Acute dietary nitrate does not reduce resting metabolic rate or oxidative stress marker 8-isoprostane in healthy males and females

Abstract

To investigate changes in resting metabolic rate and 8-isoprostane, an oxidative stress biomarker, following acute dietary nitrate supplementation in healthy males and females. In a randomised, double-blind, cross-over study, 10 males and seven females (age range 19–25 years) underwent protocol familiarisation (visit 1), baseline assessments (visits 2 and 4) and assessments following supplementation, placebo or 6.2 mmol nitrate, 2 hours prior to visits 3 and 5. Participants completed a 30-minute RMR test with visits 2 and 3 on consecutive days, separated by a week-long washout period concluding with visits 4 and 5 on consecutive days. Plasma nitrate/nitrite (NOx) significantly increased (p ≤ 0.05) following dietary nitrate consumption compared to baseline values. No significant effect on resting metabolism (p = 0.194) or 8-isoprostane (p = 0.660) was observed following dietary nitrate supplementation. Dietary nitrate increases NO bioavailability, but acute supplementation does not effect resting metabolism or 8-isoprostane in healthy males and females.