Effect of Blueberry Consumption on Cardiometabolic Health Parameters in Men with Type 2 Diabetes: An 8-Week, Double-Blind, Randomized, Placebo-Controlled Trial

Kim S Stote; Margaret M Wilson; Deborah Hallenbeck; Krista Thomas; Joanne M Rourke; Marva I Sweeney; Katherine T Gottschall-Pass; Aidar R Gosmanov

doi:10.1093/cdn/nzaa030

Effect of Blueberry Consumption on Cardiometabolic Health Parameters in Men with Type 2 Diabetes: An 8-Week, Double-Blind, Randomized, Placebo-Controlled Trial

Curr Dev Nutr. 2020 Mar 9;4(4):nzaa030. doi: 10.1093/cdn/nzaa030. eCollection 2020 Apr.

Authors

Kim S Stote¹, Margaret M Wilson², Deborah Hallenbeck³, Krista Thomas⁴, Joanne M Rourke², Marva I Sweeney⁵, Katherine T Gottschall-Pass⁶, Aidar R Gosmanov²

Affiliations

¹ Department of Research, Stratton VA Medical Center, Albany, NY, USA.
² Department of Endocrinology, Stratton VA Medical Center, Albany, USA.
³ Department of Primary Care Services, Stratton VA Medical Center, Albany, NY, USA.
⁴ School of Health Science, The Sage Colleges, Troy, NY, USA.
⁵ Department of Biology, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada.
⁶ Department of Applied Human Sciences, University of Prince Edward Island, Charlottetown, Prince Edward Island, Canada.

Abstract

Background: Blueberries are dietary sources of polyphenols, specifically anthocyanins. Anthocyanins have been identified as having a strong association with type 2 diabetes risk reduction; however, to date few human clinical trials have evaluated the potential beneficial health effects of blueberries in populations with type 2 diabetes.

Objectives: We investigated the effects of blueberry consumption for 8 wk on cardiometabolic parameters in men with type 2 diabetes.

Methods: In a double-blind, parallel-arm, randomized controlled trial, 52 men who are US veterans [mean baseline characteristics: age, 67 y (range: 51-75 y); weight, 102 kg (range: 80-130 kg); BMI (in kg/m²), 34 (range: 26-45)] were randomly assigned to 1 of 2 intervention groups. The interventions were either 22 g freeze-dried blueberries or 22 g placebo. The study participants were asked to consume 11 g freeze-dried blueberries or placebo with each of their morning and evening meals along with their typical diet.

Results: Mean ± SE hemoglobin A1c (7.1% ± 0.1% compared with 7.5% ± 0.2%; P = 0.03), fructosamine (275.5 ± 4.1 compared with 292.4 ± 7.9 µmol/L; P = 0.04), triglycerides (179.6 ± 10.1 compared with 199.6 ± 19.9 mg/dL; P = 0.03), aspartate transaminase (23.2 ± 1.4 compared with 30.5 ± 2.7 units/L; P = 0.02), and alanine transaminase (35.6 ± 1.5 compared with 48.3 ± 2.9 units/L; P = 0.0003) were significantly lower for those consuming blueberries for 8 wk than for those consuming the placebo. Fasting plasma glucose concentrations; serum insulin, total cholesterol, LDL-cholesterol, HDL-cholesterol, and C-reactive protein concentrations; blood pressure; and body weight were not significantly different after 8 wk consumption of blueberries compared with the placebo.

Conclusions: Consumption of 22 g freeze-dried blueberries for 8 wk may beneficially affect cardiometabolic health parameters in men with type 2 diabetes.This trial was registered at clinicaltrials.gov as NCT02972996.

Keywords: anthocyanins; blueberries; flavonoids; polyphenols; type 2 diabetes.

Associated data

ClinicalTrials.gov/NCT02972996