Background The association between intake of fruit and vegetables and their subtypes, and the risk of type 2 diabetes has been investigated in several studies, but the results have been inconsistent.
Objective We conducted an updated systematic review and dose–response meta-analysis of prospective studies on intakes of fruit and vegetables and fruit and vegetable subtypes and the risk of type 2 diabetes.
Design PubMed and Embase databases were searched up to 20 October 2020. Prospective cohort studies of fruit and vegetable consumption and type 2 diabetes mellitus were included. Summary relative risks (RRs) and 95% CIs were estimated using a random effects model.
Results We included 23 cohort studies. The summary RR for high versus low intake and per 200 g/day were 0.93 (95% CI: 0.89 to 0.98, I2=0%, n=10 studies) and 0.98 (95% CI: 0.95 to 1.01, I2=37.8%, n=7) for fruit and vegetables combined, 0.93 (95% CI: 0.90 to 0.97, I2=9.3%, n=20) and 0.96 (95% CI: 0.92 to 1.00, I2=68.4%, n=19) for fruits and 0.95 (95% CI: 0.88 to 1.02, I2=60.4%, n=17) and 0.97 (95% CI: 0.94 to 1.01, I2=39.2%, n=16) for vegetables, respectively. Inverse associations were observed for apples, apples and pears, blueberries, grapefruit and grapes and raisins, while positive associations were observed for intakes of cantaloupe, fruit drinks, fruit juice, brussels sprouts, cauliflower and potatoes, however, most of these associations were based on few studies and need further investigation in additional studies.
Conclusions This meta-analysis found a weak inverse association between fruit and vegetable intake and type 2 diabetes risk. There is indication of both inverse and positive associations between intake of several fruit and vegetables subtypes and type 2 diabetes risk, however, further studies are needed before firm conclusions can be made.
- Diabetes mellitus
Data availability statement
Data are available on reasonable request. Analytical datasets and Stata do-files are available from DA (firstname.lastname@example.org) on reasonable request.
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REH and ME are joint first authors.
Contributors ME and REH had full access to the data, conducted the statistical analyses, wrote the first draft of the manuscript and take responsibility for the integrity of the data and the accuracy of the data analysis. DA contributed towards the statistical analysis, and all authors contributed to the revision of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests No, there are no competing interests.
Provenance and peer review Not commissioned; externally peer reviewed.
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