Consumption of citrus and cruciferous vegetables with incident type 2 diabetes mellitus based on a meta-analysis of prospective study

Prim Care Diabetes. 2016 Aug;10(4):272-80. doi: 10.1016/j.pcd.2015.12.004. Epub 2016 Jan 6.


Background: Observational studies and meta-analyses suggested that increased total fruits and vegetables consumption have a protective role in incidence of type 2 diabetes mellitus (T2DM). However, we still don't know whether the subtypes, such as citrus fruits and cruciferous vegetables (CV), have a preventive role.

Methods: We systematically searched the MEDLINE and EMBASE databases up to December 31, 2014. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using random-effects models.

Results: Seven distinct prospective cohort studies (five articles) were identified for this study. A total of 16,544 incident cases of type 2 diabetes were ascertained among 306,723 participants with follow-up periods ranging from 4.6 to 24 years. Based on four prospective cohort studies, we found that overall, consumption of CV had a protective role in the T2DM incidence (highest vs. lowest analysis: SRR=0.84, 95% CI: 0.73 to 0.96), with evidence of significant heterogeneity (P=0.09, I(2)=54.4%). This association was independent of the main risk factors for cardiovascular disease: smoking, alcohol use, BMI, and physical activity etc. Consumption of citrus fruits did not have a protective role in the T2DM development (highest vs. lowest analysis: SRR=1.02, 95% CI: 0.96 to 1.08), with no evidence of significant heterogeneity (P=0.49, I(2)=0).

Conclusions: Higher consumption of CV, but not citrus fruits, is associated with a significantly decreased risk of type 2 diabetes. Further large prospective studies are needed to elucidate both relationships.

Keywords: Citrus fruits; Cruciferous vegetables; Type 2 diabetes mellitus.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Brassicaceae*
  • Citrus*
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Diet, Healthy*
  • Fruit*
  • Humans
  • Incidence
  • Odds Ratio
  • Prognosis
  • Prospective Studies
  • Protective Factors
  • Recommended Dietary Allowances
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Vegetables*