Blood pressure-lowering effects of beetroot juice and novel beetroot-enriched bread products in normotensive male subjects

A number of vegetables have a high nitrate content which after ingestion can be reduced to nitrite by oral bacteria, and further to vasoprotectiveNO endogenously. In the present study, two separate randomly controlled, single-blind, cross-over, postprandial studies wereperformed in normotensive volunteers. Ambulatory blood pressure (BP) was measured over a 24 h period following consumption of eitherfour doses of beetroot juice (BJ), 0, 100, 250 and 500 g (n 18), or three bread products, control bread (0 g beetroot), red beetroot- and whitebeetroot-enriched breads (n 14). Total urinary nitrate/nitrite (NOx) was measured at baseline, and at 2, 4 and 24 h post-ingestion. BJ consumptionsignificantly, and in a near dose-dependent manner, lowered systolic BP (SBP, P,0•01) and diastolic BP (DBP, P,0•001) over aperiod of 24 h, compared with water control. Furthermore, bread products enriched with 100 g red or white beetroot lowered SBP and DBPover a period of 24 h (red beetroot-enriched bread, P , 0•05), with no statistical differences between the varieties. Total urinary NOxsignificantly increased following the consumption of 100 g (P,0•01), 250 g (P , 0•001) and 500 g BJ (P , 0•001) and after red beetrootenrichedbread ingestion (P , 0•05), but did not reach significance for white beetroot-enriched bread compared with the no-beetrootcondition. These studies demonstrated significant hypotensive effects of a low dose (100 g) of beetroot which was unaffected by processingor the presence of betacyanins. These data strengthen the evidence for cardioprotective BP-lowering effects of dietary nitrate-rich vegetables