Effect of tree nuts on glycemic control in diabetes: a systematic review and meta‐analysis of randomized controlled dietary trials (1025.16)

Background: Tree nut consumption is associated with reduced diabetes risk, however, results from randomized trials on glycemic control have been inconsistent. Aim: We conducted a systematic review and meta‐analysis of randomized controlled trials to assess the effect of tree nuts on glycemic control in individuals with diabetes. Methods: We searched MEDLINE, EMBASE, CINAHL, and Cochrane databases through 14 May 2013 for relevant randomized trials 蠅3‐weeks reporting HbA1c, fasting glucose, fasting insulin, and/or HOMA‐IR. Two independent reviewers extracted relevant data. Data were pooled using the generic inverse variance method and expressed as mean differences (MD) with 95% confidence intervals (CI). Heterogeneity was assessed by Cochran’s Q and quantified by I2. Results: 10 trials (n=374) met the eligibility criteria. Diets emphasizing tree nuts significantly lowered HbA1c (MD=‐0.11 %, 95% CI:‐0.18, ‐0.04 %; P=0.001) and fasting glucose (MD=‐0.20 mmol/L, 95% CI:‐0.38, ‐0.03 mmol/L; P=0.02) compared with isocaloric control diets. No significant treatment effects were observed for fasting insulin and HOMA‐IR. Limitations: Majority of trials were of poor quality and short duration. Conclusion: Pooled analyses show diets high in tree nuts improve glycemic control in individuals with type 2 diabetes. Longer, higher quality trials are needed. Clinicaltrials.gov identifier: NCT01630980 Grant Funding Source : International Tree Nut Council Nutrition Research & Education Foundation