Systematic Review of the Health Benefits of Vegetarian and Vegan Diets in the Management of Adults with Diabetes Mellitus Type 2
Creators: name: Hoden, Ingrid
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2018

description: Introduction:  The prevalence of type 2 diabetes mellitus (DM) is rapidly increasing and recent estimates rank type 2 DM as the 7th leading cause of death in the United States. Although some evidence suggests that consuming a vegetarian diet may lead to better glycemic control and improved metabolic outcomes compared with a conventional hypocaloric diet among persons with type 2 DM, there is uncertainty regarding the magnitude of benefit and the specific outcomes that show benefit.  Medical costs associated with diabetes, overweight, heart disease, lipid disorders and hypertension are a significant cost to the healthcare system and employers.  The need for reductions in these illnesses is driven by both medical and economic concerns and requires a targeted approach in both the patient-care and workplace settings.Objective: To conduct a systematic review of clinical trials evaluating the benefit of vegan and vegetarian diets for improving glycemic control and other metabolic outcomes in type 2 DMMethods:  Data source: PubMed, EMBASE, Cochrane and the Clinical Trails databases were searched for trials published in the English language in the last ten years through April 4, 2018. The following criteria were used for study inclusion: (1) studies enrolling adults (18 years or older); (2) vegan or vegetarian diet as the intervention; and (3) participants had a previous diagnosis of type 2 DM.  Main outcome measures were HbA1c, body weight and LDL levels. Critical appraisal and abstraction of relevant data from studies was performed by one author. Results: Eight studies met inclusion criteria (785 total participants, mean age 53 years).  Vegan and vegetarian diets were shown to be associated with a significant reduction in HbA1c, body weight, and LDL levels.  Consumption of a vegan or vegetarian diet yielded a decrease in HbA1c  of -0.40% to -0.65% in the intervention arm of the four best studies.   These same studies had an HbA1c change in the control arm of -0.08% to 0.21%.   The difference between intervention and control groups mean change in HbA1c was reported with statistical significance in five studies with a range of -1.5% to -0.7 %.  In the three of the studies reporting on BMI, differences between groups in mean changes from baseline were all statistically significant and ranged from  -1.0 kg/m2 to -3.9 kg/m2.   In four of the studies reporting on weight change, differences between groups in mean changes from baseline were all statistically significant and ranged from -2.8 kg to -10.6 kg.  In four of the studies reporting on LDL, differences between groups in mean changes from baseline were all statistically significant and ranged from -7.2 mg/dL to -0.54 mg/dL.Conclusion:   This systematic review supports the evidence from clinical trials that vegan and vegetarian diets reduce HbA1c levels and results in weight loss in adults with type 2 diabetes.  The health benefits of introducing a vegan or vegetarian diet program, at home or in a corporate setting, can lead to improving the management of type 2 DM in adults, and reducing morbidity and mortality of type 2 DM.