Acute beet juice ingestion improves estimates of insulin sensitivity in obese adults

Beals, Joseph William, author
Bell, Christopher, advisor
Hickey, Matthew, committee member
Gentile, Christopher, committee member
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Colorado State University. Libraries
Poor glucose regulation is strongly associated with low nitric oxide (NO) bioavailability; a characteristic that may be improved with stimulation of NO generating pathways. For example, endothelial nitric oxide synthase null mice demonstrate improved glucose metabolism following sodium nitrate ingestion. Dietary nitrates are sequentially reduced in the oral and gastric cavities to NO, a process that is attenuated by rinsing with an antibacterial mouthwash. We hypothesized that acute dietary nitrate consumption will improve glucose tolerance. 9 sedentary, healthy, obese adults (2 male; body mass index: 33.7 ± 4.0 kg/m2: age: 45±7 years; mean ± SE) were studied. Using a randomized crossover design, four oral glucose tolerance tests were performed (equal carbohydrate load). To assess the influence of dietary nitrate, subjects consumed either 500mL of beet juice + 25g glucose, or 500mL of water + 75g glucose, with and without prior antibacterial mouthwash use. Beet juice was selected because it is rich in nitrate. Venous blood samples were collected for the determination of glucose and insulin concentrations. Neither the circulating glucose nor insulin responses were influenced by beet juice and/or mouthwash (P>0.05). However, the Matsuda Index, an estimate of insulin sensitivity, was greater for beet juice compared with beet juice preceded by mouthwash (104.6 ± 11.7 vs. 83.5 ± 11.1; P<0.05). These preliminary data suggest that acute dietary nitrate ingestion may promote insulin sensitivity in obese adults.
2014 Summer.
Includes bibliographical references.
beet, tolerance, Matsuda, insulin, glucose