Dietary Fiber Intake and Type 2 Diabetes Mellitus: An Umbrella Review of Meta-analyses.
J Chiropr Med. 2018 Mar ;17(1):44-53. Epub 2018 Mar 1. PMID: 29628808
Marc P McRae
Objective: The purpose of this study was to review previously published meta-analyses on the effectiveness of dietary fiber on type 2 diabetes.
Methods: An umbrella review of all published meta-analyses was performed. A PubMed search from January 1, 1980, to April 30, 2017, was conducted using the following search strategy: (fiber OR glucan OR psyllium) AND (meta-analysis OR systematic review). Only English-language publications that provided quantitative statistical analysis on type 2 diabetes, fasting blood glucose concentrations, or glycosylated hemoglobin were retrieved.
Results: Sixteen meta-analyses were retrieved for inclusion in this umbrella review. In the meta-analyses comparing highest versus lowest dietary fiber intake, there was a statistically significant reduction in the relative risk (RR) of type 2 diabetes (RR = 0.81-0.85), with the greatest benefit coming from cereal fibers (RR = 0.67-0.87). However, statistically significant heterogeneity was observed in all of these meta-analyses. In the meta-analyses of supplementation studies usingβ-glucan or psyllium fibers on type 2 diabetic participants, statistically significant reductions were identified in both fasting blood glucose concentrations and glycosylated hemoglobin percentages.
Conclusion: This review suggests that those consuming the highest amounts of dietary fiber, especially cereal fiber, may benefit from a reduction in the incidence of developing type 2 diabetes. There also appears to be a small reduction in fasting blood glucose concentration, as well as a small reduction in glycosylated hemoglobin percentage for individuals with type 2 diabetes who addβ-glucan or psyllium to their daily dietary intake.