## 6 Efficacy  
Dietary nitrate in the form of unconcentrated and concentrated beetroot juice [16; 18; 28; 53; 65; 66], alongside whole vegetables--including, but not restricted to, whole beetroot [67], spinach [68], lettuce [69], mixed green leafy vegetables [70], and traditional Japanese vegetables, such as ta cai, chin gin cai, and garland chrysanthemum [71] (Table 3)--has been demonstrated to improve health parameters (especially blood pressure) and/or enhance exercise performance. This suggests that both juiced and whole-vegetable sources of nitrate can be effective at eliciting potentially beneficial effects, if a sufficient nitrate dose is administered [26]. Interestingly, several studies have compared the health and/or exercise performance effects of nitrate-rich beetroot juice against nitrate salts, and have demonstrated superior BP-lowering effects [63], greater reductions in oxygen consumption during steady-state exercise [72], and more pronounced attenuation of muscle pain after damaging exercise [73; 74] with beetroot juice. Here, it is argued that the presence of compounds such as polyphenols and antioxidants in the beetroot juice may elicit effects synergistically to the nitrate (e.g., by potentiating nitrite reduction into NO and/or reducing NO degradation by mitigating superoxide scavenging) [75; 76]. Similarly, [PERSON] et al. [77] demonstrated greater BP-lowering effects of concentrated beetroot juice versus unconcentrated beetroot juice, a beetroot flapjack, and a drink containing nitrate crystals, providing further evidence that the form in which nitrate is consumed could impact its effects in the body. In contrast, there are few head-to-head comparisons between beetroot juice'shots' and other vegetable sources of nitrate, which make it difficult to conclusively state whether one is superior (in terms of efficacy) to the other. Some relevant evidence comes from a study by [PERSON] and colleagues [63], who contrasted the effects of acute ingestion of concentrated beetroot juice against a rocket salad beverage, spinach beverage, and sodium nitrate solution (all containing 800 mg nitrate). In this study, all of the vegetable sources of nitrate were more effective at reducing BP than the sodium nitrate supplement, with no appreciable difference between the BP-lowering effects of concentrated beetroot juice and the spinach or rocket beverages. Interestingly, there were some differences in the plasma nitrate and nitrite response between supplements, which might suggest small differences in the optimal timing for ingesting each of the different nitrate sources, and requires further investigation. In another study by the same group, [PERSON] et al. [64] explored the BP-lowering effects of concentrated beetroot juice versus a variety of whole nitrate-rich vegetables (e.g., spinach, lettuce, arugia, bok choy) over a 1-week period. Although the concentrated beetroot juice resulted in greater increases in plasma nitrate and nitrite concentrations, both interventions were similarly effective at reducing systolic and diastolic BP (both by \(\sim\)5 mmHg) [64]. Although additional head-to-head comparisons are required, from the limited evidence available, it is clear that both concentrated beetroot juice and vegetables can be effective at increasing nitrate intake and, consequently, impacting health parameters. Assuming similar doses are administered, it appears likely that the effects of dietary nitrate via concentrated beetroot juice and other vegetable sources are broadly comparable [26].