The effects of 100% wild blueberry (Vaccinium angustifolium) juice consumption on cardiometablic biomarkers: a randomized, placebo-controlled, crossover trial in adults with increased risk for type 2 diabetes

Authors: STOTE, KIM - State University Of New York (SUNY); SWEENEY, M - University Of Prince Edward Island; KEAN, T - University Of Prince Edward Island; Baer, David; Novotny, Janet; SHAKERLEY, N - State University Of New York (SUNY); CHANDRASEKARAN, A - State University Of New York (SUNY); CARRICO, P - State University Of New York (SUNY); MELENDEZ, J - State University Of New York (SUNY); GOTTSCHALL-PASS, K - State University Of New York (SUNY)

Submitted to: BMC Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2017
Publication Date: 5/25/2017
Citation: Stote, K.S., Sweeney, M.I., Kean, T., Baer, D.J., Novotny, J., Shakerley, N.L., Chandrasekaran, A., Carrico, P., Melendez, J.A., Gottschall-Pass, K.T. 2017. The effects of 100% wild blueberry (Vaccinium angustifolium) juice consumption on cardiometablic biomarkers: a randomized, placebo-controlled, crossover trial in adults with increased risk for type 2 diabetes. Biomed Central (BMC) Nutrition. 3. https://doi.org/10.1186/s40795-017-0164-0.
DOI: https://doi.org/10.1186/s40795-017-0164-0

Interpretive Summary: Type 2 diabetes is a costly global public health concern. Plant-based diets may help prevent and manage type 2 diabetes. In particular, the polyphenols found in many plants may help improve regulation of blood sugar (glucose) concentrations, and reduce the risk for diabetes. Wild blueberries have a high content of polyphenols but there is limited data evaluating their health benefits in individuals at-risk for type 2 diabetes. The objective of this research project was to investigate whether consumption of 100% wild blueberry juice improves biomarkers of glucoregulatory control, oxidative stress, inflammation, and vascular status, all of which are associated with diabetes risk. A study was conducted in which 19 women aged between 39-64 years and at-risk for type 2 diabetes consumed 240 mL of 100% wild blueberry juice or a control beverage as part of their free-living diet for 7 days. Blood was collected to determine various biomarkers associated with risk for diabetes, and endothelial function (assessing health of the blood vessels) and blood pressure were also measured. Wild blueberry juice consumption for 7 days produced no significant changes in glucose, insulin resistance, inflammatory markers, adhesion molecules, oxidative stress, or endothelial function. However, wild blueberry juice consumption showed a trend for lowering systolic blood pressure. Blood concentrations of nitrates and nitrites, an index of nitric oxide production, increased from 2.9 ± 0.4 µM after placebo drink to 4.1 ± 0.4 µM after drinking wild blueberry juice (P = 0.039). Short term consumption of 100% wild blueberry juice does not have harmful effects on glucose regulation, insulin resistance, oxidative stress, inflammation and vascular status in women at risk for type 2 diabetes. In addition, wild blueberry juice may improve systolic blood pressure by increasing nitric oxide production in the blood vessels, thereby lowering overall cardiovascular disease risk.

Technical Abstract: Plant-based diets help prevent and manage type 2 diabetes, attributed in part to polyphenols. Wild blueberries have a high content of polyphenols, but there is limited data evaluating their health benefits in individuals at risk for type 2 diabetes. The objective of this research project was to investigate whether consumption of 100% wild blueberry juice improves biomarkers of glucoregulatory control, oxidative stress, inflammation and vascular status, all of which are associated with diabetes risk. A single-blind, randomized, crossover design trial was conducted in which women (n = 19, ages 39-64 y) at risk for type 2 diabetes consumed 240 mL of 100% wild blueberry juice or a control beverage as part of their free-living diet for 7 days. Blood was collected to determine various biomarkers; endothelial function and blood pressure were also assessed. Wild blueberry juice consumption for 7 days produced no significant changes in glucose, insulin resistance, inflammatory markers, adhesion molecules, oxidative stress, or endothelial function. However, wild blueberry juice consumption showed a trend for lowering systolic blood pressure: 120.8 ± 2.2 mm Hg in the placebo group versus 116.0 ± 2.2 mm Hg in the blueberry juice group (P = 0.088). Serum levels of nitrates and nitrites, an index of nitric oxide production, increased from 2.9 ± 0.4 µM after placebo drink to 4.1 ± 0.4 µM after drinking wild blueberry juice (P = 0.039). Short term consumption of 100% wild blueberry juice does not have harmful effects on glucose regulation, insulin resistance, oxidative stress, inflammation and vascular status in women at risk for type 2 diabetes. In addition, wild blueberry juice may improve systolic blood pressure by increasing nitric oxide production in the vasculature, thereby lowering overall cardiovascular disease risk.