Dietary nitrate supplementation in COPD: An acute, double-blind, randomized, placebo-controlled, crossover trial☆

Dietary nitrate increases exercise tolerance in patients with non-ischemic, dilated cardiomyopathy—a double-blind, randomized, placebo-controlled, crossover trial

“…As expected, NO 3 -supplementation led to a significant increase in plasma nitrite (48.5-fold) and particularly nitrate (428-fold). Similar to our COPD trial, 5 we observed marked variation in response to exogenous nitrate despite an identical dose and time interval (Figure 2b and c). We cannot explain these variations, but it is likely that differences in oral bacteria and stomach acidity, age and medication are contributing factors.…”

“…A second, NO synthase-independent pathway has recently been discovered and was found to be involved in simple reduction of dietary, inorganic nitrate to nitrite and NO. 2,3 Acute nitrate consumption has been shown to increase blood nitrate/nitrite levels and exercise performance in healthy, athletic, pulmonary vascular disease (PVD), 4 chronic obstructive pulmonary disease (COPD) 5 and heart failure (HF) subjects. 2 We hypothesized that dietary nitrate supplementation could acutely improve exercise capacity in NIDCM.…”

Effects of dietary nitrate supplementation on the oxygen cost of exercise and walking performance in individuals with type 2 diabetes: a randomized, double-blind, placebo-controlled crossover trial

“…Zamani et al [63] reported an improvement in exercise capacity (but no reduction in the oxygen cost of exercise) after beetroot juice supplementation in individuals with heart failure. Similar findings have been reported in individuals with peripheral artery disease [40] and chronic obstructive pulmonary disease [30,49,51]. It should be noted, however, that to date no study has shown a reduction in the oxygen cost of exercise in a patient group, despite reporting improvements in exercise tolerance.…”

“…This lack of effect has also been reported in individuals with chronic obstructive pulmonary disease [30,49,50]. These studies all had relatively small sample sizes (n ¼ 8 [47], 11 [48,51], 13 [49], and 15 [30]). …”

A critical examination of the ergogenic/therapeutic effects of supplementation to increase nitric oxide bioavailability

“…One study found no differences in blood pressures or six-minute walk distance whereas the other study showed an increase in median sub-maximal constant work rate exercise time of 28.8 seconds and lower diastolic blood pressures during exercise. Two other recent published studies in COPD have similarly conflicting results [11,12].…”