Effect of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus: a systematic review.

Muley A, Fernandez R, Ellwood L, Muley P, Shah M.

JBI Evid Synth. 2021;19(5):966-1002.

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus.

A three step search of PubMed, CINAHL, Embase, Trip database, and Cochrane Central Register of Controlled Trials (CENTRAL) was done in July 2019.

The authors found that pistachio consumption for three months or less significantly reduced triglyceride levels. Other tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose and glycated hemoglobin levels by varying degrees. Further robust randomized controlled trials with power calculation-based sample size, comparing same type, dose, and method of nut intervention, will provide more evidence. For now, clinical decisions should be based on standard practice local guidelines.