Effect of Blueberry Consumption on Mood States in Men With Type 2 Diabetes

Objectives The study investigated the effects of blueberry consumption for 8 weeks on subjective mood states in men with type 2 diabetes. Methods In a double-blind, parallel randomized controlled trial, 37 men who are U.S. veterans (mean baseline characteristics: 67 years, range: 51–74 years; body mass index (BMI), 34 kg/m2, range: 26–44 kg/m2) were randomly assigned to 1 of 2 intervention groups. The interventions were either 22 g of freeze-dried blueberries (equivalent to 1 cup fresh blueberries) or 22 g of a placebo (matched in energy and carbohydrate content to the blueberries). The Profile of Mood States (POMS) was assessed twice using POMS 2 65-item questionnaire at the beginning (week 0) and at the end of the study (week 8). Increases in Vigor-Activity and Friendliness scores indicate a positive mood state. Increases in Total Mood Disturbance, Anger-Hostility, Confusion-Bewilderment, Depression-Dejection, Fatigue-Inertia, and Tension-Anxiety scores indicate a negative mood state. Results Vigor-Activity, Friendliness, Total Mood Disturbance, Anger-Hostility, Confusion-Bewilderment, Depression-Dejection, Fatigue-Inertia and Tension-Anxiety scores were not significantly different after 8 weeks of consumption of blueberries compared with the placebo. Total Mood Disturbance (38.7 ± 1.8 vs. 41.1 ± 2.5, respectively; P = 0.034) and Confusion-Bewilderment (37.3 ± 2.1 vs. 41.6 ± 3.0, respectively; P = 0.044) scores were significantly lower for those consuming blueberries for 8 weeks compared with the placebo in subgroup analysis of men with lower baseline Total Mood Disturbance scores (<45). Conclusions Consumption of 22 g freeze-dried blueberries for 8 weeks may beneficially affect some mood states in men with type 2 diabetes. Funding Sources The U.S. Highbush Blueberry Council; the study is the result of work supported with resources and the use of facilities at the Stratton VA Medical Center, Albany, NY, USA.