Affiliation:
1. Department of Food Science and Nutrition, Zhejiang University, Hangzhou, China
2. Zhejiang Key Laboratory for Agro-Food Processing, Hangzhou, China
3. School of Life Sciences, Westlake University, Hangzhou, China
4. Institute of Basic Medical Science, Westlake Institute for Advanced Study, Westlake University, Hangzhou, China
Abstract
ABSTRACT
Background
Previous findings on the associations of legume and soy intake with the risk of type 2 diabetes are conflicting.
Objective
We aimed to summarize the longitudinal associations between legume and soy intake and risk of type 2 diabetes.
Methods
We searched for relevant prospective cohort studies in PubMed, EMBASE, and Ovid up to August 2019. Study-specific, multivariable-adjusted RRs and 95% CIs were pooled by random-effects models.
Results
We identified 15 unique cohorts including 565,810 individuals and 32,093 incident cases. The summary RRs (95% CIs) of incident type 2 diabetes were 0.95 (0.79, 1.14; NS) for total legumes, 0.83 (0.68, 1.01; NS) for total soy, 0.89 (0.71, 1.11; NS) for soy milk, 0.92 (0.84, 0.99) for tofu, 0.84 (0.75, 0.95) for soy protein, and 0.88 (0.81, 0.96) for soy isoflavones, respectively. High heterogeneity was found for total legumes (I2 = 84.8%), total soy (I2 = 90.8%), and soy milk (I2 = 91.7%). Potential sources of heterogeneity were not evident for total legumes or soy milk, whereas for total soy, geographic location (Asia, United States; P = 0.04) and study quality (high, moderate, or low; P = 0.02) significantly predicted heterogeneity. In dose–response analysis, significant linear inverse associations were observed for tofu, soy protein, and soy isoflavones (all P < 0.05). Overall quality of evidence was rated as moderate for total legumes and low for total soy and soy subtypes.
Conclusions
Dietary intakes of tofu, soy protein, and soy isoflavones, but not total legumes or total soy, are inversely associated with incident type 2 diabetes. Our findings support recommendations to increase intakes of certain soy products for the prevention of type 2 diabetes. However, the overall quality of evidence was low and more high-quality evidence from prospective studies is needed. This trial was registered as PROSPERO CRD42019126403 (https://www.crd.york.ac.uk/PROSPERO).
Funder
Natural Science Foundation of Zhejiang Province
Zhejiang University New Rural Development Research Institute Agricultural Technology Promotion Fund
Publisher
Oxford University Press (OUP)
Subject
Nutrition and Dietetics,Medicine (miscellaneous)