Fruit and vegetable consumption and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of prospective studies.

Dagfinn Aune, Rine Elise Halvorsen, Mathilde Elvestad, Marianne Molin

Journal: BMJ nutrition, prevention & health 2021;4(2):519-531

PMID: 35028521

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Plain Language Summary

Type 2 diabetes is a growing health concern worldwide, with projections estimating it will affect over 700 million people by 2045. Studies have indicated a link between increased consumption of fruits and vegetables and decreased risk of Type 2 diabetes. This systematic review and meta-analysis of twenty-three prospective cohort studies explored this link further, examining the effects of different types of fruits and vegetables on the risk of Type 2 diabetes. The results suggest that a high intake of combined fruits and vegetables and specific varieties, such as apples, pears, blueberries, grapes, and raisins, may slightly reduce the risk of developing Type 2 diabetes. However, consuming cantaloupe, fruit drinks, fruit juice, potatoes, Brussels sprouts, and cabbage may increase the risk of developing Type 2 diabetes. The protective effect of fruit and vegetable consumption on the reduction of type 2 diabetes could be attributed to the dietary fibre, antioxidants, vitamins and minerals and phytochemicals present in fruits and vegetables. While further studies are necessary to confirm these results and explore the impact of specific types of fruits and vegetables on Type 2 diabetes risk, healthcare professionals can use this information to promote the protective benefits of including specific subtypes of fruits and vegetables in the diet to reduce the risk of Type 2 diabetes.

Abstract

[{"label":"BACKGROUND","text":"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."},{"label":"OBJECTIVE","text":"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."},{"label":"DESIGN","text":"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."},{"label":"RESULTS","text":"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, I=0%, n=10 studies) and 0.98 (95% CI: 0.95 to 1.01, I=37.8%, n=7) for fruit and vegetables combined, 0.93 (95% CI: 0.90 to 0.97, I=9.3%, n=20) and 0.96 (95% CI: 0.92 to 1.00, I=68.4%, n=19) for fruits and 0.95 (95% CI: 0.88 to 1.02, I=60.4%, n=17) and 0.97 (95% CI: 0.94 to 1.01, I=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."},{"label":"CONCLUSIONS","text":"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."},{"copyright":"\u00a9 Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ."}]

Address: Department of Nursing and Health Promotion, Faculty of Health Science, Oslo Metropolitan University, Oslo, Norway.; Department of Nutrition, Bjørknes University College, Oslo, Norway.; Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK.; Department of Endocrinology, Morbid Obesity and Preventive Medicine, Oslo University Hospital, Oslo, Norway.; Unit of Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.

DOI: 10.1136/bmjnph-2020-000218