whether greater diversity across the diet and within food groups can protect against CVDs and related mortality.\n \n \n \n A systematic search was done using bibliographic databases of PubMed/Medline, Scopus, and Web of Science for longitudinal studies published between 2008–2020 from developed countries. Random-effects models pooled risk ratios (RR) and 95% confidence intervals (CI); the Cochrane Q test and subgroup analysis assessed heterogeneity and its potential sources. Sensitivity analysis checked for robustness of findings and Egger test assessed publication bias.\n \n \n \n From the 6713 results, 4,950 titles and abstracts were screened for eligibility to provide, respectively, 8 included CVD studies (437,244 participants and 18,820 cases) and 7 included CVD-mortality studies (160,877 participants and 5,631 cases). All studies were assessed as high or moderate quality. There was a small inverse but non-significant association between total dietary diversity and CVDs (RR: 0.93 [95% CI: 0.86, 1.00], I² = 31.7%), which was driven by the effect in non-European populations and the diversity measured by food groups not foods. Moreover, total dietary diversity was inversely but non-significantly associated with mortality from CVDs (RR: 0.83 [95% CI: 0.70, 1.00], I² = 46.1%). This relationship was significant when studies used >3 categories of exposure, FFQ assessment tool, were conducted on non-Europeans, had ≥10,000 participants, and adjusted for energy intake. These subgroup characteristics were sources of heterogeneity. Studies reporting diversity within food groups could only be pooled for the association between vegetables diversity and CVD mortality, which was null. We found no evidence of publication bias or a single study driving the observed associations.\n \n \n \n Findings indicated greater total dietary diversity may benefit CVDs and related mortality in non-European populations. More research is needed regarding within-group diversity.\n \n \n \n None.\n